Soluble, nitrate/nitrite‐inducible cytochrome P‐450 of the fungus, Fusarium oxysporum

Abstract
Both soluble and microsomal fractions of Fusarium oxysporum contain cytochrome P‐450(P‐450). We report here that the P‐450 in the soluble fraction was induced only when nitrate or nitrite was added to the growth medium, whereas the microsomal P‐450 was synthesized regardless of the medium compositions. The reduced‐CO complex of the soluble P‐450 exhibited an absorption spectrum that is different from that of the microsomal counterpart. These results indicate that the soluble P‐450 is distinct from the microsomal species and suggest a novel function for the former P‐450.