Purification and properties of a cytochrome P-450 of a fungus, Fusarium oxysporum

Abstract

A cytochrome P-450 was isolated from a fungus, Fusarium oxysporum, which grew on a medium containing soybean oil as a sole carbon source. It was found as a heme protein that possess lipoxygenase activity, and seemed to exist in the soluble fraction of cell-free extracts. The cytochrome revealed multiplicity and could be separated into a least 3 fractions (A, B, and C). Two of them, termed Fusarium P-450A and -B, were highly purified. The complex of the ferrous Fusarium P-450 with carbon monoxide showed a Soret peak at 447 nm. The properties of the cytochromes (P-450A and -b) were closely similar to each other, the only detectable difference being in the pI (isoelectric point) value (5.2 and 5.0, respectively). The pI and molecular weight (48,000) values together with amino acid composition of Fusarium P-450 were similar to those of other cytochromes P-450 from various sources. Some other spectral properties as well as interactions with various ligands were also studied. Peroxidase or chloroperoxidase activity was not detected with Fusarium P-450.