Details

Autor(en) / Beteiligte

• Yokoyama, Ryo
• Kawasaki, Hiroshi
• Hirano, Hisashi

Titel

Identification of yeast aspartyl aminopeptidase gene by purifying and characterizing its product from yeast cells

Ist Teil von

• The FEBS journal, 2006-01, Vol.273 (1), p.192-198

Ort / Verlag

Oxford, UK: Blackwell Science Ltd

Erscheinungsjahr

2006

Quelle

Wiley Online Library Journals Frontfile Complete

Beschreibungen/Notizen

• Aspartyl aminopeptidase (EC 3.4.11.21) cleaves only unblocked N‐terminal acidic amino‐acid residues. To date, it has been found only in mammals. We report here that aspartyl aminopeptidase activity is present in yeast. Yeast aminopeptidase is encoded by an uncharacterized gene in chromosome VIII (YHR113W, Saccharomyces Genome Database). Yeast aspartyl aminopeptidase preferentially cleaved the unblocked N‐terminal acidic amino‐acid residue of peptides; the optimum pH for this activity was within the neutral range. The metalloproteases inhibitors EDTA and 1.10‐phenanthroline both inhibited the activity of the enzyme, whereas bestatin, an inhibitor of most aminopeptidases, did not affect enzyme activity. Gel filtration chromatography revealed that the molecular mass of the native form of yeast aspartyl aminopeptidase is ≈ 680 000. SDS/PAGE of purified yeast aspartyl aminopeptidase produced a single 56‐kDa band, indicating that this enzyme comprises 12 identical subunits.