American Chemical Society, Journal of the American Chemical Society, 38(134), p. 15660-15663, 2012
DOI: 10.1021/ja306777w
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Methylphosphonate synthase is a non-heme iron-dependent oxygenase that converts 2-hydroxyethylphosphonate (2-HEP) to methylphosphonate. On the basis of experiments with two enantiomers of a substrate analog, 2-hydroxypropylphosphonate, catalysis is proposed to commence with stereospecific abstraction of the pro-S hydrogen on C2 of the substrate. Experiments with isotopologues of 2-HEP indicate stereospecific hydrogen transfer of the pro-R hydrogen at C2 of the substrate to the methyl group of methylphosphonate. Kinetic studies with these substrate isotopologues reveal that neither hydrogen transfer is rate limiting under saturating substrate conditions. A mechanism is proposed that is consistent with the available data.