Nitrite reductase inDunaliella tertiolecta: Isolation and properties

摘要

1. A soluble nitrite reductase has been isolated from cell-free preparations ofDunaliella tertiolectaand purified fifty fold.2. The enzyme resembles nitrite reductases isolated from higher plants in that it is a ferredoxin-nitrite reductase, but differs in that it will not accept electrons from either NADH or NADPH even if exogenous diaphorase is added.3. TheKmvalue for nitrite is 1.1×10−4Mand the molecular weight as determined by chromatography on G-200 Sephadex is 70,000.4. The rates of nitrite reduction obtainedin vitro, using the dithionite-viologen electron donor system are sufficient to account for thein vivorates of nitrate and nitrite assimilation observed in this speci