Glycine N-acylase

Bartlett K, Gompertz D (1974) The specificity of glycine-N-acylase and acylglycine excretion in the organic acidaemias. Biochem Med 10 15-23... 

The conjugation of glycine with benzoic acid to yield hippurate requires energy and in liver slices is inhibited by cyanide. The reaction occurs in three steps (1) the acylation of benzoic acid in the presence of ATP to yield benzoyl AMP and pyrophosphate (2) the conversion of benzoyl AMP to the coenzyme A derivative and (3) in the presence of a mitochondrial enzyme, the exchange of the coenzyme A moiety of benzoyl AMP with glycine to yield hippurate and coenzyme A. Glycine-N-acylase is the enzyme that catalyzes the transfer. It has been purified from beef liver mitochondria. 

In subsequent process generations, peniciUin G acylase derived enzymes were also used to couple the synthetic side chains, such as D-phenylglycine (ampicillin, cephalexin) and D-p-hydroxyphenylglycine (amoxicillin, cephadroxil) in the form of amino acid amides or esters to 6-APA and 7-ADCA (Scheme 4.6D). Biotransformation routes to the n-phenylglycine and n-p-hydroxyphenylglycine side chains were also developed (Scheme 4.6C), but the enzymatic process towards n-phenyl-glycine amide has been substituted by a classical resolution. 

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