par Schindler, Melvin;Sharon, Nathan;Prieels, Jean-Paul
Référence Biochemical and biophysical research communications, 69, 1, page (167-173)
Publication Publié, 1976-03
Article révisé par les pairs
Résumé : Treatment of human α-lactalbumin with diethylpyrocarbonate at pH 6.1 resulted in reduction of its activity in the lactose synthase assay. Almost complete loss of activity occurred when the molar ratio of reagent to protein was 15:1. Incubation of the modified protein in 20 mM hydroxylamine for 1 h restored its full activity. The loss of activity was correlated with the ethoxyformylation of one of the two histidine residues of human α-lactalbumin, as measured by the change in absorption at 242 nm. Evidence is provided that histidine is the only amino acid residue modified. Examination of the NMR spectrum of the inactivated protein demonstrated the disappearance of one histidine (C-2 proton) peak, which could be assigned to that of His 32. © 1976 Academic Press, Inc.