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Full-Text Articles in Physical Sciences and Mathematics
13C Nmr Investigation Of Nonenzymatic Glucosylation Of Protein, Carolyn I. Neglia, Helga J. Cohen, Albert R. Garber, Paul D. Ellis, Suzanne R. Thorpe, John W. Baynes
13C Nmr Investigation Of Nonenzymatic Glucosylation Of Protein, Carolyn I. Neglia, Helga J. Cohen, Albert R. Garber, Paul D. Ellis, Suzanne R. Thorpe, John W. Baynes
Faculty Publications
Nonenzymatic glucosylation of protein is initiated by the reversible condensation of glucose in its open chain form with the amino groups on the protein. The initial product is an aldimine (Schiff base) which cyclizes to the glycosylamine derivative. The aldimine can undergo a slow Amadori rearrangement to yield the relatively stable ketoamine adduct which is structurally analogous to fructose. 13C NMR has been used to characterize these early products of nonenzymatic glucosylation, using RNase A as a model protein. C-1 of the beta-pyranose anomer of the glycosylamine was identified at 88.8 ppm in the spectrum of RNase glucosylated approximately 1:1 …
Nonenzymatic Glucosylation And Glucose-Dependent Cross-Linking Of Protein, Albert S. Eble, Suzanne R. Thorpe, John W. Baynes
Nonenzymatic Glucosylation And Glucose-Dependent Cross-Linking Of Protein, Albert S. Eble, Suzanne R. Thorpe, John W. Baynes
Faculty Publications
A model system using RNase A has been established for studying the nonenzymatic glucosylation and glucose-dependent cross-linking of protein (Maillard reaction) under physiological conditions in vitro. The rate of glucosylation of RNase was first order in glucose. Glucosylation was accompanied by a comparable decrease in primary amino groups in the protein and lysine recoverable by amino acid analysis. Analysis of glucosylation reaction mixtures by sodium dodecyl sulfate-polyacrylamide gel electrophoresis in the presence of mercaptoethanol revealed the time-dependent formation of RNase dimer and trimer. The polymerization reaction was mixed order with respect to glucose concentration, but was approximately first order with …
The Metal In The Polarisable Interface Coupling With The Solvent Phase, Jerry Goodisman, Jean Paul Badiali, Martin Luc Rosinberg
The Metal In The Polarisable Interface Coupling With The Solvent Phase, Jerry Goodisman, Jean Paul Badiali, Martin Luc Rosinberg
Chemistry - All Scholarship
A quantum mechanical treatment of the conduction electrons of a metal in a polarisable interface shows that they can make an appreciable contribution to the electrical capacitance. Results for six metals are given, showing how differences in metal properties account qualitatively for experimentally observed differences in interfacial capacities, when the solvent is replaced by a dielectric film. To justify the neglect of solvent structure when metal properties are treated, the coupling between metal and solvent is discussed for orientable point solvent dipoles, and for a representation of the solvent polarisation by a pair of charged planes. The electron profile affects …
Density Functional Calculations For Liquid Metal Surfaces, Jerry Goodisman, M-L Rosinberg
Density Functional Calculations For Liquid Metal Surfaces, Jerry Goodisman, M-L Rosinberg
Chemistry - All Scholarship
Various forms for the ion density profiles of Cs and Na have been tested in the density functional formalism. The large oscillations expected for Coulombic systems are largely suppressed by the pseudopotential. While oscillatory profiles give some improvement in surface tension, the values obtained are still about twice the experimental ones. It is concluded that the treatment of the pseudopotential or the gradient expansion of the functional is responsible for the unsatisfactory results obtained.
On Surface Properties Of The One-Component Plasma, M-L Rosinberg, J-P Badiali, Jerry Goodisman
On Surface Properties Of The One-Component Plasma, M-L Rosinberg, J-P Badiali, Jerry Goodisman
Chemistry - All Scholarship
We consider a plasma of point ions in the presence of a non-uniform neutralising background. This background. the source of an external field, may have some of its parameters (density, form of surface profile, etc) modified, as long as the total charge is maintained. By considering such modifications in the context of the density-functional formalism for the ions, we prove sum rules giving the first and second moments of the ion density p(z) in terms of other properties (bulk pressure and temperature derivative of surface tension). The Poisson-Boltzmann functional is considered in detail. We show that the first and second …
General Correction For Electrode Sphericity In Voltammetry Of Nernstian Systems, Jerry Goodisman
General Correction For Electrode Sphericity In Voltammetry Of Nernstian Systems, Jerry Goodisman
Chemistry - All Scholarship
The current is considered at a stationary reversible spherical electrode whose potential E(t) as a function of time is given, such that E(t) determines the ratio of oxidized to reduced species at the electrode surface. Writing the current as that for planar geometry, I0, plus corrections for sphericity, we derive formulae for the corrections. The first two are expressed as integrals over I0, with no explicit dependence on the potential, for any form of E(t), and whether the reduced species diffuses into the electrode or into the solution. If the ratio of diffusion constants for oxidized and reduced species is …
Contribution Of The Metal To The Differential Capacity Of An Ideally Polarisable Electrode, Jerry Goodisman, Jean Paul Badiali, Martin Luc Rosinberg
Contribution Of The Metal To The Differential Capacity Of An Ideally Polarisable Electrode, Jerry Goodisman, Jean Paul Badiali, Martin Luc Rosinberg
Chemistry - All Scholarship
We consider the response of the metal in the ideally polarisable electrode to charging of the electrode, using a model for the metal surface in contact with the solvent of the electrolyte phase previously presented by us in this journal. We show that the effect of the solvent on the electrons of the metal cannot be considered to be simply that of a repulsive barrier. When the electrode charge varies, qM(dip), the metal contribution to the double layer, is modified, implying a contribution which varies along the electrocapillary curve. By considering an electrostatic interaction between metal and solvent, we find …
Flow Injection Calibration Methods For Atomic Absorption Spectrometry, Julian Tyson
Flow Injection Calibration Methods For Atomic Absorption Spectrometry, Julian Tyson
Chemistry Department Faculty Publication Series
No abstract provided.