title: Purification and some properties of NAD-degrading purine nucleosidase from Aspergillus niger.
abstract: An enzyme which degrades NAD at the adenine-ribose linkage has been purified from the mycelial extract of Aspergillus niger. NADP, deamido-NAD, and purine nucleosides and nucleotides were also susceptible to the hydrolytic cleavage. Pyrimidine- and nicotinamide-ribose linkages were not attacked. The substrate specificity showed that the enzyme may be classified as  a N-ribosyl-purine ribohydrolase (EC 3.2.2.1). The enzyme had a maximum activity in the pH range of 4.0-4.5 toward NAD. The Km values for NAD, 5'-AMP, and inosine were 3.0, 2.9 and 1.6mM respectively.
mesh_terms: D001234:Aspergillus niger / Q000201:enzymology*; D008970:Molecular Weight; D009244:NAD+ Nucleosidase / Q000302:isolation & purification / Q000378:metabolism*; D013379:Substrate Specificity
chemical_list: D009244:NAD+ Nucleosidase