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Biomedical subjects

C V Grant

Publications and source records attributed to C V Grant.

8 recordsLinked to original sources

NMR experiments on aligned samples of membrane proteins.

NMR methods can be used to determine the structures of membrane proteins. Lipids can be chosen so that protein-containing micelles, bicelles, or bilayers are available as samples. All three types of samples can be aligned weakly or strongly, depending on their rotational correlation time. Solution NMR methods can be used with weakly aligned micelle and small bicelle samples. Solid-state NMR methods can be used with mechanically aligned bilayer and magnetically aligned bicelle samples.

Electrophoresis, Polyacrylamide Gel↗

Peptides and the development of double- and triple-resonance solid-state NMR of aligned samples.

Peptides have been instrumental in the development of solid-state nuclear magnetic resonance (NMR) spectroscopy, and their roles in the development of solid-state NMR of aligned samples is reviewed. In particular, the roles of synthetic peptides in the development of triple-resonance methods are described. Recent developments of pulse sequences and NMR probes for triple-resonance NMR of aligned samples are presented.

Magnetic Resonance Spectroscopy↗

ESEEM studies of succinate:ubiquinone reductase from Paracoccus denitrificans.

Electron spin-echo envelope modulation (ESEEM) spectroscopy has been performed in order to obtain structural information about the environment of the reduced [2Fe-2S] cluster (S-1 center), the oxidized [3Fe-4S] cluster (S-3 center), and the flavin semiquinone radical in purified succinate:ubiquinone reductase from Paracoccus denitrificans. Spectral simulations of the ESEEM data from the reduced [2Fe-2S] yielded nuclear quadrupole interaction parameters that are indicative of peptide nitrogens. We also observed a weak interaction between the oxidized [3Fe-4S] cluster and a peptide 14N. There was no evidence for coordination of any of the Fe atoms to 14N atoms of imidazole rings. The ESEEM data from the flavin semiquinone radical were more complicated. Here, evidence was obtained for interactions between the unpaired electron and only the two nitrogen atoms in the flavin ring.

Animals↗

Electronic Structure of the Aqueous Vanadyl Ion Probed by 9 and 94 GHz EPR and Pulsed ENDOR Spectroscopies and Density Functional Theory Calculations.

The aqueous vanadyl ion ([VO(H(2)O)(5)](2+)) has been investigated by X-band EPR, 94 GHz W-band EPR, and ESE-ENDOR. These experiments reveal information about the hyperfine (|A(xx)| = 208.5 MHz, |A(yy)| = 208.5 MHz, |A(zz)| = 547.0 MHz), and nuclear quadrupole coupling (|e(2)qQ| = 5.6 MHz) of the (51)V nucleus. The measured nuclear quadrupole coupling parameters are compared to values determined by density functional theory calculations (|e(2)qQ| = 5.2 MHz). These theoretical calculations illustrate that axial ligands and molecular distortions can alter the magnitude of the nuclear quadrupole interaction.

Journal Article↗

Automated preference testing apparatus for rating palatability of foods.

An electronic preference testing apparatus is described for measuring taste preference of rodents and other small animals with solid or liquid foods. The apparatus is designed on the principle of the two-choice, preference technique. It operates photoelectrically with a sequence of presentations so that whenever a subject eats from a compartmentalized food tray, a standard and a test food are each briefly sampled alone before both foods are presented together (in alternate positions) for preference determination. Preferences are automatically recorded on digital counters. The apparatus is built in two modules (a preference tester and the master control) connected by multiconductor cable. The modular design provides portability and isolation of the animals from the major noise-producing components. Diagrams of the apparatus are given, and test results from a trial that evaluated positional bias and a sucrose-concentration preference experiment are presented to demonstrate its application in research.

Animals↗