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Dehydrocyclopeptine epoxidase from Penicillium cyclopium

1977; Elsevier BV; Volume: 16; Issue: 11 Linguagem: Inglês

10.1016/0031-9422(71)85063-x

1873-3700

Sabine Voigt, Martin Luckner,

Microbial Natural Products and Biosynthesis

Dehydrocyclopeptine epoxidase (DE) activity was determined in cell free preparations of Penicillium cyclopium. The enzyme transforms dehydrocyclopeptine into cyclopenin by a mixed function oxygenation. It needs molecular oxygen and uses NAD(P)H, ascorbate or d,l-6-methyl-5,6,7,8-tetrahydropteridine as cosubstrates. DE is inhibited by CN−, SCN−, 1,10-phenanthroline, EDTA, 2,2′-bipyridine, sodium diethyldithiocarbamate, dicoumarol, p-chloromercuribenzoate and ions of different heavy metals, but not by CO and the lead salt of diethyldithiocarbamate. These properties indicate a specific importance of Fe2+-ions, SH-groups and flavins. DE activity is increased by Fe2+ and FAD. The enzyme may be therefore a Fe2+ activated FAD containing flavoprotein. DE was enriched 268-fold by (NH4)2SO4 precipitation and chromatography on Sephadex G-200. Its MW estimated by Sephadex chromatography, exceeds 480 000.