Purification and properties of the hydroxylase component of methane monooxygenase.

AUTOR(ES)

Patel, R N

RESUMO

Methane monooxygenase from Methylobacterium sp. strain CRL-26 which catalyzes the oxygenation of hydrocarbons was resolved into two components, a hydroxylase and a flavoprotein. An anaerobic procedure was developed for the purification of the hydroxylase to homogeneity. The molecular weight of the hydroxylase as determined by gel filtration was 220,000, and that determined by sedimentation equilibrium analysis was about 225,000. The purified hydroxylase contained three nonidentical subunits with molecular weights of about 55,000, 40,000, and 20,000, in equal amounts as judged by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, indicating that it is an alpha 2 beta 2 gamma 2 protein. Optical absorption spectra revealed peaks near 408 and 280 nm, and fluorescence spectra revealed emission peaks at 490 and 630 nm. The purified hydroxylase contained 2.8 +/- 0.2 mol of iron and 0.5 +/- 0.1 mol of zinc per mol of protein but negligible amounts of acid-labile sulfide. The antisera prepared against the hydroxylase showed cross-reactivity with hydroxylase components in soluble extracts from other methanotrophs.

Documentos Relacionados

• Improved System for Protein Engineering of the Hydroxylase Component of Soluble Methane Monooxygenase
• Purification and molecular characterization of the electron transfer protein of methanesulfonic acid monooxygenase.
• Mechanism of the selective functionalization of saturated hydrocarbons by Gif systems: relationship with methane monooxygenase.
• Anthranilate hydroxylase from Aspergillus niger: new type of NADPH-linked nonheme iron monooxygenase.
• Transformation yields of chlorinated ethenes by a methanotrophic mixed culture expressing particulate methane monooxygenase.