Alkylation of isocitrate lyase from Escherichia coli by 3-bromopyruvate.
The inactivation of tetrameric isocitrate lyase from Escherichia coli by 3-bromopyruvate, exhibiting saturation kinetics, is accompanied by the loss of one sulfhydryl per subunit. The substrates glyoxylate and isocitrate protect against inactivation whereas the substrate succinate does not. The modification by 3-bromopyruvate (equimolar to subunits) imparts striking resistance to digestion of isocitrate lyase by trypsin, chymotrypsin, and V8 protease as well as a major decrease in the intensity of tryptophan fluorescence. After alkylation, the sequence Gly-His-Met-Gly-Gly-Lys is found following the modified Cys residue in the tryptic peptide representing positions 196-201. Thus Cys195 is alkylated by 3-bromopyruvate.
Ko
Y H
YH
Biochemistry/Biophysics Program, Washington State University, Pullman 99164-4660.
McFadden
B A
BA
D000345:Affinity Labels; D000478:Alkylation; D000595:Amino Acid Sequence; D004789:Enzyme Activation / Q000187:drug effects; D004926:Escherichia coli / Q000187:drug effects / Q000201:enzymology*; D006038:Glyoxylates / Q000494:pharmacology*; D007522:Isocitrate Lyase / Q000378:metabolism*; D007700:Kinetics; D008969:Molecular Sequence Data; D007652:Oxo-Acid-Lyases / Q000378:metabolism*; D011773:Pyruvates / Q000494:pharmacology*; D013379:Substrate Specificity
D000345:Affinity Labels; D006038:Glyoxylates; D011773:Pyruvates; C017092:bromopyruvate; D007652:Oxo-Acid-Lyases; D007522:Isocitrate Lyase