Chemical modification of tyrosine residues in glyoxalase I from yeast and human erythrocytes.
1. Yeast glyoxalase I was inactivated by N-acetylimidazole and tetranitromethane, the latter process following pK app 7.31 and irreversibly producing a protein with a spectrum typical of 3-nitrotyrosine. 2. For yeast glyoxalase I, amino-acid analysis and protection studies with S-(p-bromobenzyl)glutathione, a competitive inhibitor, indicated two classes of tetranitromethane-reactive tyrosine residues, fast- and slow-reacting, with the latter class containing the crucial tyrosine(s). 3. Human erythrocyte glyoxalase I was inactivated by tetranitromethane in fast and slow processes, protection studies in this case indicating the important tyrosine(s) as fast-reacting.
Carrington
S J
SJ
Department of Pharmacy, University of Manchester, England.
Fetherbe
D
D
Douglas
K T
KT
D000596:Amino Acids / Q000032:analysis; D055598:Chemical Phenomena; D002621:Chemistry; D004912:Erythrocytes / Q000201:enzymology*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007093:Imidazoles; D007791:Lactoylglutathione Lyase / Q000037:antagonists & inhibitors / Q000097:blood / Q000378:metabolism*; D008190:Lyases / Q000378:metabolism*; D012441:Saccharomyces cerevisiae / Q000201:enzymology*; D013053:Spectrophotometry; D013774:Tetranitromethane; D014443:Tyrosine / Q000378:metabolism*
D000596:Amino Acids; D007093:Imidazoles; D014443:Tyrosine; D008190:Lyases; D007791:Lactoylglutathione Lyase; D013774:Tetranitromethane; C012160:N-acetylimidazole