高等学校化学学报 ›› 1995, Vol. 16 ›› Issue (2): 211.

• 论文 • 上一篇    下一篇

聚半乳糖醛酸酶(PG2)中色氨酸残基的化学修饰

王红梅, 刘嘉莉, 杨萍, 刘兰英   

  1. 吉林大学分子生物学系, 长春 130023
  • 收稿日期:1994-02-25 修回日期:1994-11-12 出版日期:1995-02-24 发布日期:1995-02-24
  • 通讯作者: 刘兰英
  • 作者简介:王红梅,女,26岁,现在北京大学工作.

The Chemical Modification of Tryptophan Residues in Polygalacturonase

WANG Hong-Mei, LIU Jia-Li, YANG Ping, LIU Lan-Ying   

  1. Department of Molecular Biology, Jilin University, Changchun, 130023
  • Received:1994-02-25 Revised:1994-11-12 Online:1995-02-24 Published:1995-02-24

摘要: 用化学修饰法以N-溴代琥珀酰亚胺作修饰剂,对聚半乳糖醛酸酶(PG2)中色氨酸(Trp)残基与酶活性的关系进行研究,发现1个PG2分子中有6个Trp残基,其中4个位于酶分子内部,2个位于酶分子表面.该发现通过表面荧光猝灭实验得到进一步证明.酶分子表面的2个Trp残基中,有1个为活性必需的氨基酸,它的修饰导致大部分酶活力丧失.底物保护实验进一步证明该活性必需的Trp可能位于酶的活性部位.酶被修饰后其圆二色谱及荧光光谱发生了变化.

关键词: 聚半乳糖醛酸酶, 色氨酸, 化学修饰

Abstract: The tryptophan residues in polygalacturonase(PG2) had been modified by N-bromosuccinimide(NBS) to study the relationship between the Trp residues and the activity of the enzyme.The results indicate that there are six Trp residues in PG2.Four of them locate in the interior and the other two locate on the surface of the enzyme molecule.One of the Trp residues,which is on the surface of PG2,is essential for the activity of the enzyme and locates at the active site of the enzyme.The spectra of circular dichroism(CD) and fluorescence of PG2 are changed after treatment with NBS.

Key words: Polygalacturonase, Tryptophan, Chemical modification.

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