Methanotrophic bacteria utilize methane as their sole carbon and energy source. The first step in their metabolic pathway is the oxidation of methane to methanol by methane monooxygenase (MMO) enzyme systems. All but one genus of methanotrophs produce a membrane-bound, copper-containing enzyme called particulate methane monooxygenase (pMMO). Although pMMO is the predominant methane oxidation catalyst in nature, it has proved difficult to isolate, and most investigators have instead opted to study soluble methane monooxygenase (sMMO), a diiron carboxylate-bridged enzyme that is more tractable, but less universal, than pMMO. The structure and mechanism of pMMO and the homologous enzyme ammonia monooxygenase (AMO) remain one of the major unsolved problems in bioinorganic chemistry. Understanding how pMMO activates O2 for oxidation of methane and other hydrocarbons is the long term goal of this research program. Despite the availability of a crystal structure and extensive spectroscopic data, key questions regarding the metal content and active site identity remain unanswered. These issues are of fundamental importance to bioinorganic copper chemistry and have implications for the use of methanotrophs in bioremediation. In addition, methanotrophs play a key role in the global carbon cycle and could help mitigate the deleterious effects of global warming on human health. The proposed research involves purification and characterization of pMMO and AMO from multiple organisms. State-of-the-art crystallization techniques for membrane proteins will be applied to these enzymes. In addition, expression systems will be developed to enable site-directed mutagenesis experiments. Finally, in vitro enzyme activity will be optimized and mechanistic studies initiated.
Bacteria that consume methane gas play an important role in mitigating global warming, which has deleterious effects on human health. These bacteria also are useful for bioremediation of soil and water polluted with hydrocarbon carcinogens. This project will investigate the details of how these bacteria transform methane into methanol.
Ro, Soo Y; Ross, Matthew O; Deng, Yue Wen et al. (2018) From micelles to bicelles: Effect of the membrane on particulate methane monooxygenase activity. J Biol Chem 293:10457-10465 |
Ross, Matthew O; Rosenzweig, Amy C (2017) A tale of two methane monooxygenases. J Biol Inorg Chem 22:307-319 |
Lawton, Thomas J; Kenney, Grace E; Hurley, Joseph D et al. (2016) The CopC Family: Structural and Bioinformatic Insights into a Diverse Group of Periplasmic Copper Binding Proteins. Biochemistry 55:2278-90 |
Kenney, Grace E; Goering, Anthony W; Ross, Matthew O et al. (2016) Characterization of Methanobactin from Methylosinus sp. LW4. J Am Chem Soc 138:11124-7 |
Trana, Ethan N; Nocek, Judith M; Woude, Jon Vander et al. (2016) Charge-Disproportionation Symmetry Breaking Creates a Heterodimeric Myoglobin Complex with Enhanced Affinity and Rapid Intracomplex Electron Transfer. J Am Chem Soc 138:12615-28 |
Lawton, Thomas J; Rosenzweig, Amy C (2016) Methane-Oxidizing Enzymes: An Upstream Problem in Biological Gas-to-Liquids Conversion. J Am Chem Soc 138:9327-40 |
Lawton, Thomas J; Rosenzweig, Amy C (2016) Biocatalysts for methane conversion: big progress on breaking a small substrate. Curr Opin Chem Biol 35:142-149 |
Blanchette, Craig D; Knipe, Jennifer M; Stolaroff, Joshuah K et al. (2016) Printable enzyme-embedded materials for methane to methanol conversion. Nat Commun 7:11900 |
Rosenzweig, Amy C (2015) Biochemistry: Breaking methane. Nature 518:309-10 |
Sirajuddin, Sarah; Rosenzweig, Amy C (2015) Enzymatic oxidation of methane. Biochemistry 54:2283-94 |
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