title: An NAD:cysteine ADP-ribosyltransferase is present in human erythrocytes.
abstract: A novel enzymatic activity, i.e., the catalysis of the formation of ADP-ribosylcysteine, was found in the cytosol of human erythrocytes. The NAD:cysteine ADP-ribosyltransferase was partially purified by sequential chromatographic steps on phenyl-Sepharose, phosphocellulose, and Sepharose CL-6B. The enzyme has an apparent molecular weight of 27,000 +/- 3,000, as determined by gel permeation. The formation of ADP-ribosylcysteine was associated with the stoichiometric release of nicotinamide from NAD. The enzyme was found to be highly specific toward cysteine and cysteine methyl ester as ADP-ribose acceptors. S-Benzoyl-L-cysteine, cystine, histidine, glutamic acid, arginine, arginine methyl ester, and agmatine were ineffective as acceptors for this enzyme.
mesh_terms: D000244:Adenosine Diphosphate / Q000378:metabolism; D002850:Chromatography, Gel; D004912:Erythrocytes / Q000201:enzymology*; D006801:Humans; D008970:Molecular Weight
chemical_list: D000244:Adenosine Diphosphate