Investigation of the copper center of membrane-bound methane monooxygenase from subcellular structures of Methylococcus capsulatus (Strain M)
UNSPECIFIED. (1996) Investigation of the copper center of membrane-bound methane monooxygenase from subcellular structures of Methylococcus capsulatus (Strain M). BIOCHEMISTRY-MOSCOW, 61 (7). pp. 886-891. ISSN 0006-2979Full text not available from this repository.
Membranes from M. capsulatus (strain M) contain a membrane-bound methane monooxygenase (pMMO) which catalyzes oxidation of CH4 to CH3OH. The enzyme is inactivated by the complexing agent diethyldithiocarbamate (DDTC). Addition of Cu2+ completely reactivates the enzyme. High Cu2+ concentrations irreversibly inactivate pMMO; Fe2+, Mn2+, and Ni2+ do not reactivate pMMO. The DDTC-Cu2+ complex of the pMMO active center can be extracted from lyophilized membranes using acetone. By thin-layer chromatography, HPLC, and absorption spectroscopy it is identical to synthetic DDTC-Cu2+ complex. The pMMO activity is inhibited by 5 mM imidazole and is reactivated only by Cu2+. The pMMO in Cu2+-depleted membrane is not reactivated after addition of the extracted complex. However addition of Cu2+ to these membranes restored 10% of the activity of the initial membrane preparation. Cu2+ may be contained in the pMMO active site; it forms a complex with the protein via histidine residues and is located near the surface of the protein globule. The copper center of pMMO may participate in electron transport or in regulation of pMMO activity or in both processes simultaneously.
|Item Type:||Journal Article|
|Subjects:||Q Science > QD Chemistry|
|Journal or Publication Title:||BIOCHEMISTRY-MOSCOW|
|Publisher:||PLENUM PUBL CORP|
|Official Date:||July 1996|
|Number of Pages:||6|
|Page Range:||pp. 886-891|
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