Methylamine dehydrogenase containing covalently bound tryptophan tryptophylquinone （TTQ） as prosthetic group

was purified to homogenity from cell extract of Methylotrophic bacteria No1 with specific activity of 5.1μmol·mg -1 protein.The molecular weight of the enzyme estimated to be 66×10 3 and it was composed of one 36.5×10 3 subunit and two 14.7×10 3 subunits.The enzyme exhibited optimal activity at pH8.0 and two pI values of 8.3 and 8.5

with K m value of 26.6 μm for methylamine.The reaction catalyzed by the enzyme was inhibited by Cu 2+ .The enzyme was stable to thermal denaturation.The absorption spectral of the enzyme showed absorption maxima at 426 nm and a shoulder at around 328 nm.