Importance of Phytoalexin Tolerance and Detoxification for Pathogenicity. Progress Report, April 1, 1984-January 1, 1985

摘要

Previous studies had demonstrated that pisatin demethylation by N. haematococca is catalyzed by a microsomal cytochrome P-450. Cytochrome P-450 and NADPH-cytochrome c reductase from N. haematococca microsomes were solubilized with sodium cholate and partially purified by chromatography on blue A-agarose and omega -aminohexyl-agarose. The NADPH-cytochrome c reductase, which is an essential component of microsomal cytochrome P-450 dependent reaction, was then purified by chromatography on 2',5'-ADP-agarose to a specific activity of about 16 mu moles/min/mg protein. Upon SDS-polyacrylamide gel electrophoresis, the reductase preparation contained one major band of molecular weight 84,000. The purified reductase can reconstitute demethylase activity of cytochrome P-450 fractions, and appears to be rate-limiting for demethylase activity in microsomal extracts. Rabbit antiserum to the reductase has been obtained and partially characterized with regard to inhibition of reductase enzyme activity and Ouchterlony precipitin reactions. 2 refs. (ERA citation 12:001882)