Isolation and Characterization of Aminopeptidase (Jc-peptidase) from Japanese Cedar Pollen (Cryptomeria japonica)

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• 作者：Yukinori Noguchi ; Hiroyuki Nagata ; Hajime Koganei ; Yoh Kodera ; Misao Hiroto ; Hiroyuki Nishimura ; Yuji Inada ; and Ayako Matsushima
• 刊名：Journal of Agricultural and Food Chemistry
• 出版年：2002
• 出版时间：June 5, 2002
• 年：2002
• 卷：50
• 期：12
• 页码：3540 - 3543
• 全文大小：48K
• 年卷期：v.50,no.12(June 5, 2002)
• ISSN：1520-5118

文摘

An aminopeptidase, Jc-peptidase, was purified from Japanese cedar pollen by seven steps, includingprecipitation with ammonium sulfate, ion-exchange chromatography, gel filtration, hydrophobicinteraction chromatography on phenyl-agarose, and high-performance liquid chromatography. PurifiedJc-peptidease has a molecular weight of 42 kDa and hydrolyzes the synthetic substrates ofL-phenylalanyl-4-methylcoumaryl-7-amide (Phe-MCA) with K_m = 5 × 10^-5 M, Tyr-MCA with K_m = 7× 10^-4 M, Leu-MCA with K_m = 1 × 10^-3 M, and Met-MCA with K_m = 1 × 10^-3 M. Other MCAanalogues such as Arg-MCA or Glu-MCA failed to serve as its substrates. The activity was inhibitedin the presence of phebestin, [(2S,3R)-3-amino-2-hydroxy-4-phenylbutanoyl-L-valyl]-L-phenylalanine,with K_i = 4.7 × 10^-5 M, or bestatin, [(2S,3R)-3-amino-2-hydroxy-4-phenylbutanoyl]-L-leucine, with K_i= 1.1 × 10^-4 M. According to amino acid sequence analysis, the N-terminal amino group seems tobe blocked. The physiological function of the aminopeptidase (Jc-peptidase) has not been clarifiedin vivo.Keywords: Japanese cedar pollen; Cryptomeria japonica pollen; aminopeptidase