STABILISIERTE NAD(P)H-ABHAENGIGE LOESLICHE NITRATREDUKTASE, VERFAHREN ZU IHRER HERSTELLUNG UND IHRE VERWENDUNG.

摘要

Stabilised soluble NAD(P)H-dependent assimilatory-type nitrate reductase (I) has a molecular wt. of ca. 90,000 (by SDS electrophoresis), has a residual activity of more than 60% after 3 weeks at 35 deg.C, and is produced by (a) preparing a suspension of comminuted starting material in Tris/tartaric acid (TTA) buffer with a pH of 7-8.5, (b) adding soluble polyethylenimine (PEI) to ppte. 10-20% of the nitrate reductase activity, (c) separating the ppte., (d) fractionating the supernatant in TTA buffer, (e) dialysing the resulting enzyme soln., and (f) freeze drying the prod. in a zwitterionic buffer.