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瑞士乳杆菌X-脯氨酰-二肽酰基-氨基肽酶的分离纯化及酶学性质

郭宇星1,祝 倩1,朱 坤1,周慧敏1,孙杨赢1,2,曾小群1,2,潘道东1,2,*   

  1. 1.南京师范大学金陵女子学院,江苏 南京 210097;2.宁波大学海洋学院,浙江 宁波 315211
  • 出版日期:2013-09-15 发布日期:2013-09-27
  • 通讯作者: 潘道东
  • 基金资助:

    国家自然科学基金青年科学基金项目(31101314);江苏省自然科学基金项目(BK2011787);
    江苏省高校自然科学基金项目(13KJB550013);南京师范大学特聘教授、高层次人才科研启动基金项目(184070H2B08);
    浙江省自然科学基金项目(LQ12C20003);宁波市科技局创新基金项目(2010C92024);宁波市自然科学基金项目(2012A610145)

Purification and Characterization of X-Prolyl Dipeptidyl Aminopeptidase from Lactobacillus helveticus

GUO Yu-xing1,ZHU Qian1,ZHU Kun1,ZHOU Hui-min1,SUN Yang-ying1,2,ZENG Xiao-qun1,2,PAN Dao-dong1,2,*     

  1. 1. Ginling College, Nanjing Normal University, Nanjing 210097, China;
    2. School of Marine Sciences, Ningbo University, Ningbo 315211, China
  • Online:2013-09-15 Published:2013-09-27
  • Contact: PAN Dao-dong

摘要:

提取并纯化瑞士乳杆菌X-脯氨酰-二肽酰基-氨基肽酶(Pep X),并对其酶学性质进行研究。采用超声波破碎瑞士乳杆菌菌体获得含有Pep X的粗酶液,粗酶液经过硫酸铵沉淀、Sephacryl S-300 HR层析、非变性-聚丙烯酰胺凝胶电泳法切胶回收蛋白纯化瑞士乳杆菌Pep X。纯化后Pep X经SDS-PAGE测定分子质量并研究酶学性质。得到电泳纯的Pep X,酶比活力62.24U/mg,单体分子质量大约26kD,最适酶反应pH7.0,最适酶反应温度37℃。Co2+对Pep X有激活作用,Zn2+、Ni2+、Mn2+、Fe3+对Pep X有强烈的抑制作用,金属蛋白酶抑制剂EDTA、丝氨酸蛋白酶抑制剂PMSF对Pep X有一定的抑制作用,说明Pep X为金属依赖性的丝氨酸肽酶。

关键词: X-脯氨酰-二肽酰基-氨基肽酶(Pep X), 纯化, 酶学性质

Abstract:

X-prolyl dipeptidyl aminopeptidase (Pep X) from Lactobacillus helveticus was purified and characterized. The
Pep X was released from Lactobacillus helveticus cells by sonication. The cell-free extract was purified by ammonium
sulfate precipitation, chromatographed on Sephacryl S-300 HR and native-PAGE gel. The molecular mass of purified Pep X
was measured by SDS-PAGE. The specific activity of the enzyme was 62.24 U/mg. The purified Pep X had monomer
molecular mass of approximately 26 kD. Optimal activity was observed at pH 7.0 and 37 ℃. It was activated by Co2+
and inhibited by Zn2+, Ni2+, Mn2+ and Fe3+. It was a metallopeptidase and serine proteinase that was inhibited by EDTA
and PMSF.

Key words: X-prolyl dipeptidyl aminopeptidase (Pep X), purification, enzyme characterization

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