Oxidation of acetylpolyamines by extracellular polyamine oxidase produced by Penicillium sp. No. PO-1.

The oxidation of acetylpolyamines by an extracellular polyamine oxidase of Penicillium sp. No. PO-1 was investigated. The optimal pH value for oxidation of acetylpolyamines was 6.0. The purified enzyme oxidized spermidine, spermine, N1-acetylspermidine, N8-acetylspermidine, N1,8-diacetylspermidine, N1-acetylspermine and N1,12-diacetylspermine. The relative velocities for oxidation of acetylpolyamines were lower than those of spermidine and spermine. The Km values for oxidation of acetylpolyamines were higher than those of spermidine and spermine. The enzyme split N1-acetylspermidine and N8-acetylspermidine at the same position of the linkage as in spermidine oxidation. N1-Acetylspermine was changed to N1-acetylspermidine. This oxidation mechanism was different from that of rat liver polyamine oxidase. N1-Acetylspermine inhibited the oxidation of spermine. Putrescine, N8-acetylspermidine and N1,12-diacetylspermine also inhibited the N1-acetylspermidine oxidation by the enzyme.