1.7.1.15	ammonium sulfate precipitation	
1.7.1.15	DEAE-cellulose column chromatography	
1.7.1.15	Ni-NTA column chromatography	
1.7.1.15	purified in the presence of 1 mM NO2- and 0.01 mM FAD by ammonium sulfate precipitation, DEAE-cellulose column chromatography, DEAE-Sephadex gel filtration, and Sephadex G-25 gel filtration