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Age-Dependent Increase In Ortho-Tyrosine And Methionine Sulfoxide In Human Skin Collagen Is Not Accelerated In Diabetes: Evidence Against A Generalized Increase In Oxidative Stress In Diabetes, Mary C. Wells-Knecht, Timothy J. Lyons, David R. Mccance, Suzanne R. Thorpe, John W. Baynes
Age-Dependent Increase In Ortho-Tyrosine And Methionine Sulfoxide In Human Skin Collagen Is Not Accelerated In Diabetes: Evidence Against A Generalized Increase In Oxidative Stress In Diabetes, Mary C. Wells-Knecht, Timothy J. Lyons, David R. Mccance, Suzanne R. Thorpe, John W. Baynes
Faculty Publications
The glycoxidation products Nepsilon-(carboxymethyl)lysine and pentosidine increase in skin collagen with age and at an accelerated rate in diabetes. Their age-adjusted concentrations in skin collagen are correlated with the severity of diabetic complications. To determine the relative roles of increased glycation and/or oxidation in the accelerated formation of glycoxidation products in diabetes, we measured levels of amino acid oxidation products, distinct from glycoxidative modifications of amino acids, as independent indicators of oxidative stress and damage to collagen in aging and diabetes. We show that ortho-tyrosine and methionine sulfoxide are formed in concert with Nepsilon-(carboxymethyl)lysine and pentosidine during glycoxidation of collagen …
Carboxymethylethanolamine, A Biomarker Of Phospholipid Modification During The Maillard Reaction In Vivo, Jesus R. Requena, Mahtab U. Ahmed, C. Wesley Fountain, Thorsten P. Degenhardt, Sharanya Reddy, Cliff Perez, Timothy J. Lyons, Alicia J. Jenkins, John W. Baynes, Suzanne R. Thorpe
Carboxymethylethanolamine, A Biomarker Of Phospholipid Modification During The Maillard Reaction In Vivo, Jesus R. Requena, Mahtab U. Ahmed, C. Wesley Fountain, Thorsten P. Degenhardt, Sharanya Reddy, Cliff Perez, Timothy J. Lyons, Alicia J. Jenkins, John W. Baynes, Suzanne R. Thorpe
Faculty Publications
Nepsilon-(Carboxymethyl)lysine (CML) is a stable chemical modification of proteins formed from both carbohydrates and lipids during autoxidation reactions. We hypothesized that carboxymethyl lipids such as (carboxymethyl)phosphatidylethanolamine (carboxymethyl-PE) would also be formed in these reactions, and we therefore developed a gas chromatography-mass spectrometry assay for quantification of carboxymethylethanolamine (CME) following hydrolysis of phospholipids. In vitro, CME was formed during glycation of dioleoyl-PE under air and from linoleoylpalmitoyl-PE, but not from dioleoyl-PE, in the absence of glucose. In vivo, CME was detected in lipid extracts of red blood cell membranes, approximately 0.14 mmol of CME/mol of ethanolamine, from control and diabetic subjects, …
Semiclassical Approach To The Hydrogen-Exchange Reaction- Reactive And Transition-State Dynamics, Sophya V. Garashchuk, Grossmann Frank, David Tannor
Semiclassical Approach To The Hydrogen-Exchange Reaction- Reactive And Transition-State Dynamics, Sophya V. Garashchuk, Grossmann Frank, David Tannor
Faculty Publications
Scattering matrix elements and symmetric transition-state resonances for the collinear H 2 + H → H + H 2 reaction are obtained using a time-dependent approach. The correlation function between reactant channel wavepackets and product channel wavepackets is used to determine the S-matrix elements. In a similar fashion, autocorrelation functions are used to extract the positions and widths of transition-state resonances. The time propagation of the wavepackets is performed by the improved semiclassical frozen Gaussian method of Herman and Kluk, which is an initial value, uniformly converged method. The agreement between the quantum and semiclassical results is far better …