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Chemistry

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Faculty Publications

1993

Articles 1 - 10 of 10

Full-Text Articles in Physical Sciences and Mathematics

Purification And Characterization Of A Gamma-Like Dna-Polymerase From Chenopodium Album L., K. Meißner, Sabine Heinhorst, Gordon C. Cannon, T. Börner Oct 1993

Purification And Characterization Of A Gamma-Like Dna-Polymerase From Chenopodium Album L., K. Meißner, Sabine Heinhorst, Gordon C. Cannon, T. Börner

Faculty Publications

A DNA polymerase activity from mitochondria of the dicotyledonous angiosperm Chenopodium album L. was purified almost 9000 fold by successive column chromatography steps on DEAE cellulose, heparin agarose and ssDNA cellulose. The enzyme was characterized as a gamma-class polymerase, based on its resistance to inhibitors of the nuclear DNA polymerase alpha and its preference for poly(rA).(dT)12-18 over activated DNA in vitro. The molecular weight was estimated to be 80,000 - 90,000. A 3' to 5' exonuclease activity was found to be tightly associated with the DNA polymerase activity through all purification steps. This is the first report of an association …

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Radially Symmetrical Flow Of Reacting Liquid With Changing Viscosity, S.E. Solovyov, V.A. Volpert, S.P. Davytan Aug 1993

Radially Symmetrical Flow Of Reacting Liquid With Changing Viscosity, S.E. Solovyov, V.A. Volpert, S.P. Davytan

Faculty Publications

Frontal regimens for one-dimensional flow of reacting liquid with changing viscosity are studied. Stationary solutions are investigated for the case of narrow reaction zones that shrink to a front. The results of numerical solution of the nonstationary problem are presented. Complex oscillations resulting from period-doubling bifurcations are found.

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Electronegativity And Bond Type 2. Evaluation Of Electronegativity Scales, Gordon Sproul Jul 1993

Electronegativity And Bond Type 2. Evaluation Of Electronegativity Scales, Gordon Sproul

Faculty Publications

No abstract provided.

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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 Jun 1993

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 …

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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 Jun 1993

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 …

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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 Jun 1993

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 …

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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 Jun 1993

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, …

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Development Of New Methods For Assessing Solidification/Stabilization Of Hazardous Waste Using Solid-State Nuclear Magnetic Resonance Techniques (Ph.D Dissertation, Lsu), Michael A. Janusa May 1993

Development Of New Methods For Assessing Solidification/Stabilization Of Hazardous Waste Using Solid-State Nuclear Magnetic Resonance Techniques (Ph.D Dissertation, Lsu), Michael A. Janusa

Faculty Publications

New methods for assessing solidification/stabilization (S/S) of hazardous waste using solid-state nuclear magnetic resonance are developed for the purpose of diagnosing on a microscopic level the performance of S/S as a hazardous waste disposal technique. There are four techniques developed and described in this dissertation: (1) Solid-state deuterium NMR spectroscopy is used to determine if a particular deuterated organic waste is effectively solidified/stabilized and to determine the lower limit of the bond strength between the waste and the cement matrix; (2) Constant time pulsed field gradient ^ NMR spectroscopy is tested on a liquid waste encapsulated within a solidified matrix …

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Solid-State Deuterium Nmr Spectroscopy Of D5-Phenol In White Portland Cement: A New Method For Assessing Solidification/Stabilization, Michael A. Janusa Jan 1993

Solid-State Deuterium Nmr Spectroscopy Of D5-Phenol In White Portland Cement: A New Method For Assessing Solidification/Stabilization, Michael A. Janusa

Faculty Publications

We have developed a new NMR-based procedure for studying waste/cement interactions. This is the first use of deuterium NMR spectroscopy to study waste solidification/ stabilization (S/S). The main feature of deuterium NMR spectroscopy is the ability to monitor molecular reorientations over a wide range of reorientation rates. This technique allows one to determine if a particular deuterated organic waste is effectively solidified/ stabilized and to determine the lower limit of the bond strength between the waste and the cement matrix. Comparison of the predicted and experimental deuterium NMR spectra show that phenol is mainly dissolved in pore waters and, thus, …

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Dna Replication In Chloroplasts, Sabine Heinhorst, Gordon C. Cannon Jan 1993

Dna Replication In Chloroplasts, Sabine Heinhorst, Gordon C. Cannon

Faculty Publications

Chloroplasts contain multiple copies of a DNA molecule (the plastome) that encodes many of the gene products required to perform photosynthesis. The plastome is replicated by nuclear-encoded proteins and its copy number seems to be highly regulated by the cell in a tissue-specific and developmental manner. Our understanding of the biochemical mechanism by which the plastome is replicated and the molecular basis for its regulation is limited. In this commentary we review our present understanding of chloroplast DNA replication and examine current efforts to elucidate its mechanism at a molecular level.

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