Maria Grazia Bridelli received her academic degree in Physics in 1979, address in Biophysics, from the University of Parma. In 1985 she obtained the postgraduate specialization in Solid State Physics. Since June 1983 she is researcher at the Department of Science of Mathematic, Physics and Computer Sciences of the University of Parma. She taught both in basic physics at the Department of Engineering and Biosciences (Environmental Sciences and Biotechnologies) and in specializing courses of the Biophysics address of the degree course in Physics (Biophysics laboratory, Molecular Biophysics) and in Science for Cultural Heritage (Biomolecular archaeology). Her research activity mainly concerns Melanin biophysical properties and hydration structure of biological macromolecules addressed by means of the development of Infrared and Dielectric spectroscopies. In the last 10 years her research interest was concerned the biomolecular archaeology field with specific attention to the survival conditions and mechanisms of ancient biomolecules in mummified tissues (skin and bone) and embalming substances characterization, studied by means of histologic analysis, SEM imaging, FTIR and micro FTIR spectroscopies. The studies were performed in collaboration with the Museum of Anthropology and Ethnography of University of Turin and with the Department of Cultural Heritage of University of Bologna to assess the state of conservation and on-going degradation processes of the mummified remains, to set up exhibition and storage conditions, and to plan conservation. She is secretary of Società Italiana di Biologia Sperimentale (SIBS) since 2014 She is member of the Editorial Board of Journal of Biological Research
Between 2009 and 2011, during restorative works at the Church of Roccapelago (province of Modena,... more Between 2009 and 2011, during restorative works at the Church of Roccapelago (province of Modena, Italy) a remote mountain village, hundreds of bodies, some of them mummified because of natural processes, were discovered in a forgotten crypt in use from the mid-16th to the 18th centuries. Mummification processes occurred unevenly, with bodies partially skeletonized and bodies only partly articulated [1]. 12 of these mummies, the most complete and representative, were studied with non-invasive methods and replaced in the crypt, set up as a museum (Fig. 1). The objects of this study are fragments of a variety of tissues taken from the mummies of the US 23 of the crypt of Roccapelago: skin pieces taken from different parts of the body, muscle, tendon, lung, bone, hair… The tissues were analyzed by means of FTIR spectroscopy applied in the transmission geometry, on samples obtained by mixing small quantities of the samples with pulverized KBr. In the IR spectrum of the investigated tissues the main absorption bands of the biological components such as proteins, lipids, nucleic acids, and carbohydrates were detected and characterized. The biochemical modifications recorded reveal a partial alteration of the ancient tissues which have been stabilized by the chemical-physical environmental conditions and preserved for hundreds of years. The whole IR spectrum of the tissues reveals traces of these " age-inhibitor " processes: 1) the water OH-stretching band (~3400 cm-1) features are indicative of the twofold role of the dehydration process, as a result of low temperatures and dry air, at the same time responsible for the protein structure modifications and determining the preservation; 2) conformational features of the proteins can be extracted by monitoring Amide I and Amide II bands (1500-1700 cm-1); 3) in the glucid specific spectral range (950-1150 cm-1), an increase was measured in the glucid/protein ratio, a spectroscopic marker for the AGE compounds formation as a consequence of the collagen binding to sugars in tissues [2]; 4) the amount of adipocere formation (2916-2849 cm-1 , 1700 cm-1) was correlated with the position of the remains in the pile of the corpses. The bone diagenesis was monitored by means of the mineralization parameters. SEM measurements were carried out with the purpose of a morphological characterization of the tissues, in comparison with the modern ones. SEM images were acquired with Zeiss Supra40-high resolution apparatus using low beams energies. Mummified collagen fibers and collagen network are shown in the skin and compact bones reveal a lot of well preserved ultrastructural features such as Harvesian canals [3]. Septate hyphae and spores, characteristic of a fungal colonization were identified, as well as a lot of burrowing insects, such as Dermestidae, commonly referred to as skin beetles, which feed on dry animal and their predators, staphilinides [4].
Bone is a composite tissue formed by a protein fraction, mainly consisting of collagen (type I), ... more Bone is a composite tissue formed by a protein fraction, mainly consisting of collagen (type I), and by a mineral component. It is characterized by a complex metabolism and the postmortem changes are not yet completely clarified. With the aim to investigate such modifications, three archaeological bones were studied: 1) metacarpus from Ovis aries (V millennium B. C.), 2) femur from Sus domesticus (3000-2800 B. C.), both collected from a site in East Anatolia, and c) animal bone fragment (VI-VII century AD), taken in Friuli, Italy. They were studied in comparison with a modern bone sample from beef tibia, by using Fourier Transform InfraRed (FTIR) spectroscopy. Collagen, extracted from the ancient remains by following a biochemical cold procedure to avoid polypeptide thermal denaturation, was analyzed in comparison with rat tail collagen, by FTIR, Circular Dichroism and Fluorescence spectroscopies. The results indicated a quite good preservation state of the sample mineral fraction. ...
A naturally mummified body was found in the basement of an ancient mansion in Bologna in the earl... more A naturally mummified body was found in the basement of an ancient mansion in Bologna in the early twentieth century. The remain is currently stored in the museum Centre of the Forensic Medicine section of the University of Bologna. The skeletal and soft tissues of the fortuitous recovery are all green colored but a leg. The remains were therefore identified as the \u201cgreen mummy\u201d. The \u201cgreen mummy\u201d is the body of a teenager (11 -14) as gathered from both the ossification and the teeth (fig. 1A-B). The the body posture, displaying the neck bent ahead on the chest and the legs folded back, suggested hints to hypothesize that the body could have been pushed and pressed in a copper box or urn
In the substantia nigra of human brain, neuromelanin (NM) released by degenerating neurons can ac... more In the substantia nigra of human brain, neuromelanin (NM) released by degenerating neurons can activate microglia with consequent neurodegeneration, typical of Parkinson's disease (PD). Synthetic analogues of NM were prepared to develop a PD model reproducing the neuropathological conditions of the disease. Soluble melanin-protein conjugates were obtained by melanization of fibrillated β-lactoglobulin (fLG). The melanic portion of the conjugates contains either eumelanic (EufLG) or mixed eumelanic/pheomelanic composition (PheofLG), the latter better simulating natural NMs. In addition, the conjugates can be loaded with controlled amounts of iron. Upon melanization, PheofLG-Fe conjugates maintain the amyloid cross-β protein core as the only structurally organized element, similarly to human NMs. The similarity in composition and structural organization with the natural pigment is reflected by the ability of synthetic NMs to activate microglia, showing potential of the novel conjugates to model NM induced neuroinflammation. Thus, synthetic NM/microglia constitute a new model to develop anti-Parkinson drugs.
Thermally stimulated depolarization currents technique has been employed to investigate the confo... more Thermally stimulated depolarization currents technique has been employed to investigate the conformation of hen egg white lysozyme in native and amyloid form, in the state of powder at very low hydration level. The technique, able to detect the current generated by thermally activated reorientation of water dipoles previously oriented by an electric field, exploits H2O dipoles, belonging to the solvation shell, as a probe to gain information on the protein conformation.Large differences are detected between the TSDC spectra related to the two different protein conformations, for what concerns the number and position of the main peaks, the native form displaying two peaks, atTM=175 K and atTM=297 K, and the amyloid one, only one at intermediate temperature (TM=235 K). The spectra have been compared with those monitored for poly-L-lysine (MW 80400), as received and prepared in different ways, i.e.α-helix,β-sheet, and coil conformation, respectively. The poly-L-lysine spectra show spec...
Journal of Biological Research - Bollettino della Società Italiana di Biologia Sperimentale, 2014
Some dynastic and pre-dynastic Egyptian mummies from the Giovanni Marro Museum of Anthropology an... more Some dynastic and pre-dynastic Egyptian mummies from the Giovanni Marro Museum of Anthropology and Ethnography, University of Turin, Italy have been studied by means of the combined approach of both Fourier transform infrared spectroscopy and histological analysis, with the aim of investigating the preservation state of the skin of ancient archaeological remains, as a consequence of the differences between the two kinds of mummification processes, <em>i.e.</em> natural and by means of embalming substances. The results suggest that the balms used in the dynastic mummies embalming process really could have played an important role in the prevention of corpse deterioration.
ABSTRACT The role of water in lipases, a class of proteins endowed with a large external hydropho... more ABSTRACT The role of water in lipases, a class of proteins endowed with a large external hydrophobic surface, is not yet fully understood. To analyse the water-related structural properties and the possible implications for the protein functionality, three experimental techniques such as water sorption isotherms, thermally stimulated depolarization currents (TSDCs), and Fourier transform infrared spectroscopy were applied to pellets and/or films of lipase from Candida lipolytica, prepared at very low hydration degrees h, ranging between 0.003 and 0.457 gwater/gprotein. Two main broad TSDC bands (a weak one peaking at T160 K and a strong one at T260 K) were detected. The peak amplitudes and positions critically depend not only on the water content, but also on the previous hydration history of the sample. FTIR spectra monitored: (1) the amplitude and position changes of the characteristic optical absorption bands (amide A, B, I, and II) as a function of the humidity level, (2) the presence of a considerable amount of β-sheet structure at high hydration degrees, and (3) a conformational transition induced by drastic dehydration treatments. Complementary sorption isotherms, performed by means of a gravimetric method, showed a marked hysteresis in the lipase-aqueous solvent interaction. The whole set of results provides a model for the initial steps of the lipase hydration kinetics. At h = 0.009, 13 water molecules are buried in the macromolecule, probably bound to the peptidic backbone. At h = 0.037 all polar and charged free groups are hydrated. At higher h a solution phase begins, and at h = 0.457 about 660 water molecules are accommodated around the protein, giving rise to three to four complete layer coverages.
The skin is a tissue composed of different layers. Each of them carries out a specific function. ... more The skin is a tissue composed of different layers. Each of them carries out a specific function. Epidermis, mainly constituted of keratinized cells, guarantees protection from dehydration and pathogen agents whilst dermis, composed in particular of collagen fibers provides resistance to tensile strength and compression. Analytical technique were more often applied to archaeological remains to characterize the constituting materials and their state of preservation. The knowledge of the modification mechanisms of the skin during time represents a fundamental condition for setting defined protocols of museum conservation of a particular class of archaeological remains: Mummies. The skin of some Egyptian mummies, natural and embalmed, from the collection of the Museum of Anthropology 87th SIBS National Congress on Peoples, Environment, Health | Turin, Italy, 5-6 December 2014 and Ethnography G. Marro of the University of Turin and of some natural mummified remains from Roccapelago were ...
ABSTRACT Measurements of Rayleigh scattering of Mössbauer radiation (RSMR) have been performed on... more ABSTRACT Measurements of Rayleigh scattering of Mössbauer radiation (RSMR) have been performed on synthetic L-Dopa melanin as a function of the scattering vector, Q, and temperature, T, and are compared with the results of X-ray diffraction analyses. The data obtained allow us to derive a radial distribution function for the atomic positions not affected by the dynamic disorder and determined only by the distribution of equilibrium interatomic distances. The mean-square atomic displacements, , derived from the RSMR measurements, evidence a strong anisotropy of the atomic vibrations: even at room temperature, reaches fairly high values for off-plane displacements, as compared with those for motions within the planes of the structure. A connection is suggested between the observed dynamics and the biological screening action of melanins.
The preservation status of some Egyptian embalmed heads stored in the Museum of Anthropology and ... more The preservation status of some Egyptian embalmed heads stored in the Museum of Anthropology and Ethnography of the University of Turin has been investigated by means of Fourier Transform InfraRed (FT-IR) absorption spectroscopy and microreflectance. Such non-destructive techniques are in fact suitable to study the biochemical composition and the degradation level of the remains in order to devise modern conservation procedures. Minute fragments (1.0-1.5 mg) of skin from seven embalmed heads and from one naturally mummified (pre-Dynastic period) have been investigated by IR absorption measurements in the 250–4000 cm-1 wavenumber range as pellets with KBr. The sample preservation status was evaluated by comparison with the spectrum of modern skin sample on the base of position and shape of the characteristic proteins and lipids bands. Different deterioration degrees were observed. The occurrence in the spectra of some features not related to the biological nature of the samples has been attributed to embalming chemicals and investigated by means of IR microscopy. Microreflectance measurements were performed with a resolution of 1 cm-1 from sampling areas as small as 0.4 x 0.4 mm. This preliminary report shows how spectroscopic micro-sampling techniques can be exploited to characterise ancient anthropological samples and to provide different information on the preservation status of the specimens and cultural treatments of the bodies in antiquity.
Thermally stimulated depolarization currents (TSDCs) and Fourier transform infrared (FTIR) spectr... more Thermally stimulated depolarization currents (TSDCs) and Fourier transform infrared (FTIR) spectroscopies were employed to investigate the state of water incorporated in a model DMPC (dimyristoyl-phosphatidylcholine) membrane. The lipid multilayers, highly inhomogeneous from the dielectric point of view, originate complex TSDC spectra critically dependent on the sample water content and thermal history. Different temperature ranges were chosen to polarize the sample, i.e. 100–300 K (type I) and 100–285 K (type II). The purpose of the latter choice was to avoid any sample heating above the DMPC phase transition temperature (295 K) along the sample polarization. According to the results, water in a fully hydrated system (a w = 0.92) (1) is ordered around the hydrophilic head molecular groups, (2) is layered in the interbilayer space and (3) penetrates among the hydrocarbon chains. It can assume different local structural configurations depending on the lipid packing. Irreversible conformational transitions in the lipid array system were monitored as a consequence of different dehydration treatments. FTIR absorption measurements were performed to study the water sorption kinetics into a DMPC thin film. The water related OH band was decomposed into three components, describing three water states, with different propensity to the H-bond formation. The changes of the lipid characteristic groups (CH 2 /CH 3 , PO − 2 and C=O) absorption bands as a function of increasing hydration level were monitored and discussed. (Some figures may appear in colour only in the online journal)
Some dynastic and pre-dynastic Egyptian mummies from the Giovanni Marro Museum of Anthropology an... more Some dynastic and pre-dynastic Egyptian mummies from the Giovanni Marro Museum of Anthropology and Ethnography, University of Turin, Italy have been studied by means of the combined approach of both Fourier transform infrared spectroscopy and histological analysis , with the aim of investigating the preservation state of the skin of ancient archaeological remains, as a consequence of the differences between the two kinds of mummification processes, i.e. natural and by means of embalming substances. The results suggest that the balms used in the dynastic mummies embalming process really could have played an important role in the prevention of corpse deterioration.
In the substantia nigra of human brain, neuromelanin (NM) released by degenerating neurons can ac... more In the substantia nigra of human brain, neuromelanin (NM) released by degenerating neurons can activate microglia with consequent neurodegeneration, typical of Parkinson's disease (PD). Synthetic analogues of NM were prepared to develop a PD model reproducing the neuropathological conditions of the disease. Soluble melanin−protein conjugates were obtained by melanization of fibrillated β-lactoglobulin (fLG). The melanic portion of the conjugates contains either eumelanic (EufLG) or mixed eumelanic/pheomelanic composition (PheofLG), the latter better simulating natural NMs. In addition, the conjugates can be loaded with controlled amounts of iron. Upon melanization, PheofLG−Fe conjugates maintain the amyloid cross-β protein core as the only structurally organized element, similarly to human NMs. The similarity in composition and structural organization with the natural pigment is reflected by the ability of synthetic NMs to activate microglia, showing potential of the novel conjugates to model NM induced neuroinflammation. Thus, synthetic NM/microglia constitute a new model to develop anti-Parkinson drugs.
Although it has long been known that the peculiar electronic–ionic conductor behavior of eumelani... more Although it has long been known that the peculiar electronic–ionic conductor behavior of eumelanin is critically dependent on hydration, the detailed mechanisms by which water–polymer interactions control and affect the conduction properties have remained largely obscure. In this paper, we report a remarkable anisotropy and giant polarization effect in a synthetic eumelanin (TEGMe) chemically functionalized with hydrophilic TEG residues. FT-IR analyses of water sorption isotherms and AC measurements were consistent with a microporous structure binding or hosting mainly isolated water molecules. In contrast, similar experiments on a commercial synthetic eumelanin (AMe) used as a reference were suggestive of a bulk macroporous scaffold binding or hosting liquid water. These data disclosed for the first time the differential impact on eumelanin conductivity of vapor, liquid and ice-like forms of water adsorbed onto or embedded into the polymer layer. It is thus demonstrated, for the first time, that hydration controls the conduction properties of eumelanin in a more complex manner than is commonly believed, involving, besides the reported semiquinone comproportionation equilibria, the mode of interaction of water molecules as governed by both the chemical and morphological features of the polymer.
Between 2009 and 2011, during restorative works at the Church of Roccapelago (province of Modena,... more Between 2009 and 2011, during restorative works at the Church of Roccapelago (province of Modena, Italy) a remote mountain village, hundreds of bodies, some of them mummified because of natural processes, were discovered in a forgotten crypt in use from the mid-16th to the 18th centuries. Mummification processes occurred unevenly, with bodies partially skeletonized and bodies only partly articulated [1]. 12 of these mummies, the most complete and representative, were studied with non-invasive methods and replaced in the crypt, set up as a museum (Fig. 1). The objects of this study are fragments of a variety of tissues taken from the mummies of the US 23 of the crypt of Roccapelago: skin pieces taken from different parts of the body, muscle, tendon, lung, bone, hair… The tissues were analyzed by means of FTIR spectroscopy applied in the transmission geometry, on samples obtained by mixing small quantities of the samples with pulverized KBr. In the IR spectrum of the investigated tissues the main absorption bands of the biological components such as proteins, lipids, nucleic acids, and carbohydrates were detected and characterized. The biochemical modifications recorded reveal a partial alteration of the ancient tissues which have been stabilized by the chemical-physical environmental conditions and preserved for hundreds of years. The whole IR spectrum of the tissues reveals traces of these &quot; age-inhibitor &quot; processes: 1) the water OH-stretching band (~3400 cm-1) features are indicative of the twofold role of the dehydration process, as a result of low temperatures and dry air, at the same time responsible for the protein structure modifications and determining the preservation; 2) conformational features of the proteins can be extracted by monitoring Amide I and Amide II bands (1500-1700 cm-1); 3) in the glucid specific spectral range (950-1150 cm-1), an increase was measured in the glucid/protein ratio, a spectroscopic marker for the AGE compounds formation as a consequence of the collagen binding to sugars in tissues [2]; 4) the amount of adipocere formation (2916-2849 cm-1 , 1700 cm-1) was correlated with the position of the remains in the pile of the corpses. The bone diagenesis was monitored by means of the mineralization parameters. SEM measurements were carried out with the purpose of a morphological characterization of the tissues, in comparison with the modern ones. SEM images were acquired with Zeiss Supra40-high resolution apparatus using low beams energies. Mummified collagen fibers and collagen network are shown in the skin and compact bones reveal a lot of well preserved ultrastructural features such as Harvesian canals [3]. Septate hyphae and spores, characteristic of a fungal colonization were identified, as well as a lot of burrowing insects, such as Dermestidae, commonly referred to as skin beetles, which feed on dry animal and their predators, staphilinides [4].
Bone is a composite tissue formed by a protein fraction, mainly consisting of collagen (type I), ... more Bone is a composite tissue formed by a protein fraction, mainly consisting of collagen (type I), and by a mineral component. It is characterized by a complex metabolism and the postmortem changes are not yet completely clarified. With the aim to investigate such modifications, three archaeological bones were studied: 1) metacarpus from Ovis aries (V millennium B. C.), 2) femur from Sus domesticus (3000-2800 B. C.), both collected from a site in East Anatolia, and c) animal bone fragment (VI-VII century AD), taken in Friuli, Italy. They were studied in comparison with a modern bone sample from beef tibia, by using Fourier Transform InfraRed (FTIR) spectroscopy. Collagen, extracted from the ancient remains by following a biochemical cold procedure to avoid polypeptide thermal denaturation, was analyzed in comparison with rat tail collagen, by FTIR, Circular Dichroism and Fluorescence spectroscopies. The results indicated a quite good preservation state of the sample mineral fraction. ...
A naturally mummified body was found in the basement of an ancient mansion in Bologna in the earl... more A naturally mummified body was found in the basement of an ancient mansion in Bologna in the early twentieth century. The remain is currently stored in the museum Centre of the Forensic Medicine section of the University of Bologna. The skeletal and soft tissues of the fortuitous recovery are all green colored but a leg. The remains were therefore identified as the \u201cgreen mummy\u201d. The \u201cgreen mummy\u201d is the body of a teenager (11 -14) as gathered from both the ossification and the teeth (fig. 1A-B). The the body posture, displaying the neck bent ahead on the chest and the legs folded back, suggested hints to hypothesize that the body could have been pushed and pressed in a copper box or urn
In the substantia nigra of human brain, neuromelanin (NM) released by degenerating neurons can ac... more In the substantia nigra of human brain, neuromelanin (NM) released by degenerating neurons can activate microglia with consequent neurodegeneration, typical of Parkinson&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39;s disease (PD). Synthetic analogues of NM were prepared to develop a PD model reproducing the neuropathological conditions of the disease. Soluble melanin-protein conjugates were obtained by melanization of fibrillated β-lactoglobulin (fLG). The melanic portion of the conjugates contains either eumelanic (EufLG) or mixed eumelanic/pheomelanic composition (PheofLG), the latter better simulating natural NMs. In addition, the conjugates can be loaded with controlled amounts of iron. Upon melanization, PheofLG-Fe conjugates maintain the amyloid cross-β protein core as the only structurally organized element, similarly to human NMs. The similarity in composition and structural organization with the natural pigment is reflected by the ability of synthetic NMs to activate microglia, showing potential of the novel conjugates to model NM induced neuroinflammation. Thus, synthetic NM/microglia constitute a new model to develop anti-Parkinson drugs.
Thermally stimulated depolarization currents technique has been employed to investigate the confo... more Thermally stimulated depolarization currents technique has been employed to investigate the conformation of hen egg white lysozyme in native and amyloid form, in the state of powder at very low hydration level. The technique, able to detect the current generated by thermally activated reorientation of water dipoles previously oriented by an electric field, exploits H2O dipoles, belonging to the solvation shell, as a probe to gain information on the protein conformation.Large differences are detected between the TSDC spectra related to the two different protein conformations, for what concerns the number and position of the main peaks, the native form displaying two peaks, atTM=175 K and atTM=297 K, and the amyloid one, only one at intermediate temperature (TM=235 K). The spectra have been compared with those monitored for poly-L-lysine (MW 80400), as received and prepared in different ways, i.e.α-helix,β-sheet, and coil conformation, respectively. The poly-L-lysine spectra show spec...
Journal of Biological Research - Bollettino della Società Italiana di Biologia Sperimentale, 2014
Some dynastic and pre-dynastic Egyptian mummies from the Giovanni Marro Museum of Anthropology an... more Some dynastic and pre-dynastic Egyptian mummies from the Giovanni Marro Museum of Anthropology and Ethnography, University of Turin, Italy have been studied by means of the combined approach of both Fourier transform infrared spectroscopy and histological analysis, with the aim of investigating the preservation state of the skin of ancient archaeological remains, as a consequence of the differences between the two kinds of mummification processes, <em>i.e.</em> natural and by means of embalming substances. The results suggest that the balms used in the dynastic mummies embalming process really could have played an important role in the prevention of corpse deterioration.
ABSTRACT The role of water in lipases, a class of proteins endowed with a large external hydropho... more ABSTRACT The role of water in lipases, a class of proteins endowed with a large external hydrophobic surface, is not yet fully understood. To analyse the water-related structural properties and the possible implications for the protein functionality, three experimental techniques such as water sorption isotherms, thermally stimulated depolarization currents (TSDCs), and Fourier transform infrared spectroscopy were applied to pellets and/or films of lipase from Candida lipolytica, prepared at very low hydration degrees h, ranging between 0.003 and 0.457 gwater/gprotein. Two main broad TSDC bands (a weak one peaking at T160 K and a strong one at T260 K) were detected. The peak amplitudes and positions critically depend not only on the water content, but also on the previous hydration history of the sample. FTIR spectra monitored: (1) the amplitude and position changes of the characteristic optical absorption bands (amide A, B, I, and II) as a function of the humidity level, (2) the presence of a considerable amount of β-sheet structure at high hydration degrees, and (3) a conformational transition induced by drastic dehydration treatments. Complementary sorption isotherms, performed by means of a gravimetric method, showed a marked hysteresis in the lipase-aqueous solvent interaction. The whole set of results provides a model for the initial steps of the lipase hydration kinetics. At h = 0.009, 13 water molecules are buried in the macromolecule, probably bound to the peptidic backbone. At h = 0.037 all polar and charged free groups are hydrated. At higher h a solution phase begins, and at h = 0.457 about 660 water molecules are accommodated around the protein, giving rise to three to four complete layer coverages.
The skin is a tissue composed of different layers. Each of them carries out a specific function. ... more The skin is a tissue composed of different layers. Each of them carries out a specific function. Epidermis, mainly constituted of keratinized cells, guarantees protection from dehydration and pathogen agents whilst dermis, composed in particular of collagen fibers provides resistance to tensile strength and compression. Analytical technique were more often applied to archaeological remains to characterize the constituting materials and their state of preservation. The knowledge of the modification mechanisms of the skin during time represents a fundamental condition for setting defined protocols of museum conservation of a particular class of archaeological remains: Mummies. The skin of some Egyptian mummies, natural and embalmed, from the collection of the Museum of Anthropology 87th SIBS National Congress on Peoples, Environment, Health | Turin, Italy, 5-6 December 2014 and Ethnography G. Marro of the University of Turin and of some natural mummified remains from Roccapelago were ...
ABSTRACT Measurements of Rayleigh scattering of Mössbauer radiation (RSMR) have been performed on... more ABSTRACT Measurements of Rayleigh scattering of Mössbauer radiation (RSMR) have been performed on synthetic L-Dopa melanin as a function of the scattering vector, Q, and temperature, T, and are compared with the results of X-ray diffraction analyses. The data obtained allow us to derive a radial distribution function for the atomic positions not affected by the dynamic disorder and determined only by the distribution of equilibrium interatomic distances. The mean-square atomic displacements, , derived from the RSMR measurements, evidence a strong anisotropy of the atomic vibrations: even at room temperature, reaches fairly high values for off-plane displacements, as compared with those for motions within the planes of the structure. A connection is suggested between the observed dynamics and the biological screening action of melanins.
The preservation status of some Egyptian embalmed heads stored in the Museum of Anthropology and ... more The preservation status of some Egyptian embalmed heads stored in the Museum of Anthropology and Ethnography of the University of Turin has been investigated by means of Fourier Transform InfraRed (FT-IR) absorption spectroscopy and microreflectance. Such non-destructive techniques are in fact suitable to study the biochemical composition and the degradation level of the remains in order to devise modern conservation procedures. Minute fragments (1.0-1.5 mg) of skin from seven embalmed heads and from one naturally mummified (pre-Dynastic period) have been investigated by IR absorption measurements in the 250–4000 cm-1 wavenumber range as pellets with KBr. The sample preservation status was evaluated by comparison with the spectrum of modern skin sample on the base of position and shape of the characteristic proteins and lipids bands. Different deterioration degrees were observed. The occurrence in the spectra of some features not related to the biological nature of the samples has been attributed to embalming chemicals and investigated by means of IR microscopy. Microreflectance measurements were performed with a resolution of 1 cm-1 from sampling areas as small as 0.4 x 0.4 mm. This preliminary report shows how spectroscopic micro-sampling techniques can be exploited to characterise ancient anthropological samples and to provide different information on the preservation status of the specimens and cultural treatments of the bodies in antiquity.
Thermally stimulated depolarization currents (TSDCs) and Fourier transform infrared (FTIR) spectr... more Thermally stimulated depolarization currents (TSDCs) and Fourier transform infrared (FTIR) spectroscopies were employed to investigate the state of water incorporated in a model DMPC (dimyristoyl-phosphatidylcholine) membrane. The lipid multilayers, highly inhomogeneous from the dielectric point of view, originate complex TSDC spectra critically dependent on the sample water content and thermal history. Different temperature ranges were chosen to polarize the sample, i.e. 100–300 K (type I) and 100–285 K (type II). The purpose of the latter choice was to avoid any sample heating above the DMPC phase transition temperature (295 K) along the sample polarization. According to the results, water in a fully hydrated system (a w = 0.92) (1) is ordered around the hydrophilic head molecular groups, (2) is layered in the interbilayer space and (3) penetrates among the hydrocarbon chains. It can assume different local structural configurations depending on the lipid packing. Irreversible conformational transitions in the lipid array system were monitored as a consequence of different dehydration treatments. FTIR absorption measurements were performed to study the water sorption kinetics into a DMPC thin film. The water related OH band was decomposed into three components, describing three water states, with different propensity to the H-bond formation. The changes of the lipid characteristic groups (CH 2 /CH 3 , PO − 2 and C=O) absorption bands as a function of increasing hydration level were monitored and discussed. (Some figures may appear in colour only in the online journal)
Some dynastic and pre-dynastic Egyptian mummies from the Giovanni Marro Museum of Anthropology an... more Some dynastic and pre-dynastic Egyptian mummies from the Giovanni Marro Museum of Anthropology and Ethnography, University of Turin, Italy have been studied by means of the combined approach of both Fourier transform infrared spectroscopy and histological analysis , with the aim of investigating the preservation state of the skin of ancient archaeological remains, as a consequence of the differences between the two kinds of mummification processes, i.e. natural and by means of embalming substances. The results suggest that the balms used in the dynastic mummies embalming process really could have played an important role in the prevention of corpse deterioration.
In the substantia nigra of human brain, neuromelanin (NM) released by degenerating neurons can ac... more In the substantia nigra of human brain, neuromelanin (NM) released by degenerating neurons can activate microglia with consequent neurodegeneration, typical of Parkinson's disease (PD). Synthetic analogues of NM were prepared to develop a PD model reproducing the neuropathological conditions of the disease. Soluble melanin−protein conjugates were obtained by melanization of fibrillated β-lactoglobulin (fLG). The melanic portion of the conjugates contains either eumelanic (EufLG) or mixed eumelanic/pheomelanic composition (PheofLG), the latter better simulating natural NMs. In addition, the conjugates can be loaded with controlled amounts of iron. Upon melanization, PheofLG−Fe conjugates maintain the amyloid cross-β protein core as the only structurally organized element, similarly to human NMs. The similarity in composition and structural organization with the natural pigment is reflected by the ability of synthetic NMs to activate microglia, showing potential of the novel conjugates to model NM induced neuroinflammation. Thus, synthetic NM/microglia constitute a new model to develop anti-Parkinson drugs.
Although it has long been known that the peculiar electronic–ionic conductor behavior of eumelani... more Although it has long been known that the peculiar electronic–ionic conductor behavior of eumelanin is critically dependent on hydration, the detailed mechanisms by which water–polymer interactions control and affect the conduction properties have remained largely obscure. In this paper, we report a remarkable anisotropy and giant polarization effect in a synthetic eumelanin (TEGMe) chemically functionalized with hydrophilic TEG residues. FT-IR analyses of water sorption isotherms and AC measurements were consistent with a microporous structure binding or hosting mainly isolated water molecules. In contrast, similar experiments on a commercial synthetic eumelanin (AMe) used as a reference were suggestive of a bulk macroporous scaffold binding or hosting liquid water. These data disclosed for the first time the differential impact on eumelanin conductivity of vapor, liquid and ice-like forms of water adsorbed onto or embedded into the polymer layer. It is thus demonstrated, for the first time, that hydration controls the conduction properties of eumelanin in a more complex manner than is commonly believed, involving, besides the reported semiquinone comproportionation equilibria, the mode of interaction of water molecules as governed by both the chemical and morphological features of the polymer.
Negli anni recenti la decifrazione dei reperti mummificati si è avvalsa anche dell’impiego di tec... more Negli anni recenti la decifrazione dei reperti mummificati si è avvalsa anche dell’impiego di tecniche fisiche che tradizionalmente appartengono ad un ambito estraneo all’archeologia, ma che, applicate allo studio delle mummie e avendo quindi per oggetto il corpo umano, si avvicinano alla vita. Con l’impiego di queste tecniche una mummia diventa “oggetto di ricerca” e archivio di informazioni.
Fourier Transform Infrared (FT-IR) spectroscopy and microspectroscopy were used in order to gain ... more Fourier Transform Infrared (FT-IR) spectroscopy and microspectroscopy were used in order to gain insights into the preservation state of the skin of two dynastic Egyptian embalmed heads (VI – XI Dynasty) and one Predynastic mummy, coming from the necropoles of Asiut and Gebelein (Upper Egypt), and stored in the Museum of Anthropology and Ethnography of the University of Turin. The preservation state was inferred from the skin biochemical composition, in particular from the secondary structure of proteins. The skin protein secondary structure was investigated by studying position and shape of the Amide I band analyzed by means of self-deconvolution techniques. The increase in the -sheet relative amount in the protein conformation of the mummified tissues with respect to the modern skin, was correlated with ageing processes of collagen and keratins, the most abundant proteins in the skin. The steps of the degradation processes are hypothesized and described and the differences in the recorded degradation state were ascribed to the diverse mummification procedures undergone by the studied human remains. Other non-skin derived features in the IR microspectra of embalmed specimens were detected and identified either as embalmed materials or microbial attack traces.
The interaction between biological macromolecules (proteins, nucleic acids, lipids and other biom... more The interaction between biological macromolecules (proteins, nucleic acids, lipids and other biomolecules in the cell) and environmental water is an important determining factor in their conformational properties, stability and function. The hydration processes of biopolymers have been extensively studied in the past 20 years with reference to a considerable variety of models and concepts. In all recent works, a distinction is made between intracellular water that maintains the ordinary liquid state (bulk water) and water ordered in extended hydrogen‐bonded lattices at the surface and structured in the internal grooves of macromolecules (hydration water) in dependence on the chemical properties of the macromolecule surface. FTIR spectroscopy has been implemented in this field both for the sensitivity in the conformational analysis of biological macromol‐ ecules and the reliability in the investigation of the water network. A perturbation tech‐ nique such as dehydration‐rehydration treatment modifies the macromolecule structure and water distribution. It was applied to two structurally different proteins: lysozyme, a globular (α + β) protein and collagen, a fibrous protein characterized by the triple helix structure. Submitted to the treatment both of them display irreversible conformational changes.
The work will discuss the materials employed in the mummification of some Egyptian Dynastic embal... more The work will discuss the materials employed in the mummification of some Egyptian Dynastic embalmed heads (VI – XI Dynasty) and is the summary of a lot of studies performed in this framework in the last two years. The samples are skin fragments removed from mummified heads belonging to the " Giovanni Marro " collection, developed by Professor G. Marro between 1907 and 1913, at the necropolises of Asiut (the old Lycopolis), 380 km south of Cairo, and of Gebelein 28 km south of Luxor (the ancient Thebes), during three of the archaeological campaigns of the Italian Archaeological Mission. The collection is curated at the Museum of Anthropology and Ethnography of the University of Turin. The present work takes part in the number of activities promoted by the Museum for management and conservation of the stored ancient remains [1]. Several physical techniques were employed to detect and analyze the traces of the embalming materials on the mummified remains. FTIR spectroscopy was applied on samples prepared as KBr pellets and allowed to gain information both on the embalming substances spread on the skin and on the preservation state of the skin from the analysis of the characteristic bands of the cutaneous tissue. Micro-FTIR spectroscopy (beam light area about 0.4×0.4 mm 2) was employed to identify the chemical nature of the materials on the skin surface and to measure the embalming substance penetration in the skin by focusing the IR beam on tissue layers at different depth. The results were compared with the histological measurements. Skin fragments were Mayer's hemalum and eosine stained and revealed some brownish-yellow bands inserted among the bluish collagen fibers which may be attributed to the embalming substances soaked through the skin surface. ATR spectroscopy was applied to water and ethanol extracts of one of the embalmed skin samples. Several embalming substances were tested by matching the IR spectra against a library of diagnostic markers and the excellent superposition of the propolis spectrum supports the hypothesis that one of the embalming substances could have been beeswax (Fig. 1) [2], [3]. Finally, SEM images of some skin fragments showing Natron encrustations will be shown, supplied by XRD analyses.
Between 2009 and 2011, during restorative works at the Church of Roccapelago (province of Modena,... more Between 2009 and 2011, during restorative works at the Church of Roccapelago (province of Modena, Italy) a remote mountain village, hundreds of bodies, some of them mummified because of natural processes, were discovered in a forgotten crypt in use from the mid-16th to the 18th centuries. Mummification processes occurred unevenly, with bodies partially skeletonized and bodies only partly articulated [1]. 12 of these mummies, the most complete and representative, were studied with non-invasive methods and replaced in the crypt, set up as a museum (Fig. 1). The objects of this study are fragments of a variety of tissues taken from the mummies of the US 23 of the crypt of Roccapelago: skin pieces taken from different parts of the body, muscle, tendon, lung, bone, hair… The tissues were analyzed by means of FTIR spectroscopy applied in the transmission geometry, on samples obtained by mixing small quantities of the samples with pulverized KBr. In the IR spectrum of the investigated tissues the main absorption bands of the biological components such as proteins, lipids, nucleic acids, and carbohydrates were detected and characterized. The biochemical modifications recorded reveal a partial alteration of the ancient tissues which have been stabilized by the chemical-physical environmental conditions and preserved for hundreds of years. The whole IR spectrum of the tissues reveals traces of these " age-inhibitor " processes: 1) the water OH-stretching band (~3400 cm-1) features are indicative of the twofold role of the dehydration process, as a result of low temperatures and dry air, at the same time responsible for the protein structure modifications and determining the preservation; 2) conformational features of the proteins can be extracted by monitoring Amide I and Amide II bands (1500-1700 cm-1); 3) in the glucid specific spectral range (950-1150 cm-1), an increase was measured in the glucid/protein ratio, a spectroscopic marker for the AGE compounds formation as a consequence of the collagen binding to sugars in tissues [2]; 4) the amount of adipocere formation (2916-2849 cm-1 , 1700 cm-1) was correlated with the position of the remains in the pile of the corpses. The bone diagenesis was monitored by means of the mineralization parameters. SEM measurements were carried out with the purpose of a morphological characterization of the tissues, in comparison with the modern ones. SEM images were acquired with Zeiss Supra40-high resolution apparatus using low beams energies. Mummified collagen fibers and collagen network are shown in the skin and compact bones reveal a lot of well preserved ultrastructural features such as Harvesian canals [3]. Septate hyphae and spores, characteristic of a fungal colonization were identified, as well as a lot of burrowing insects, such as Dermestidae, commonly referred to as skin beetles, which feed on dry animal and their predators, staphilinides [4].
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Papers by Maria Grazia Bridelli