PURIFICATION AND PROPERTIES OF PARTICULATE METHANE MONOOXYGENASE FROMMETHYLOSINUS-TRICHOSPORIUM OB3B

Particulate methane monooxygenase (pMMO) from Methylosinus trichospori um OB3b has been solubilized with n-dodecyl-beta-D-maltoside and purif ied by chromatographic techniques. The molecular weight was estimated to 326 kDa consisting of two subunits with molecular masses of 25 and 41 kDa. The enzyme contained 0.9 iron atom and 12.8 copper atoms/molec ule. The electron spin resonance (ESR) spectra of the enzyme showed a type II copper (g(parallel to) = 2.24, A(parallel to) = 18.4 mT, g(per pendicular to) = 2.06) and a weak high-spin iron signal (g = 5.98). By treatment of pMMO with duroquinol, dioxygen and acetylene, the iron s ignal disappeared, showing an iron atom is contained in active site of pMMO. (C) 1998 Elsevier Science B.V. All rights reserved.