An ADP-ribosyltransferase from bovine erythrocytes apparently specific for cysteine residues.
An NAD+:cysteine glycohydrolase purified from bovine erythrocytes had a specific activity of 1900 (nmol nicotinamide released).min-1.mg-1, a K(m) for cysteine of 4.0 mM, and an M, of 45,000. The enzyme also catalysed the dose-dependent ADP-ribosylation of several bovine erythrocyte proteins, including a doublet of high M(r) and proteins of M(r) 60,000, 55,000, and 29,000. ADP-ribosylation of the M(r) 55,000 protein was blocked by pre-treatment of the erythrocyte membranes with N-ethylmaleimide, and ADP-ribose was released by treatment with mercuric ions, but not with hydroxylamine. The enzyme therefore appears to be a cysteine-specific ADP-ribosyltransferase.
van Heyningen
S
S
Department of Biochemistry, University of Edinburgh, Great Britain.
Saxty
B A
BA
D000246:Adenosine Diphosphate Ribose / Q000378:metabolism; D000818:Animals; D002417:Cattle; D003545:Cysteine / Q000378:metabolism*; D004791:Enzyme Inhibitors / Q000494:pharmacology; D004912:Erythrocytes / Q000201:enzymology*; D005033:Ethylmaleimide / Q000494:pharmacology; D009243:NAD / Q000378:metabolism; D009244:NAD+ Nucleosidase / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism*; D011065:Poly(ADP-ribose) Polymerases / Q000378:metabolism*; D013379:Substrate Specificity
D004791:Enzyme Inhibitors; D009243:NAD; D000246:Adenosine Diphosphate Ribose; D011065:Poly(ADP-ribose) Polymerases; D009244:NAD+ Nucleosidase; D003545:Cysteine; D005033:Ethylmaleimide