Active-Site Engineering of Benzaldehyde Lyase Shows That a Point Mutation Can Confer Both New Reactivity and Susceptibility to Mechanism-Based Inhibition

作者：Brandt Gabriel S; Kneen Malea M; Petsko Gregory A; Ringe Dagmar; McLeish Michael J^*

来源：Journal of the American Chemical Society, 2010, 132(2): 438-+.

DOI：10.1021/ja907064w

Benzaldehyde lyase (BAL) from Pseudomonas putida is a thiamin diphosphate (ThDP)-dependent enzyme that catalyzes the breakdown of (R)-benzoin. Here we report that a point mutant, BAL A28S, not only catalyzes the decarboxylation of benzoylformate but, like benzoylformate decarboxylase (BFDC), is also inactivated by the benzoylformate analogues methyl benzoylphosphonate (MBP) and benzoylphosphonate (BP). The latter has no effect on wild-type BAL, and the inactivation of the A28S variant is shown to result from phosphorylation of the newly introduced serine residue. This lends Support to the proposal that an appropriately placed nucleophile facilitates the expulsion of carbon dioxide from the active site in many ThDP-dependent decarboxylases.

• 出版日期2010-1-20