2.6.1.30 | pyridoxamine + pyruvate = pyridoxal + L-alanine |
enzyme first binds pyridoxamine and then forms a Michaelis complex with the incoming pyruvate. The ketimine is formed through nucleophilic attack of the N-4' atom of pyridoxamine on the alpha-carbon atom of pyruvate, which is followed by the release of a water molecule. The stereospecific 1,3-prototropic shift between the ketimine and external aldimine via the quinonoid intermediate is accomplished through general base catalysis by Lys197. Pyridoxal and L-alanine are formed from the external aldimine and released from enzyme |
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