OXIDATION OF REDUCED DIPHOSPHOPYRIDINE NUCLEOTIDE BY CLOSTRIDIUM PERFRINGENS

Abstract

The 4 electron re-duced diphosphopyridine nucleotide (DPN) oxidase of C. perfringens was purified to a turnover (moles of reduced DPN oxidized/minute/M of bound flavin) of 4500 with O2 as oxidant and 3700 with cytochrome c as electron acceptor. One-half of the bound flavin of the enzyme is flavinadenine dinucleotide. Electrophoretic data strongly suggest that the reduced DPN oxidase and cytochrome c reductase activities are carried on the same protein and that spontaneous or irradiation induced (near UV) loss of oxidase activity leads to conversion of the native enzyme to a cytochrome c reductase devoid of oxidase activity. The altered enzyme has different physical properties from the original, native oxidase and in addition has undergone some change in catalytic properties at the active site for cytochrome c reductase activity.