Methanobactins are peptide-derived, copper-binding molecules secreted by methane-oxidizing bacteria. These environmentally significant copper-scavengers evolved to address the requirement for copper as a cofactor to particulate methane monooxygenase (pMMO), the enzyme in methanotrophs which catalyzes the oxidation of methane to methanol. Here, we focus on the first two methanobactins to be structurally characterized: mb-OB3b, isolated from Methylosinus trichosporium, and mb-SB2, isolated from Methylocystis strain SB2. As isolated, both are associated with various molecular fragments formed through structural modifications such as loss of a terminal amino acid, hydrolysis of the oxazolone ring(s), sulfur oxidation, and peptide-bond cleavage. Systematic isolation and characterization of these fragments reveals differential copper-binding abilities. Our results indicate that the presence of the A- ring system is the minimum structural requirement for binding and reducing Cu2+ ions. These findings suggest methanobactin fragments are produced with a variety of structures and copper-binding abilities, which may have biological significance.

Structural characterization and copper-binding properties of methanobactin derivatives isolated from the methane-oxidizing bacteria <i>Methylosinus trichosporium</i> (mb-OB3b) and <i>Methylocystis strain</i> SB2 (mb-SB2)

245th National Meeting (2013)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.

Structural characterization and copper-binding properties of methanobactin derivatives isolated from the methane-oxidizing bacteria Methylosinus trichosporium (mb-OB3b) and Methylocystis strain SB2 (mb-SB2)