Glomerulopathies with nephrotic syndrome that are resistant to therapy often progress to end-stage chronic kidney disease (CKD) and require timely and accurate diagnosis. Targeted quantitative urine proteome analysis by mass spectrometry... more
Glomerulopathies with nephrotic syndrome that are resistant to therapy often progress to end-stage chronic kidney disease (CKD) and require timely and accurate diagnosis. Targeted quantitative urine proteome analysis by mass spectrometry (MS) with multiple-reaction monitoring (MRM) is a promising tool for early CKD diagnostics that could replace the invasive biopsy procedure. However, there are few studies regarding the development of highly multiplexed MRM assays for urine proteome analysis, and the two MRM assays for urine proteomics described so far demonstrate very low consistency. Thus, the further development of targeted urine proteome assays for CKD is actual task. Herein, a BAK270 MRM assay previously validated for blood plasma protein analysis was adapted for urine-targeted proteomics. Because proteinuria associated with renal impairment is usually associated with an increased diversity of plasma proteins being present in urine, the use of this panel was appropriate. Anothe...
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The molecular mechanisms underlying cardiovascular complications after the SARS-CoV-2 infection remain unknown. The goal of our study was to analyze the features of blood coagulation, platelet aggregation, and plasma proteomics in... more
The molecular mechanisms underlying cardiovascular complications after the SARS-CoV-2 infection remain unknown. The goal of our study was to analyze the features of blood coagulation, platelet aggregation, and plasma proteomics in COVID-19 convalescents with AMI. The study included 66 AMI patients and 58 healthy volunteers. The groups were divided according to the anti-N IgG levels (AMI post-COVID (n = 44), AMI control (n = 22), control post-COVID (n = 31), and control (n = 27)). All participants underwent rotational thromboelastometry, thrombodynamics, impedance aggregometry, and blood plasma proteomics analysis. Both AMI groups of patients demonstrated higher values of clot growth rates, thrombus size and density, as well as the elevated levels of components of the complement system, proteins modifying the state of endothelium, acute-phase and procoagulant proteins. In comparison with AMI control, AMI post-COVID patients demonstrated decreased levels of proteins connected to infla...
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ABSTRACT The physicochemical conditions of the aqueous environment at the dawn of biological evolution were of key importance for abiogenic peptide synthesis. Recently, we have shown theoretical and experimental evidence for the unique... more
ABSTRACT The physicochemical conditions of the aqueous environment at the dawn of biological evolution were of key importance for abiogenic peptide synthesis. Recently, we have shown theoretical and experimental evidence for the unique role of potassium ions in the exponential acceleration of undirected peptide synthesis from L-glutamic acid. These data have confirmed our previous hypothesis that the first protocell emerged in a potassium rather than sodium-rich aqueous solution (seawater). The present work provides experimental data for an interpretation of concentration dependence and of optimal effective concentration of potassium and sodium ions in L-glutamic acid peptide formation.
Research Interests: Evolutionary Biology, Geology, Chemistry, Ecology, Potassium, and 4 morePeptide, Sodium, Aqueous Solution, and Protocell
In carrying out proteomic researches using mass-spectrometry there often arises a need to compare experimental data with each other (e.g. control of pathology, the labeled to unlabelled samples). If for peptide identification in different... more
In carrying out proteomic researches using mass-spectrometry there often arises a need to compare experimental data with each other (e.g. control of pathology, the labeled to unlabelled samples). If for peptide identification in different experiments one uses only their exact mass measurements and the retention time in the chromatographic column, difficulties with the identification of chromatographic peaks belonging to the same substances in different chromatograms come up (retention time normalization). Due to inevitable discrepancies in chromatographic conditions of experiments (replacement of chromatographic columns, small changes in mobile phase flow rate or solvent concentration) retention times of the same peptides will diverge from experiment to experiment. In this paper we offer a reliable method for selecting peaks from mass-chromatograms corresponding to the same peptides, which can later be used for retention time normalization (either linear or any other monotone functi...
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Proteomic studies with the use of mass spectrometry required comparison of different experimental data (for example, control with a pathology or labeled and unlabeled samples). Identification of chromatographic peaks of the same substance... more
Proteomic studies with the use of mass spectrometry required comparison of different experimental data (for example, control with a pathology or labeled and unlabeled samples). Identification of chromatographic peaks of the same substance in different chromatograms (time normalization of chromatograms) is complicated if peptides are identified in different experiments according only to their exactly evaluated masses and retention times on
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Resolving power of about 12,000 000 at m/z 675 has been achieved on low field homogeneity 4.7 T magnet using a dynamically harmonized Fourier transform ion cyclotron resonance (FT ICR) cell. Mass spectra of the fine structure of the... more
Resolving power of about 12,000 000 at m/z 675 has been achieved on low field homogeneity 4.7 T magnet using a dynamically harmonized Fourier transform ion cyclotron resonance (FT ICR) cell. Mass spectra of the fine structure of the isotopic distribution of a peptide were obtained and strong discrimination of small intensity peaks was observed in case of resonance excitation of the ions of the whole isotopic cluster to the same cyclotron radius. The absence of some peaks from the mass spectra of the fine structure was explained basing on results of computer simulations showing strong ion cloud interactions, which cause the coalescence of peaks with m/z close to that of the highest magnitude peak. The way to prevent peak discrimination is to excite ion clouds of different m/z to different cyclotron radii, which was demonstrated and investigated both experimentally and by computer simulations.
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The urine protein composition (proteome) of healthy human was analyzed using proteomic techniques to obtain data in physiological condition and after six months space flights. It was shown that after long duration space flights in... more
The urine protein composition (proteome) of healthy human was analyzed using proteomic techniques to obtain data in physiological condition and after six months space flights. It was shown that after long duration space flights in cosmonaut's urine reveals specific minor proteins which can be identified as proteins came from kidney and urinary tract.
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We report an approach to study volatile organic compounds based on thermal desorption combined with atmospheric pressure photo ionization. The approach allows the sequential evaporation of different fractions of the sample, which... more
We report an approach to study volatile organic compounds based on thermal desorption combined with atmospheric pressure photo ionization. The approach allows the sequential evaporation of different fractions of the sample, which simplifies the mass spectrum. We have applied the developed method for the detection of petroleum in vegetable oil. We have shown that in the negative mode, ions of fatty acids corresponding to vegetable oil dominates, while in the positive mode under relatively low temperature the light fraction of petroleum rapidly evaporates making it easy detectable.
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ABSTRACT
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ABSTRACT Transthyretin, one of the major blood proteins, displays a variety of posttranslational modifications, including those related to the development of grave diseases, such as Alzheimer’s disease, and familial amyloid... more
ABSTRACT Transthyretin, one of the major blood proteins, displays a variety of posttranslational modifications, including those related to the development of grave diseases, such as Alzheimer’s disease, and familial amyloid polyneuropathy. A combined analytical technique based on the use of two mass spectrometric approaches (bottom-up and top-down) has been developed in the present study to determine the role of the modified forms of transthyretin in the progression of Alzheimer’s disease. The high efficiency of this technique has been demonstrated for ten serum samples obtained from patients diagnosed with Alzheimer’s disease and healthy volunteers.
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Ion motion in a periodic radio frequency (RF) quadrupole electric field is analysed theoretically by the matrix method and direct trajectory calculation. General properties of the ion motion: stability condition, oscillation spectrum and... more
Ion motion in a periodic radio frequency (RF) quadrupole electric field is analysed theoretically by the matrix method and direct trajectory calculation. General properties of the ion motion: stability condition, oscillation spectrum and secular frequency are derived analytically from the elements of the transformation matrix. Stability diagrams for ion motion in the Paul ion trap are presented for rectangular waveforms with different duty cycles (duration of pulse over period). Calculation of the secular frequencies of the ion motion in the ion trap is performed for the first time. The relation of radial and axial secular frequencies along the RF scan line was found to be practically identical in both the square waveform and harmonic voltage cases. Pulse shape distortions, due to resistive-inductive-capacitive filtering in real devices, are considered. Stability diagrams of ion motion in the ion trap with distorted voltage waveforms are calculated. Distortion of the waveform is sho...
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The automatic processing of high-dimensional mass spectrometry data is required for the clinical implementation of ambient ionization molecular profiling methods. However, complex algorithms required for the analysis of peak-rich spectra... more
The automatic processing of high-dimensional mass spectrometry data is required for the clinical implementation of ambient ionization molecular profiling methods. However, complex algorithms required for the analysis of peak-rich spectra are sensitive to the quality of the input data. Therefore, an objective and quantitative indicator, insensitive to the conditions of the experiment, is currently in high demand for the automated treatment of mass spectrometric data. In this work, we demonstrate the utility of the Shapley value as an indicator of the quality of the individual mass spectrum in the classification task for human brain tumor tissue discrimination. The Shapley values are calculated on the training set of glioblastoma and nontumor pathological tissues spectra and used as feedback to create a random forest regression model to estimate the contributions for all spectra of each specimen. As a result, it is shown that the implementation of Shapley values significantly accelera...
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Mass spectrometry fingerprinting combined with multidimensional data analysis has been proposed in surgery to determine if a biopsy sample is a tumor. In the specific case of brain tumors, it is complicated to obtain control samples,... more
Mass spectrometry fingerprinting combined with multidimensional data analysis has been proposed in surgery to determine if a biopsy sample is a tumor. In the specific case of brain tumors, it is complicated to obtain control samples, leading to model overfitting due to unbalanced sample cohorts. Usually, classifiers are trained using a single measurement regime, most notably single ion polarity, but mass range and spectral resolution could also be varied. It is known that lipid groups differ significantly in their ability to produce positive or negative ions; hence, using only one polarity significantly restricts the chemical space available for sample discrimination purposes. In this work, we have developed an approach employing mass spectrometry data obtained by eight different regimes of measurement simultaneously. Regime-specific classifiers are trained, then a mixture of experts techniques based on voting or mean probability is used to aggregate predictions of all trained class...
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ABSTRACT Four mumijo samples originated from different mountain ranges were studied using size-exclusion chromatography (SEC), Fourier transform ion cyclotron resonance mass spectrometry (FTICR MS), and 1 H and 13 C NMR spectroscopy. All... more
ABSTRACT Four mumijo samples originated from different mountain ranges were studied using size-exclusion chromatography (SEC), Fourier transform ion cyclotron resonance mass spectrometry (FTICR MS), and 1 H and 13 C NMR spectroscopy. All the used analytical techniques demonstrated that the mumijo samples studied consist of a "high-molecular" fulvic-like and a low-molecular components. The second component is shown using FTICR MS and NMR methods to be predominantly a range of vegetative and animal metabolites.
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Preeclampsia (PE) is a multisystem disorder associated with pregnancy and its frequency varies from 5 to 20 percent of pregnancies. Although a number of preeclampsia studies have been carried out, there is no consensus about disease... more
Preeclampsia (PE) is a multisystem disorder associated with pregnancy and its frequency varies from 5 to 20 percent of pregnancies. Although a number of preeclampsia studies have been carried out, there is no consensus about disease etiology and pathogenesis so far. Peptides of SERPINA1 (α1-antitrypsin) in urine remain one of the most promising peptide markers of PE. In this study the diagnostic potential of urinary α1-antitrypsin peptides in PE was evaluated. The urinary peptidome composition of 79 pregnant women with preeclampsia (PE), chronic arterial hypertension (CAH), and a control group was investigated. Mann–Whitney U-test (p < 0.05) revealed seven PE specific SERPINA1 peptides demonstrating 52% sensitivity and 100% specificity. SERPINA1 in urine has been associated with the most severe forms of preeclampsia (p = 0.014), in terms of systolic hypertension (p = 0.01) and proteinuria (p = 0.006). According to Spearman correlation analysis, the normalized intensity of SERPINA...
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In this work, we demonstrate a new approach for assessing the stability and reproducibility of mass spectra obtained via ambient ionization methods. This method is suitable for both comparing experiments during which only one mass... more
In this work, we demonstrate a new approach for assessing the stability and reproducibility of mass spectra obtained via ambient ionization methods. This method is suitable for both comparing experiments during which only one mass spectrum is measured and for evaluating the internal homogeneity of mass spectra collected over a period of time. The approach uses Pearson’s r coefficient and the cosine measure to compare the spectra. It is based on the visualization of dissimilarities between measurements, thus leading to the analysis of dissimilarity patterns. The cosine measure and correlations are compared to obtain better metrics for spectra homogeneity. The method filters out unreliable scans to prevent the analyzed sample from being wrongly characterized. The applicability of the method is demonstrated on a set of brain tumor samples. The developed method could be employed in neurosurgical applications, where mass spectrometry is used to monitor the intraoperative tumor border.
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The development of perspective diagnostic techniques in medicine requires efficient high-throughput biological sample analysis methods. Here, we present an inline cartridge extraction that facilitates the screening rate of mass... more
The development of perspective diagnostic techniques in medicine requires efficient high-throughput biological sample analysis methods. Here, we present an inline cartridge extraction that facilitates the screening rate of mass spectrometry shotgun lipidomic analysis of tissue samples. We illustrate the method by its application to tumor tissue identification in neurosurgery. In perspective, this high-performance method provides new possibilities for the investigation of cancer pathogenesis and metabolic disorders.
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Alzheimer's disease (AD) is a multifactorial neurodegenerative disorder. Amyloid-β (Aβ) aggregation is likely to be the major cause of AD. In contrast to humans and other mammals, that share the same Aβ sequence, rats and mice are... more
Alzheimer's disease (AD) is a multifactorial neurodegenerative disorder. Amyloid-β (Aβ) aggregation is likely to be the major cause of AD. In contrast to humans and other mammals, that share the same Aβ sequence, rats and mice are invulnerable to AD-like neurodegenerative pathologies, and Aβ of these rodents (ratAβ) has three amino acid substitutions in the metal-binding domain 1-16 (MBD). Angiotensin-converting enzyme (ACE) cleaves Aβ-derived peptide substrates, however, there are contradictions concerning the localization of the cleavage sites within Aβ and the roles of each of the two ACE catalytically active domains in the hydrolysis. In the current study by using mass spectrometry and molecular modelling we have tested a set of peptides corresponding to MBDs of Aβ and ratAβ to get insights on the interactions between ACE and these Aβ species. It has been shown that the N-domain of ACE (N-ACE) acts as an arginine specific endopeptidase on the Aβ and ratAβ MBDs with C-amidate...
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Detection of the brain tumor margins is one of the most significant problems in neurosurgery. Several mass spectrometry-based approaches have been proposed recently for tumor boundary detection. One of them, spray from tissue does not... more
Detection of the brain tumor margins is one of the most significant problems in neurosurgery. Several mass spectrometry-based approaches have been proposed recently for tumor boundary detection. One of them, spray from tissue does not require sample preparation but needs special algorithms for analysis of its spectra. Here we proposed the feature selection algorithm designed for analysis of spray-from-tissue data.
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We report synthesis and application of the novel carboxylated styrene for internal calibration of Fourier transform ion cyclotron resonance mass-spectra of humic substances. The calibrant was synthesized in five steps from acetylsalicylic... more
We report synthesis and application of the novel carboxylated styrene for internal calibration of Fourier transform ion cyclotron resonance mass-spectra of humic substances. The calibrant was synthesized in five steps from acetylsalicylic acid (aspirin) followed by spontaneous polymerization of vinyl salicylic acid. Aromatic nature of the prepared polymer enabled its simultaneous analysis in the presence of the Suwannee River fulvic acid without using dual-spray approach. The major advantage of the calibrant proposed in this study is a lack of suppression of humic substances signals and maintenance of peak intensity distribution. The appropriate calibration resulted in an increased number of unambiguous identification in Suwannee River fulvic acid. Thanks to the higher mass accuracy, it was also possible to refine attribution of the CHOS species to hydrolysable tannins as opposed to the erroneous previous assignment to the condensed tannins.
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We report the investigation of the hydrothermal liquefaction products of the Spirulina platensis microalgae by using the Fourier transform ion cyclotron resonance mass spectrometry. The hydrothermal liquefaction produced two fractions:... more
We report the investigation of the hydrothermal liquefaction products of the Spirulina platensis microalgae by using the Fourier transform ion cyclotron resonance mass spectrometry. The hydrothermal liquefaction produced two fractions: one with boiling temperature below 300℃ and the dense residue that remained in the reactor. It was observed that N2 and N classes of compounds that dominate in the positive ESI Fourier transform ion cyclotron resonance spectra for both fractions, and that the light fraction is considerably more saturated then the heavy one. The performed hydrogen/deuterium exchange reaction indicated the presence of the onium compounds in the bio-oil.
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Here, we report a novel approach to enumeration of carboxylic groups carried by individual molecules of humic substances using selective chemical modification and isotopic labeling (deuteromethylation) and high-resolution electrospray... more
Here, we report a novel approach to enumeration of carboxylic groups carried by individual molecules of humic substances using selective chemical modification and isotopic labeling (deuteromethylation) and high-resolution electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry (ESI FTICR MS). Esterification was conducted with a use of thionyl chloride-deuteromethanol reagent under mild conditions to avoid transesterification. The deuteromethylated products were subjected to solid phase extraction using PPL Bond Elute cartridges prior to FTICR MS analysis. An amount of carboxyl groups in the individual molecular component was estimated from the length of identified deuteromethylation series. The method allowed for discerning between compounds with close elemental compositions possessing different protolytic properties. We found that different carboxylic moieties occupy distinct regions in molecular space of humic substances (HS) projected onto Van Krevelen...
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We present the application of the extended desolvating capillaries for the increasing the degree of the gas-phase H/D exchange reaction at atmospheric pressure. The use of the extended capillaries results in the increase of the time that... more
We present the application of the extended desolvating capillaries for the increasing the degree of the gas-phase H/D exchange reaction at atmospheric pressure. The use of the extended capillaries results in the increase of the time that ions spends in the high pressure region, what leads to the significant improvement of the efficiency of the reaction. For the small protein ubiquitin it was observed, that for the same temperature, number of exchanges increases with the decrease of the charge state so that the lowest charge state can exchange twice the number of hydrogen than the highest one. With the increase of the temperature, the difference decreases and eventually the number of exchanges equalizes for all charge states. The value of this temperature and the corresponding number of exchanges depends on the geometric parameters of the capillary. Further increase of the temperature leads to the thermal dissociation of the protein ion. The observed b/y fragments are identical to th...
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A novel atmospheric pressure thermal ionization (APTI) ion source was developed for the analysis of liquid samples. The feasibility of the ion source was demonstrated on peptides using two configurations—assisted by hot wire or hot... more
A novel atmospheric pressure thermal ionization (APTI) ion source was developed for the analysis of liquid samples. The feasibility of the ion source was demonstrated on peptides using two configurations—assisted by hot wire or hot surface. Microalloyed molybdenum, used as a thermal ion-emitter, notably facilitated the formation of multiply-charged ions, but fragmentation products were still observed. Peptide fragmentation accompanying thermal ionization can be used for peptide identification. The described method is promising for studies of biological samples with minimal pre-treatment.
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The importance of high-resolution mass spectrometry for the correct data interpretation of a direct tissue analysis is demonstrated with an example of its clinical application for an endometriosis study. Multivariate analysis of the data... more
The importance of high-resolution mass spectrometry for the correct data interpretation of a direct tissue analysis is demonstrated with an example of its clinical application for an endometriosis study. Multivariate analysis of the data discovers lipid species differentially expressed in different tissues under investigation. High-resolution mass spectrometry allows unambiguous separation of peaks with close masses that correspond to proton and sodium adducts of phosphatidylcholines and to phosphatidylcholines differing in double bond number.
Research Interests: Algorithms, Chemistry, Analytical Chemistry, Mass Spectrometry, Biomarkers, and 14 moreMedicine, Multivariate Analysis, Lipids, Humans, Computer Simulation, Female, Liquid Chromatography / Electrospray Ionization Mass Spectrometry, Sodium, Fourier transform ion cyclotron resonance, Reproducibility of Results, Statistical models, Ovarian cysts, Sensitivity and Specificity, and Protons
Recently Russian archeologists have discovered on Taman peninsula an ancient (V B.C.) Greek amphora full of dense bitumen. This is the oldest amphora in the world that contains bitumen. We report the investigation of this bitumen using... more
Recently Russian archeologists have discovered on Taman peninsula an ancient (V B.C.) Greek amphora full of dense bitumen. This is the oldest amphora in the world that contains bitumen. We report the investigation of this bitumen using ultrahigh resolution Fourier transform mass spectrometry. Also we used recently developed in-ESI source Hydrogen/Deuterium exchange approach for the structural characterization of the individual molecules and estimation of the biodegradation of the bitumen. The increase of number of the labile hydrogens compared to the non-degraded oil can serve as an additional evidence of the degradation of bitumen via oxidation. For the facilitation of the spectrum processing we have developed the special iterative spectrum reduction approach. It was observed that molecules that have only oxygen heteroatoms possess two -OH groups what is unusual for the petroleum. Based on this we suggested that the bitumen degraded during its being in amphora for 2500 years. Copyr...
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The electrospray laser desorption/ionization (ELDI) method is actively used for direct sample analysis and ambient mass spectrometry imaging. The optimizing of laser desorption conditions is essential for this technology. In this work, we... more
The electrospray laser desorption/ionization (ELDI) method is actively used for direct sample analysis and ambient mass spectrometry imaging. The optimizing of laser desorption conditions is essential for this technology. In this work, we propose using a metal target with a black oxide (Fe3O4) coating to increase the signal in ELDI-MS for peptides and small proteins. The experiments were performed on an LTQ-FT mass spectrometer equipped with a home-made ELDI ion source. A cutter blade with black oxide coating was used as a target. A nitrogen laser was used with the following parameters: 337 nm, pulse duration 4 ns, repetition rate 10 Hz, fluence ∼ 700 J m−2. More than a five times signal increase was observed for a substance P peptide when a coated and a non-coated metal target were compared. No ion signal was observed for proteins if the same fluence and the standard stainless steel target were used. With the assistance of the Fe3O4 coated metal target and a relatively low laser fl...
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Exhaled breath condensate (EBC) reflects the composition of the airway-lining fluid and may contain biomarkers of diseases of respiratory system. The aim of this study is to identify proteins in EBC of patients with chronic obstructive... more
Exhaled breath condensate (EBC) reflects the composition of the airway-lining fluid and may contain biomarkers of diseases of respiratory system. The aim of this study is to identify proteins in EBC of patients with chronic obstructive pulmonary disease (COPD) and pneumonia using two techniques of proteome identification. Seventeen COPD and thirteen pneumonia samples were collected using the Jaeger ECoScreen (VIASYS Healthcare, Germany), freeze dried, treated with trypsin and analyzed by nanoflow LC-MS/MS with a 7-Tesla Finnigan LTQ-FT mass spectrometer (Thermo Electron, Germany). Six COPD samples were mixed and applied to 2D-PAAGE by Mini-PROTEAN system (Bio-RAD, USA). Silver stained spots were analyzed by MALDI-TOF-MS using a Microflex device (Bruker Daltonics, Germany). Using 2D-PAAGE and MALDI-TOF-MS we were able to show that EBC samples from patients with COPD contain whole “normal” keratins that were detected also in EBC of healthy donors. Using LC-MS/MS, a method of comparable sensitivity, specific peptides of “abnormal” keratins 3, 4, 8 were identified in COPD samples. Keratin set identified in samples from patients with acute pneumonia was more varied. Peptides of Plakoglobin, Desmoplakin, Alpha-1-acid glycoprotein, Filaggrin, Dynein, Collagen, Hornerin were discovered in COPD and pneumonia EBC samples. They are uncharacteristic of healthy EBC samples. None of these proteins was identified as a whole in 2D-PAA gels. These peptides seem to appear in airway-lining fluid due to proteolysis in respiratory tract tissue. In conclusion, each of “abnormal” peptides, as well as their combinations, may have diagnostic value.
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ABSTRACT Without Abstract
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Isotopic exchange approach coupled to high-resolution mass spectrometry has become the power analytical approach for a wide range of analytical and bioanalyticall applications. Considerable efforts have been dedicated to developing fast... more
Isotopic exchange approach coupled to high-resolution mass spectrometry has become the power analytical approach for a wide range of analytical and bioanalyticall applications. Considerable efforts have been dedicated to developing fast exchange techniques directly in the ionization source. But all such methods are limited to the hydrogen/deuterium exchange approaches. In this paper we demonstrate that certain types of oxygen atoms can also be exchanged for (18)O on the time scale of the ionization process. Using HIO3 and NaIO4 and by infusing the heavy water H2(18)O in the ESI source we have demonstrated that it is possible to obtain a high level of oxygen exchange. It was observed that the rate of this exchange depends to a large extent on the temperature of the desolvating capillary of the mass spectrometer. Several other species, such as peptides, oligonucleotides and low weight organic molecules, were subjected to in-ESI (16)O/(18)O exchange but the exchange was not observed.
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Research Interests: Engineering, Chemistry, Mass Spectrometry, Medicine, Biological Sciences, and 11 moreLipids, Brain, Humans, CHEMICAL SCIENCES, Liquid Chromatography / Electrospray Ionization Mass Spectrometry, Ionization, Analytical and Bioanalytical Chemistry, Brain Chemistry, Equipment Design, Brain Neoplasms, and Electrospray Ionization
The formation of metal-peptide complexes during electrospray ionization (ESI) is a widely known phenomenon and is often considered to be undesirable. Such effect considerably limits the use of ESI mass spectrometry for the investigation... more
The formation of metal-peptide complexes during electrospray ionization (ESI) is a widely known phenomenon and is often considered to be undesirable. Such effect considerably limits the use of ESI mass spectrometry for the investigation of biologically relevant metal-peptide compounds that are present in the solution and play critical roles in many bioprocesses such as progression of neurodegenerative diseases. In the article, it is demonstrated that under specific conditions such as high temperature of the desolvating capillary, an interesting effect, which can be called as &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39;supermetallization&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39;, occurs. Using a model peptide Αβ amyloid domain 1-16, it was observed that an increase in the temperature of the desolvating capillary results in multiple substitutions of hydrogen atoms by Zn atoms in this peptide. At high temperatures (T ~ 400 °C), up to 11 zinc atoms can be covalently bound to (1-16) Αβ. It was observed that supermetallization of (1-16) Αβ depends on the solvent composition and pH. Supermetallization was also demonstrated for proteins, such as ubiquitin and cytochrome C. That proves that the supermetallization is a general phenomenon for peptides and proteins. For the structural investigation of supermetallized complexes, electron-capture dissociation (ECD) fragmentation was applied. The effect of hydrogen rearranging during ECD was observed. In addition, quantum chemical calculations were used to estimate the possible structures of different supermetallized complexes. These results allow a more deep understanding of the limitations of the use of ESI mass spectrometry for the investigation of biologically relevant metal-peptide complexes. Copyright © 2015 John Wiley &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp; Sons, Ltd.
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In the paper, we have demonstrated the possibility of performing hydrogen/deuterium (H/D) exchange of proteins in the region of gas-phase ion formation in an electrospray ion source by saturating the electrospray ionization source with... more
In the paper, we have demonstrated the possibility of performing hydrogen/deuterium (H/D) exchange of proteins in the region of gas-phase ion formation in an electrospray ion source by saturating the electrospray ionization source with vapors of a deuterating agent (D(2)O or MeOD). In this region, charged droplets are shrinking and the protein ions transfer into the gas phase. As a model protein, we have used ubiquitin whose ion mobility spectrometry and gas-phase H/D exchange in the vacuum part of a mass spectrometer demonstrated the presence of gas-phase conformers with different cross sections and H/D exchange rates. In our experiments, we observed monomodal deuterium distributions for all solvents, charge states, desolvating capillary temperature and types of deuterating agent. Also, we found that the number of H/D exchanges increases with an increasing desolvating capillary temperature and decreasing charge state. We observed that solution composition (49 : 50 : 1 H(2)O : MeOH ...