L Haeffner-Gormley

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Wild-type glutamate dehydrogenase (EC from Salmonella typhimurium reacts at 25 degrees C in 0.1 M phosphate buffer, pH 7, with the nucleotide analogue 2-[(4-bromo-2,3-dioxobutyl)thio]-adenosine 2',5'-bisphosphate (2-BDB-TA 2',5'-DP) to give 78% inactivation. Protection against inactivation was achieved with NADPH, indicating that modification(More)
Affinity labeling studies of NADP(+)-glutamate dehydrogenase from Salmonella typhimurium have shown that the peptide Leu-282-Lys-286 is located near the coenzyme site [Haeffner-Gormley et al. (1991) J. Biol. Chem. 266, 5388-5394]. The present study was undertaken to evaluate the role of lysine-286. The mutant enzymes K286R, K286Q, and K286E were prepared by(More)
S-2-Br-hexanoyl-CoA and the branched chain isomer S-2-Br-4-methyl-pentanoyl-CoA are affinity labels of the medium-chain acyl-CoA dehydrogenase from pig kidney. The straight chain thioester is both a substrate and an irreversible inhibitor of the dehydrogenase. Inactivation of the enzyme is biphasic and is half-complete in 4 min at pH 6.5, 25 degrees C.(More)
NADP(+)-specific glutamate dehydrogenase of Salmonella typhimurium was previously shown to react irreversibly at the coenzyme site with the nucleotide analogue 2-((4-bromo-2,3-dioxobutyl)thio)-1,N6-ethenoadenosine 2',5'-bisphosphate (2-BDB-T epsilon A 2',5'-DP) yielding a partially active enzyme, and inactivation was attributed to modification of the(More)
The disulfide peptides from the tryptic digestion of cyanogen bromide-treated hen egg white lysozyme (HEWL) were isolated by reverse phase high performance liquid chromatography (HPLC) and identified by amino acid analysis. Three peptides containing the I-VIII, II-VII, and III-V + IV-VI disulfide bonds were obtained. The two-disulfide peptide was further(More)
A range of 4-thiaacyl-CoA derivatives has been synthesized to study the bioactivation of cytotoxic fatty acids by the mitochondrial medium-chain acyl-CoA dehydrogenase and the peroxisomal acyl-CoA oxidase. Both enzymes catalyze alpha-proton abstraction from normal acyl-CoA substrates with elimination of a beta-hydride equivalent to the FAD prosthetic group.(More)
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