PH dependence of a mammalian polyamine oxidase: insights into substrate specificity and the role of lysine 315.

ABSTRACT: Mammalian polyamine oxidases (PAOs) catalyze the oxidation of N1-acetylspermine and N1-acetylspermidine to produce N-acetyl-3-aminopropanaldehyde and spermidine or putrescine. Structurally, PAO is a member of the monoamine oxidase family of flavoproteins. The effects of pH on the kinetic parameters of mouse PAO have been determined to provide insight into the protonation state of the polyamine required for catalysis and the roles of ionizable residues in the active site in amine oxidation. For N1-acetylspermine, N1-acetylspermidine, and spermine, the k(cat)/K(amine)-pH profiles are bell-shaped. In each case, the profile agrees with that expected if the productive form of the substrate has a single positively charged nitrogen. The pK(i)-pH profiles for a series of polyamine analogues are mo

SUBMITTER: Henderson Pozzi M 

PROVIDER: S-EPMC2752350 | biostudies-literature | 2009 Feb

REPOSITORIES: biostudies-literature