A 60-66 kDa protein with gonadotrophin surge attenuating factor bioactivity is produced by human ovarian granulosa cells.

We aimed to confirm the ovarian site of gonadotrophin surge-attenuating factor (GnSAF) production and produce granulosa/luteal cell-conditioned medium (G/LCM) containing GnSAF for purification studies. Blue dye affinity chromatography followed by pseudochromatofocusing of G/LCM yielded bioactive fractions at pH 5.74 and 5.

A catalase from Streptomyces coelicolor A3(2).

Catalase was purified from the Gram-positive bacterium Streptomyces coelicolor A3(2) in a three-step purification procedure comprising (NH4)2SO4 fractionation, Phenyl-Sepharose chromatography and Mono Q chromatography. The purification of catalase, as judged by the final specific activity of 110,000 U mg-1, was 250-fold with a 35% yield. The native protein was a homotetramer with a subunit M(r) 55,000.