Native top-down mass spectrometry provides insights into the copper centers of membrane-bound methane monooxygenase.

Autor: Ro SY; Departments of Molecular Biosciences and of Chemistry, Northwestern University, 2205 Tech Drive, Evanston, IL, 60208, USA., Schachner LF; Departments of Molecular Biosciences and of Chemistry, Northwestern University, 2205 Tech Drive, Evanston, IL, 60208, USA., Koo CW; Departments of Molecular Biosciences and of Chemistry, Northwestern University, 2205 Tech Drive, Evanston, IL, 60208, USA., Purohit R; Departments of Molecular Biosciences and of Chemistry, Northwestern University, 2205 Tech Drive, Evanston, IL, 60208, USA., Remis JP; Departments of Molecular Biosciences and of Chemistry, Northwestern University, 2205 Tech Drive, Evanston, IL, 60208, USA., Kenney GE; Departments of Molecular Biosciences and of Chemistry, Northwestern University, 2205 Tech Drive, Evanston, IL, 60208, USA., Liauw BW; Departments of Molecular Biosciences and of Chemistry, Northwestern University, 2205 Tech Drive, Evanston, IL, 60208, USA., Thomas PM; Departments of Molecular Biosciences and of Chemistry, Northwestern University, 2205 Tech Drive, Evanston, IL, 60208, USA., Patrie SM; Departments of Molecular Biosciences and of Chemistry, Northwestern University, 2205 Tech Drive, Evanston, IL, 60208, USA., Kelleher NL; Departments of Molecular Biosciences and of Chemistry, Northwestern University, 2205 Tech Drive, Evanston, IL, 60208, USA. n-kelleher@northwestern.edu., Rosenzweig AC; Departments of Molecular Biosciences and of Chemistry, Northwestern University, 2205 Tech Drive, Evanston, IL, 60208, USA. amyr@northwestern.edu.
Jazyk: angličtina
Zdroj: Nature communications [Nat Commun] 2019 Jun 17; Vol. 10 (1), pp. 2675. Date of Electronic Publication: 2019 Jun 17.
DOI: 10.1038/s41467-019-10590-6
Abstrakt: Aerobic methane oxidation is catalyzed by particulate methane monooxygenase (pMMO), a copper-dependent, membrane metalloenzyme composed of subunits PmoA, PmoB, and PmoC. Characterization of the copper active site has been limited by challenges in spectroscopic analysis stemming from the presence of multiple copper binding sites, effects of detergent solubilization on activity and crystal structures, and the lack of a heterologous expression system. Here we utilize nanodiscs coupled with native top-down mass spectrometry (nTDMS) to determine the copper stoichiometry in each pMMO subunit and to detect post-translational modifications (PTMs). These results indicate the presence of a mononuclear copper center in both PmoB and PmoC. pMMO-nanodisc complexes with a higher stoichiometry of copper-bound PmoC exhibit increased activity, suggesting that the PmoC copper site plays a role in methane oxidation activity. These results provide key insights into the pMMO copper centers and demonstrate the ability of nTDMS to characterize complex membrane-bound metalloenzymes.
Databáze: MEDLINE
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