The terminal enzymes of sialic acid metabolism: Acylneuraminate pyruvate-lyases

The acyneuraminate pyruvate-lyase gene from Clostridium perfringens was seq uenced and found to be most similar to the lyase gene from Haemophilus infl uenzae. Both the recombinant clostridial enzyme and the native enzyme from pig kidney were purified in larger amounts and characterized. The propertie s of the porcine lyase are similar to the microbial ones. However, the much higher degree of similarity in comparison to the microbial enzymes that wa s found between porcine lyase peptides and two putative mammalian lyase seq uences show that the latter form an own group apart from the microbial lyas es. Actual models of the acylneuraminate pyruvate-lyase reaction are discus sed.