title: The photochemical inactivation of peptidyl transferase activity.
abstract: The photochemical oxidation of the 50-S ribosomal subunit results in a rapid irreversible loss of peptidyl transferase activity. The first-order rate of inactivation occurring during the first forty minutes suggests that a single reactive group is being inactivation exhibits a maximum at pH 7.5. Erythromycin at a low concentration (0.04 mumol) affords significant protection. Puromycin also exerts a protective effect but at higher concentrations. Chloramphenicol, sparsomycin and lincomycin did not exert a protective effect. The loss in catalytic activity was not accompanied by a loss in substrate binding affinity of the donor and acceptor substrates.
mesh_terms: D000217:Acyltransferases / Q000378:metabolism*; D002701:Chloramphenicol / Q000494:pharmacology; D004917:Erythromycin / Q000494:pharmacology; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D008027:Light; D008034:Lincomycin / Q000494:pharmacology; D008623:Mercaptoethanol / Q000494:pharmacology; D010458:Peptidyl Transferases / Q000378:metabolism*; D010649:Phenylalanine; D010777:Photochemistry; D011485:Protein Binding; D011691:Puromycin / Q000494:pharmacology; D012270:Ribosomes / Q000201:enzymology; D012395:Rose Bengal / Q000494:pharmacology; D013033:Sparsomycin / Q000494:pharmacology
chemical_list: D012395:Rose Bengal; D010649:Phenylalanine; D011691:Puromycin; D008623:Mercaptoethanol; D004917:Erythromycin; D002701:Chloramphenicol; D013033:Sparsomycin; D008034:Lincomycin; D000217:Acyltransferases; D010458:Peptidyl Transferases