Human endothelial nitric-oxide synthase (eNOS) was expressed in the methylotrophic yeast
Pichia pastoris, making use of the highly inducible alcohol oxidase promoter. The
recombinant protein constituted approximately 3% of total protein and was largely soluble (>
75%). About 1 mg of purified eNOS was obtained from 100-ml yeast cell cultures by affinity
chromatography of crude cell supernatants. The purified enzyme had aV max of 192±18
nmol ofl-citrulline× mg− 1× min− 1, had a K m forl-arginine of 3.9±0.2 μm, and showed an …