Pyruvyl-dependent amino acid decarboxylases

Pyruvyl-dependent amino acid decarboxylases are mechanistically analogous to the PLP-dependent amino acid decarboxylases wherein a pyruvyl group in amido linkage to the amino terminus of the protein functions in place of PLP. The formation of a Schiff base linkage between the a-amino function of the amino acid and the ketonic carbonyl of the pyruvyl moiety is supported by the results of borohydride trapping experiments with L-histidine decarboxylase Lactobacillus 30a) in the presence of substrate (265). Evidence could not be found for a reducible internal aldimine in the absence of substrate. 

Models were also reported for the pyruvyl-dependent a-amino acid decarboxylases Using a variety of amino acids along with pyruvate or pyruvamide or ethyl pyruvate in DMF leads to decarboxylation via the imine. The putative azomethine ylide... 

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