Mechanistic studies of electron transfer, complex formation, C-H bond activation, and product binding in soluble methane monooxygenase

Chapter 1. Soluble Methane Monooxygenase: Activation of Dioxygen and Methane The mechanisms by which soluble methane monooxygenase uses dioxygen to convert methane selectively to methanol have come into sharp focus. Diverse techniques have clarified subtle details about each step in the reaction, from binding and activating dioxygen, to hydroxylation of alkanes and other substrates, to the electron transfer events required to complete the catalytic cycle. Chapter 2. Electron Transfer Reactions of the Reductase Component of Soluble Methane Monooxygenase from Methylococcus capsulatus (Bath) Soluble methane monooxygenase (sMMO) catalyzes the hydroxylation of methane by dioxygen to afford methanol and water, the first step of carbon assimilation in methanotrophic bacteria. This enzyme comprises three protein components: a hydroxylase (MMOH) that contains a dinuclear non-heme iron active site, a reductase (MMOR) that facilitates electron transfer from NADH to the diiron site of MMOH, and a coupling protein (MMOB). MMOR uses a non-covalently bound FAD cofactor and a [2Fe-2S] cluster to mediate electron transfer. The gene encoding MMOR was cloned from Methylococcus capsulatus (Bath) and expressed in Escherichia coli in high yield. Purified recombinant MMOR was indistinguishable from the native protein in all aspects examined, including activity, mass, cofactor content, and EPR spectrum of the [2Fe-2S] cluster. Redox potentials for the FAD and [2Fe-2S] cofactors, determined by reductive titrations in the presence of indicator dyes ...

Department dc:contributor.department

Massachusetts Institute of Technology. Dept. of Chemistry.

Grantor dc:publisher

Massachusetts Institute of Technology

Year dc:date.issued

2003

Author dc:creator

• Kopp, Daniel Arthur

Advisor dc:contributor.advisor

• Stephen J. Lippard.

• Chemistry.

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• M.I.T. theses are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission. See provided URL for inquiries about permission.

Licence dc:rights.uri

• http://dspace.mit.edu/handle/1721.1/7582

Language dc:language.iso

eng

Handle dc:identifier.uri

http://hdl.handle.net/1721.1/16915

OAI identifier oai:identifier

oai:dspace.mit.edu:1721.1/16915