rticaine hydrochloride, 4-methyl-3(2-[propylaino]propionamido)-2-thiophenecarboxylic acid, ethyl ... more rticaine hydrochloride, 4-methyl-3(2-[propylaino]propionamido)-2-thiophenecarboxylic acid, ethyl ester hydrochloride, is a local anaesthetic ommonly used in dentistry, and is classified as an mide local anaesthetic. Solid-state 13C and 31P NMR ere used to investigate the uncharged articaine species sample pH of 10.0) when interacting with distearoyl hosphatidylcholine (DSPC) model membranes. The SPC phospholipid bilayer was studied at four different olar ratios of articaine, 10, 25, 40, and 55 mol%, espectively. The articaine concentration dependent ecrease in the DSPC bilayer gel to liquid crystalline hase-transition temperature demonstrates substantial rticaine interaction with this bilayer. A DSPC bilayer ontains a large hydrophobic core and the 13C and 1P NMR spectra of the 40 mol% articaine containing ample demonstrate a disturbance in the molecular acking of the polar bilayer region that extends into the ydrophobic region, evidenced by carbon 2 and 3 of he stearoyl acyl chains...
The interaction of coenzyme Q10 (CoQ10) in a monolayer of 1,2-dipalmitoyl-sn-glysero-3-phospho-L-... more The interaction of coenzyme Q10 (CoQ10) in a monolayer of 1,2-dipalmitoyl-sn-glysero-3-phospho-L-choline (DPPC), in a monolayer of 1,2-dierucoyl-sn-glysero-3-phospho-L-choline (DEPC), in a monolayer of 1-palmitoyl-2-oleoyl-sn-glysero-3-phospho-L-serine (POPS) and in a monolayer of total lipid extract from pig brain (PB) has been investigated by using the Langmuir monolayer technique. Surface pressure (π)-mean molecular area (mma) isotherms have been measured for pure lipid monolayers and lipid monolayers with 0.5, 1.0, 2.0, 5.0 and 10.0 mol% CoQ10 concentrations. At the biological concentration (1.0-3.0 mol%) of CoQ10, intercalation of CoQ10 occurs in the lipid acyl chains of DPPC, POPS and PB monolayers. Above the biological concentration of CoQ10, the CoQ10 molecule induces domain formation in the monolayers of DPPC, POPS and PB lipids. The DEPC monolayer behavior deviates from the other lipids in this study. At 2.0 mol% the CoQ10 promotes very dense lipid packing, and the CoQ10 molecule is located parallel to the DEPC acyl chains at all concentrations.
Journal of Biomolecular Structure and Dynamics, 1998
Experimentally observed sequence-selective binding of metal ion to DNA oligonucleotides have been... more Experimentally observed sequence-selective binding of metal ion to DNA oligonucleotides have been compared with variations of electrostatic potential (EP) along the helix. Calculations of EP have been performed for three atomic models of the oligonucleotide duplex [d(CGCGAATTCGCG)2] using several variants of EP calculations, including a solution of non-linear Poisson-Boltzmann equation (NPBE). N7 atom of guanine adjacent to adenine base was identified as a region with the most negative electrostatic potential in the major groove. The EP value for the Me ion binding site surpasses the value for N7 of other guanines by 10-26% depending on particular duplex conformation. Qualitatively, the sequence dependent variations of EP near guanine N7 atoms are in agreement with the sequence-selective behavior of Mn(II) and Zn(II) ions as revealed by NMR experiments. But the difference in EP between the two most negative regions near guanine N7 atoms does not exceed 1.25 kT/e. Simple model suggests that metal ions are capable to form ion-hydrate complexes with G-Pu steps of DNA duplex. These complexes are formed via one Me...G and five Me...water coordination bonds with water molecules hydrogen bonded to two adjacent purine bases in the same chain. We suppose that such a stereospecific structural possibility is the main factor which control the sequence-selectivity in the metal ion binding. A combination of both mechanisms allows to explain sequence specific Mn(II) and Zn(II) binding to a set of oligonucleotides.
We have applied diffusion and relaxation Nuclear Magnetic Resonance experiments to investigate th... more We have applied diffusion and relaxation Nuclear Magnetic Resonance experiments to investigate the translational and rotational mobility of adsorbents on quartz and calcite mineral surfaces. On both surfaces it was found that water is the dominant molecule. On the quartz surface the majority of water molecules have a relatively high degree of both rotational and translational mobility, while a minor fraction of water molecules, and all hydrocarbon molecules, have a significantly lower mobility. On the calcite surface the translational mobility is very low for all the adsorbed molecules, while there is a large diversity in rotational mobility, indicating that the hydrocarbon molecules are strongly attached to the surface, but that some part of each molecule still have a large degree of rotational mobility. Diffusion and relaxation experiments give a detailed description of both the molecular mobility of adsorbed species on these mineral surfaces, which leads to new insight with respect to aging processes on a molecular level.
After nearly a century of research on water properties at interfaces it has become clear that wat... more After nearly a century of research on water properties at interfaces it has become clear that water adopts a highly ordered structure near a solid surface. However, to date, the exact orientations and structures of water molecules adjacent to a solid surface remain within the realm of theoretical simulation. In this paper, the average orientation of water molecules near a silica surface is determined experimentally for the first time using a sample where silica surfaces are similarly oriented with respect to an external magnetic field. By allowing only water with increased ordering to remain in the closed system, the water 1H magnetic resonance corresponds to an orientation-dependent doublet. From its orientation dependence, the average angle between the silica surface and the water 1H–1H vector is assessed to 78° at ambient conditions. This orientation is found to apply to tetrahedrally coordinated water molecules not directly adjacent the surface and suggests that water in subsequent layers adopt a low-...
MRI and solid-state NMR can determine both macroscopic and molecular-level features of salmon by ... more MRI and solid-state NMR can determine both macroscopic and molecular-level features of salmon by measuring directly on tissues.
Journal of Biomolecular Structure and Dynamics, 1998
Experimentally observed sequence-selective binding of metal ion to DNA oligonucleotides have been... more Experimentally observed sequence-selective binding of metal ion to DNA oligonucleotides have been compared with variations of electrostatic potential (EP) along the helix. Calculations of EP have been performed for three atomic models of the oligonucleotide duplex [d(CGCGAATTCGCG)2] using several variants of EP calculations, including a solution of non-linear Poisson-Boltzmann equation (NPBE). N7 atom of guanine adjacent to adenine base was identified as a region with the most negative electrostatic potential in the major groove. The EP value for the Me ion binding site surpasses the value for N7 of other guanines by 10-26% depending on particular duplex conformation. Qualitatively, the sequence dependent variations of EP near guanine N7 atoms are in agreement with the sequence-selective behavior of Mn(II) and Zn(II) ions as revealed by NMR experiments. But the difference in EP between the two most negative regions near guanine N7 atoms does not exceed 1.25 kT/e. Simple model suggests that metal ions are capable to form ion-hydrate complexes with G-Pu steps of DNA duplex. These complexes are formed via one Me...G and five Me...water coordination bonds with water molecules hydrogen bonded to two adjacent purine bases in the same chain. We suppose that such a stereospecific structural possibility is the main factor which control the sequence-selectivity in the metal ion binding. A combination of both mechanisms allows to explain sequence specific Mn(II) and Zn(II) binding to a set of oligonucleotides.
To evaluate whether the sugar moieties of short DNA duplexes exhibit local motion of sufficient a... more To evaluate whether the sugar moieties of short DNA duplexes exhibit local motion of sufficient amplitude to affect interproton distance measurements, we have carried out a series of time-dependent NOESY experiments at increasingly shorter mixing times on dodecamer DNA duplexes. By use of the cytosine H5-H6 vector as a known distance in the bases and the geminal 2'H-2''H vector as a known distance in the sugars, the corresponding apparent cross-relaxation rates were sampled at various mixing times. While the ratio of the inverse sixth power of these two fixed distances is in the range 6-7, when the system is sampled at 100 ms the apparent initial rate of growth of the 2'H-2''H NOESY crosspeak is only 1.9-2.0 times faster than that of the H5-H6 crosspeak--in agreement with the results of Clore and Gronenborn [Clore, G. M., & Gronenborn, A. M. (1984) FEBS Lett. 172, 219; (1984) FEBS Lett. 175, 117] and of Gronenborn and Clore [Gronenborn, A. M., & Clore, G. M. (1985) Prog. NMR Spectrosc. 17, 1]. This observation was interpreted to indicate the existence of internal mobility with a 3-fold shorter correlation time for the sugar moieties in DNA and led to the use of this shorter correlation time to estimate sugar-sugar proton distances and many sugar-base proton distances in subsequent DNA structure determination. We have examined 2'H-2"H cross-relaxation and H5-H6 cross-relaxation at 100, 90, 60, 30, and 15 ms in dodecamer DNA duplexes.(ABSTRACT TRUNCATED AT 250 WORDS)
rticaine hydrochloride, 4-methyl-3(2-[propylaino]propionamido)-2-thiophenecarboxylic acid, ethyl ... more rticaine hydrochloride, 4-methyl-3(2-[propylaino]propionamido)-2-thiophenecarboxylic acid, ethyl ester hydrochloride, is a local anaesthetic ommonly used in dentistry, and is classified as an mide local anaesthetic. Solid-state 13C and 31P NMR ere used to investigate the uncharged articaine species sample pH of 10.0) when interacting with distearoyl hosphatidylcholine (DSPC) model membranes. The SPC phospholipid bilayer was studied at four different olar ratios of articaine, 10, 25, 40, and 55 mol%, espectively. The articaine concentration dependent ecrease in the DSPC bilayer gel to liquid crystalline hase-transition temperature demonstrates substantial rticaine interaction with this bilayer. A DSPC bilayer ontains a large hydrophobic core and the 13C and 1P NMR spectra of the 40 mol% articaine containing ample demonstrate a disturbance in the molecular acking of the polar bilayer region that extends into the ydrophobic region, evidenced by carbon 2 and 3 of he stearoyl acyl chains...
The interaction of coenzyme Q10 (CoQ10) in a monolayer of 1,2-dipalmitoyl-sn-glysero-3-phospho-L-... more The interaction of coenzyme Q10 (CoQ10) in a monolayer of 1,2-dipalmitoyl-sn-glysero-3-phospho-L-choline (DPPC), in a monolayer of 1,2-dierucoyl-sn-glysero-3-phospho-L-choline (DEPC), in a monolayer of 1-palmitoyl-2-oleoyl-sn-glysero-3-phospho-L-serine (POPS) and in a monolayer of total lipid extract from pig brain (PB) has been investigated by using the Langmuir monolayer technique. Surface pressure (π)-mean molecular area (mma) isotherms have been measured for pure lipid monolayers and lipid monolayers with 0.5, 1.0, 2.0, 5.0 and 10.0 mol% CoQ10 concentrations. At the biological concentration (1.0-3.0 mol%) of CoQ10, intercalation of CoQ10 occurs in the lipid acyl chains of DPPC, POPS and PB monolayers. Above the biological concentration of CoQ10, the CoQ10 molecule induces domain formation in the monolayers of DPPC, POPS and PB lipids. The DEPC monolayer behavior deviates from the other lipids in this study. At 2.0 mol% the CoQ10 promotes very dense lipid packing, and the CoQ10 molecule is located parallel to the DEPC acyl chains at all concentrations.
Journal of Biomolecular Structure and Dynamics, 1998
Experimentally observed sequence-selective binding of metal ion to DNA oligonucleotides have been... more Experimentally observed sequence-selective binding of metal ion to DNA oligonucleotides have been compared with variations of electrostatic potential (EP) along the helix. Calculations of EP have been performed for three atomic models of the oligonucleotide duplex [d(CGCGAATTCGCG)2] using several variants of EP calculations, including a solution of non-linear Poisson-Boltzmann equation (NPBE). N7 atom of guanine adjacent to adenine base was identified as a region with the most negative electrostatic potential in the major groove. The EP value for the Me ion binding site surpasses the value for N7 of other guanines by 10-26% depending on particular duplex conformation. Qualitatively, the sequence dependent variations of EP near guanine N7 atoms are in agreement with the sequence-selective behavior of Mn(II) and Zn(II) ions as revealed by NMR experiments. But the difference in EP between the two most negative regions near guanine N7 atoms does not exceed 1.25 kT/e. Simple model suggests that metal ions are capable to form ion-hydrate complexes with G-Pu steps of DNA duplex. These complexes are formed via one Me...G and five Me...water coordination bonds with water molecules hydrogen bonded to two adjacent purine bases in the same chain. We suppose that such a stereospecific structural possibility is the main factor which control the sequence-selectivity in the metal ion binding. A combination of both mechanisms allows to explain sequence specific Mn(II) and Zn(II) binding to a set of oligonucleotides.
We have applied diffusion and relaxation Nuclear Magnetic Resonance experiments to investigate th... more We have applied diffusion and relaxation Nuclear Magnetic Resonance experiments to investigate the translational and rotational mobility of adsorbents on quartz and calcite mineral surfaces. On both surfaces it was found that water is the dominant molecule. On the quartz surface the majority of water molecules have a relatively high degree of both rotational and translational mobility, while a minor fraction of water molecules, and all hydrocarbon molecules, have a significantly lower mobility. On the calcite surface the translational mobility is very low for all the adsorbed molecules, while there is a large diversity in rotational mobility, indicating that the hydrocarbon molecules are strongly attached to the surface, but that some part of each molecule still have a large degree of rotational mobility. Diffusion and relaxation experiments give a detailed description of both the molecular mobility of adsorbed species on these mineral surfaces, which leads to new insight with respect to aging processes on a molecular level.
After nearly a century of research on water properties at interfaces it has become clear that wat... more After nearly a century of research on water properties at interfaces it has become clear that water adopts a highly ordered structure near a solid surface. However, to date, the exact orientations and structures of water molecules adjacent to a solid surface remain within the realm of theoretical simulation. In this paper, the average orientation of water molecules near a silica surface is determined experimentally for the first time using a sample where silica surfaces are similarly oriented with respect to an external magnetic field. By allowing only water with increased ordering to remain in the closed system, the water 1H magnetic resonance corresponds to an orientation-dependent doublet. From its orientation dependence, the average angle between the silica surface and the water 1H–1H vector is assessed to 78° at ambient conditions. This orientation is found to apply to tetrahedrally coordinated water molecules not directly adjacent the surface and suggests that water in subsequent layers adopt a low-...
MRI and solid-state NMR can determine both macroscopic and molecular-level features of salmon by ... more MRI and solid-state NMR can determine both macroscopic and molecular-level features of salmon by measuring directly on tissues.
Journal of Biomolecular Structure and Dynamics, 1998
Experimentally observed sequence-selective binding of metal ion to DNA oligonucleotides have been... more Experimentally observed sequence-selective binding of metal ion to DNA oligonucleotides have been compared with variations of electrostatic potential (EP) along the helix. Calculations of EP have been performed for three atomic models of the oligonucleotide duplex [d(CGCGAATTCGCG)2] using several variants of EP calculations, including a solution of non-linear Poisson-Boltzmann equation (NPBE). N7 atom of guanine adjacent to adenine base was identified as a region with the most negative electrostatic potential in the major groove. The EP value for the Me ion binding site surpasses the value for N7 of other guanines by 10-26% depending on particular duplex conformation. Qualitatively, the sequence dependent variations of EP near guanine N7 atoms are in agreement with the sequence-selective behavior of Mn(II) and Zn(II) ions as revealed by NMR experiments. But the difference in EP between the two most negative regions near guanine N7 atoms does not exceed 1.25 kT/e. Simple model suggests that metal ions are capable to form ion-hydrate complexes with G-Pu steps of DNA duplex. These complexes are formed via one Me...G and five Me...water coordination bonds with water molecules hydrogen bonded to two adjacent purine bases in the same chain. We suppose that such a stereospecific structural possibility is the main factor which control the sequence-selectivity in the metal ion binding. A combination of both mechanisms allows to explain sequence specific Mn(II) and Zn(II) binding to a set of oligonucleotides.
To evaluate whether the sugar moieties of short DNA duplexes exhibit local motion of sufficient a... more To evaluate whether the sugar moieties of short DNA duplexes exhibit local motion of sufficient amplitude to affect interproton distance measurements, we have carried out a series of time-dependent NOESY experiments at increasingly shorter mixing times on dodecamer DNA duplexes. By use of the cytosine H5-H6 vector as a known distance in the bases and the geminal 2'H-2''H vector as a known distance in the sugars, the corresponding apparent cross-relaxation rates were sampled at various mixing times. While the ratio of the inverse sixth power of these two fixed distances is in the range 6-7, when the system is sampled at 100 ms the apparent initial rate of growth of the 2'H-2''H NOESY crosspeak is only 1.9-2.0 times faster than that of the H5-H6 crosspeak--in agreement with the results of Clore and Gronenborn [Clore, G. M., & Gronenborn, A. M. (1984) FEBS Lett. 172, 219; (1984) FEBS Lett. 175, 117] and of Gronenborn and Clore [Gronenborn, A. M., & Clore, G. M. (1985) Prog. NMR Spectrosc. 17, 1]. This observation was interpreted to indicate the existence of internal mobility with a 3-fold shorter correlation time for the sugar moieties in DNA and led to the use of this shorter correlation time to estimate sugar-sugar proton distances and many sugar-base proton distances in subsequent DNA structure determination. We have examined 2'H-2"H cross-relaxation and H5-H6 cross-relaxation at 100, 90, 60, 30, and 15 ms in dodecamer DNA duplexes.(ABSTRACT TRUNCATED AT 250 WORDS)
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