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Structure and reversible pyran formation in molybdenum pyranopterin dithiolene models of the molybdenum cofactor.

ABSTRACT: The syntheses and X-ray structures of two molybdenum pyranopterin dithiolene complexes in biologically relevant Mo(4+) and Mo(5+) states are reported. Crystallography reveals that these complexes possess a pyran ring formed through a spontaneous cyclization reaction of a dithiolene side-chain hydroxyl group at a C?N bond of the pterin. NMR data on the Mo(4+) complex suggest that a reversible pyran ring cyclization occurs in solution. These results provide experimental evidence that the pyranopterin dithiolene ligand in molybdenum and tungsten enzymes could participate in catalysis through dynamic processes modulated by the protein.

SUBMITTER: Williams BR

PROVIDER: S-EPMC3526347 | biostudies-literature | 2012 Dec

REPOSITORIES: biostudies-literature

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Structure and reversible pyran formation in molybdenum pyranopterin dithiolene models of the molybdenum cofactor.

Williams Benjamin R BR Fu Yichun Y Yap Glenn P A GP Burgmayer Sharon J Nieter SJ

Journal of the American Chemical Society 20121120 48

The syntheses and X-ray structures of two molybdenum pyranopterin dithiolene complexes in biologically relevant Mo(4+) and Mo(5+) states are reported. Crystallography reveals that these complexes possess a pyran ring formed through a spontaneous cyclization reaction of a dithiolene side-chain hydroxyl group at a C═N bond of the pterin. NMR data on the Mo(4+) complex suggest that a reversible pyran ring cyclization occurs in solution. These results provide experimental evidence that the pyranopte ...[more]

PMID: 23157708

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