Yeast aminopeptidase I, when purified from autolysates of brewer's yeast, is obtained in two molecular froms a) the enzymatically active dodecameric complex (Mr = 640,000, s20,w = 22 S) and b) inactive hexamers (Mr = 320,000, s20,w = 12 S). Although the amino acid composition of the 12 S protein is very similar to that of the active enzyme,the hexamers behave differently in ionic exchange chrom...

Leucine aminopeptidase and aminopeptidase M have been covalently bound to an arylamine derivative of porous glass. The bound forms of both enzymes retain 100% of their activities at saturating levels of substrate (leucine p-nitroanilide). For the hydrolysis at pH 7.3 and 25” kcat values for bound and free leucine aminopeptidase are 46 & 5 s-l and 46 + 2 s-l, respectively; for aminopeptidase M (...