Production, isolation, purification and functional characterisation of methanobactins (2011)

Author(s): Graham DW, Kim HJ

    Abstract: Aerobic methane-oxidizing bacteria (methanotrophs) have a high conditional need for copper because almost all known species express a copper-containing particulate methane monooxygense (pMMO) for catalyzing the conversion of methane to methanol. This demands a copper homeostatic system that must both supply and satisfy adequate copper for elevated needs while also shielding the cells from copper toxicity. After considerable effort, it was discovered that some methanotrophs produce small peptidic molecules, called methanobactins, which bind copper, mediate copper transport into the cell, and reduce copper toxicity. Unfortunately, isolating, purifying and proving the functionality of these molecules has been challenging. In fact, until very recently, only one complete structure had been reported for methanobactins thus far. As such, there is a desperate need for more studies seeking such molecules. The purpose of this chapter is to describe methods used to isolate and purify the original methanobactin with a published complete structure, which is made by Methylosinus trichosporium OB3b. Methods are also included for assessing the function of such molecules under pseudo-natural conditions such as growth on mineral copper sources. Special emphasis is placed on verifying that isolated molecules are “true” methanobactins because recent work has shown methanotrophs produce other small molecules that also bind metals in solution.

      • Book Title: Methods in Methane Metabolism, Part B: Methanotrophy
      • Volume: 495
      • Pages: 227-245
      • Publisher: Academic Press
      • Publication type: Book chapter
      • Bibliographic status: Published

        Professor David Graham
        Professor of Environmental Engineering