Premium
Purification and characterization of the cystinyl bond cleaving yeast aminopeptidase yscXVI
Author(s) -
Tisljar Ursula,
Wolf Dieter H.
Publication year - 1993
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/0014-5793(93)81566-i
Subject(s) - aminopeptidase , chromatofocusing , yeast , substrate (aquarium) , enzyme , hydrolysis , chemistry , biochemistry , chromatography , amino acid , biology , leucine , size exclusion chromatography , ecology
Aminopeptidase yscXVI was purified from the yeast Saccharomyces cerevisiae . By SDS‐PAGE the enzyme has a molecular weight of 45,000 Da, and in chromatofocusing, elution was observed at pH 6.2. The synthetic substrate cystinyl‐4‐nitroanilide ( K m 22.5μM, V max 12.9 mU/mg) is cleaved most efficiently in the pH range 7–8. Besides cleaving this standard substrate, aminopeptidase yscXVI acts on several other 4‐nitroanilide substrates with unsubstituted N‐terminal l ‐amino acids. Highest hydrolysis rate was measured with Lys‐4‐nitroanilide and Leu‐4‐nitroanilide. The activity of aminopeptidase yscXVI is abolished by chelating agents and restored by Zn 2+ , Mn 2+ and Co 2+ ions. Bestatin and amastatin are both strong inhibitors of the enzyme, with K i values of 0.53μM and 0.93μM, respectively. Aminopeptidase yscXVI is detectable in the logarithmic growth phase, stationary phase, and in starved cultures of yeast.