Screening, purification, and identification of the enzyme producing N-(l-α-l-aspartyl)-l-phenylalanine methyl ester from l-isoasparagine and l-phenylalanine methyl ester

Screening was carried out for microorganisms able to produce N-(l-α-l-aspartyl)-l-phenylalanine methyl ester [APM] from l-isoasparagine and l-phenylalanine methyl ester hydrochloride. Of the 422 strains examined, 44 strains belonging to the family Enterobacteriaceae were found to produce APM. The enzyme catalyzing APM production was purified and identified as dipeptidase E.