[Methane monooxygenases hydroxylase from a type II methanotroph: purification and physical-chemical properties].

Methanotrophs can catalyze hydroxylate of methane and some hydrocarbon. Which play an important role in mitigating global warming and have also potential significance for industrial applications or bioremediation. A high activity of hydroxylase, a crucial component in sMMO, from Methylosinus trichosporium IMV 3011 has been purified to homologues by using chromatographic techniques. The molecular weight of the hydroxylase determined by gel filtration is 201.3 kD, and SDS-PAGE showed that hydroxylase consists of three subunits(alpha beta gamma) with molecular weights of 58kD, 36kD and 23kD respectively, drawing a comparison both methods indicated that the hydroxylase is a homodimer with an (alpha beta gamma)2 configuration. Purified hydroxylase has a pI at 5.2 judged by thin layer isoelectric focusing. The purified hydroxylase contains 3.02 mol of iron per mol of protein. The stability pH for the hydroxylase in solution is 5.8-8.0 and the stability temperature is below 35 degrees C. The cells form show a long, bent, and rod-shaped with even surface observed by scanning electron microscopy.