Optimization of Solubilization and Purification Procedures for the Hydroxylase Component of Membrane-Bound Methane Monooxygenase from Methylococcus capsulatus strain M

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V. I. Vasil'ev¹, T. V. Tikhonova^1*, R. I. Gvozdev², I. A. Tukhvatullin², and V. O. Popov¹

¹Bach Institute of Biochemistry, Russian Academy of Sciences, Leninsky pr. 33, Bld. 2, 119071 Moscow, Russia; fax: (495) 954-2732; E-mail: inbi@inbi.ras.ru; ttikhonova@inbi.ras.ru

²Institute of Problems of Chemical Physics, Russian Academy of Sciences, pr. Akademika Semenova 1, 142432 Chernogolovka, Russia; fax: (09652) 496-76

^* To whom correspondence should be addressed.

Received July 21, 2006; Revision received August 17, 2006

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The hydroxylase component of membrane-bound (particulate) methane monooxygenase (pMMO) from Methylococcus capsulatus strain M was isolated and purified to homogeneity. The pMMO molecule comprises three subunits of molecular masses 47, 26, and 23 kD and contains three copper atoms and one iron atom. In solution the protein exists as a stable oligomer of 660 kD with possible subunit composition (alphabetagamma)₆. Mass spectroscopy shows high homology of the purified protein with methane monooxygenase from Methylococcus capsulatus strain Bath. Pilot screening of crystallization conditions has been carried out.

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KEY WORDS: particulate methane monooxygenase, isolation, purification, activity assay

DOI: 10.1134/S0006297906120078

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