Nitrate Reductase from Sphagnum Species: Isolation, in vitro Assays and Partial Purification

Abstract

Nitrate reductase (EC 1.6.6.2) has been isolated from 11 Sphagnum (Bryophyta) species and purified up to 500-fold by a procedure involving (NH4)2SO4 precipitation and blue sepharose affinity chromatography. The purest fraction showed a nitrate reductase activity of 7.7 nkat mg protein-1 with NADPH as the electron donor. Beside NADPH and NADH, FMNH2 and - after blue sepharose affinity purification of the enzyme - MVH2 were used as electron donors in different assays.