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Full-Text Articles in Physical Sciences and Mathematics
Electronegativity And Bond Type 2. Evaluation Of Electronegativity Scales, Gordon Sproul
Electronegativity And Bond Type 2. Evaluation Of Electronegativity Scales, Gordon Sproul
Faculty Publications
No abstract provided.
Oxidized Amino Acids In Lens Protein With Age: Measurement Of O-Tyrosine And Dityrosine In The Aging Human Lens, Mary C. Wells-Knect, Thomas G. Huggins, Daniel G. Dyer, Suzanne R. Thorpe, John W. Baynes
Oxidized Amino Acids In Lens Protein With Age: Measurement Of O-Tyrosine And Dityrosine In The Aging Human Lens, Mary C. Wells-Knect, Thomas G. Huggins, Daniel G. Dyer, Suzanne R. Thorpe, John W. Baynes
Faculty Publications
The concentrations of ortho-tyrosine (o-Tyr) and dityrosine (DT) were measured in noncataractous human lenses in order to assess the role of proteinoxidation reactions in the aging of lens proteins. The measurements were conducted by selected ion monitoring-gas chromatography/mass spectrometry using deuterium-labeled internal standards, which provided both high sensitivity and specificity for the quantitation of o-Tyr and DT. Between ages 1 and 78 years, the o-Tyr concentration in lens proteins varied from 0.3 to 0.9 mmol of o-Tyr/mol of Phe (n = 19), while DT ranged from 1 to 3 mumol of DT/mol of Tyr (n = 30). There were no …
Formation Of O-Tyrosine And Dityrosine In Proteins During Radiolytic And Metal-Catalyzed Oxidation, Thomas G. Huggins, Mary C. Wells-Knecht, Nicholas A. Detorie, John W. Baynes, Suzanna R. Thorpe
Formation Of O-Tyrosine And Dityrosine In Proteins During Radiolytic And Metal-Catalyzed Oxidation, Thomas G. Huggins, Mary C. Wells-Knecht, Nicholas A. Detorie, John W. Baynes, Suzanna R. Thorpe
Faculty Publications
To evaluate their usefulness as chemical indicators of cumulative oxidative damage to proteins, we studied the kinetics and extent of formation of ortho-tyrosine (0-Tyr), dityrosine (DT), and dityrosine-like fluorescence (Ex = 3 17 nm, E,,, = 407 nm) in the model proteins RNase and lysozyme exposed to radiolytic and metalcatalyzed (H20z/Cu2+) oxidation (MCO). Although there were protein-dependent differences, o-Tyr, DT, and fluorescence increased coordinately during oxidation of the proteins in both oxidation systems. The contribution of DT to total dityrosine-like fluorescence in oxidized proteins varied from 2-10070, depending on the protein, type of oxidation, and extent of oxidative damage. In …
Accumulation Of Maillard Reaction Products In Skin Collagen In Diabetes And Aging, Daniel G. Dyer, John A. Dunn, Suzanne R. Thorpe, Karen E. Bailie, Timothy L. Lyons, David R. Mccance, John W. Baynes
Accumulation Of Maillard Reaction Products In Skin Collagen In Diabetes And Aging, Daniel G. Dyer, John A. Dunn, Suzanne R. Thorpe, Karen E. Bailie, Timothy L. Lyons, David R. Mccance, John W. Baynes
Faculty Publications
To investigate the contribution of glycation and oxidation reactions to the modification of insoluble collagen in aging and diabetes, Maillard reaction products were measured in skin collagen from 39 type 1 diabetic patients and 52 nondiabetic control subjects. Compounds studied included fructoselysine (FL), the initial glycation product, and the glycoxidation products, N epsilon-(carboxymethyl) lysine (CML) and pentosidine, formed during later Maillard reactions. Collagen-linked fluorescence was also studied. In nondiabetic subjects, glycation of collagen (FL content) increased only 33% between 20 and 85 yr of age. In contrast, CML, pentosidine and fluorescence increased five-fold, correlating strongly with age. In diabetic patients, …
Maillard Reaction Products And Their Relation To Complications In Insulin-Dependent Diabetes Mellitus, David R. Mccance, Daniel G. Dryer, John A. Dunn, Karen E. Bailie, Suzanne R. Thorpe, John W. Baynes, Timothy J. Lyons
Maillard Reaction Products And Their Relation To Complications In Insulin-Dependent Diabetes Mellitus, David R. Mccance, Daniel G. Dryer, John A. Dunn, Karen E. Bailie, Suzanne R. Thorpe, John W. Baynes, Timothy J. Lyons
Faculty Publications
Glycation, oxidation, and browning of proteins have all been implicated in the development of diabetic complications. We measured the initial Amadori adduct, fructoselysine (FL); two Maillard products, N epsilon-(carboxymethyl) lysine (CML) and pentosidine; and fluorescence (excitation = 328 nm, emission = 378 nm) in skin collagen from 39 type 1 diabetic patients (aged 41.5 +/- 15.3 [17-73] yr; duration of diabetes 17.9 +/- 11.5 [0-46] yr, [mean +/- SD, range]). The measurements were related to the presence of background (n = 9) or proliferative (n = 16) retinopathy; early nephropathy (24-h albumin excretion rate [AER24] > or = 20 micrograms/min; n …