通过融合双亲短肽改善L-天冬酰胺酶酶学特性

Improvement of Characteristic of L-Asparaginase through Fusing Six Self-Assembling Amphipathic Peptides to Its N-Terminal

DOI：10.3969/j.issn.1673-1689.2015.11.010

中文关键词: L-天冬酰胺酶 双亲短肽 融合 酶学特征

英文关键词: L-asparaginase,self-assembling amphipathic peptides,fusion,characterization

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中文摘要:

L-天冬酰胺酶可以将L-天冬酰胺水解成L-天冬氨酸与氨，主要应用在医药与食品行业。作者尝试在L-天冬酰胺酶N-末端融合不同的自组双亲短肽，改善该酶的酶学特性。首先，利用分子克隆技术将6条分别具有不同特征的短肽与L-天冬酰胺酶的N-端融合，并在Escherichia coli BL21中进行表达，最后，利用Ni2+-NTA纯化获得纯的重组L-天冬酰胺酶酶液。结果表明，融合SAP4对L-天冬酰氨酶（ansZ酶）动力学特征影响较大，融合蛋白SAP4-ansZ的比活力较融合前提高约30%，其中重组蛋白Km值较原始酶下降了7.5%，而Vmax值得提升了10%，说明融合SAP4可以改善ansZ酶对L-天冬酰胺的水解效率。

英文摘要:

L-asparaginase（Asn） can catalyzes the hydrolysis of L-asparagine to L-aspartic acid and ammonia. It is mainly applied in pharmaceutical and food industry. In this study，to improve the characteristic of Asn，we fused six self-assembling amphipathic peptides（SAPs） to its N-terminal and expressed the recombinant Asns in E. coli，respectively. Compared to wide-type Asn，the SAP4-Asn activity increased by 30%，the value of Km decreased by 7.5% and the Vmax increased by 10%. The reaction kinetics analysis showed that the affinity ability and catalytic efficiency of the fusion enzyme towards L-asparagine improved compared to wide-type Asn.

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