生物技术通报 ›› 2018, Vol. 34 ›› Issue (3): 200-207.doi: 10.13560/j.cnki.biotech.bull.1985.2017-0795

• 研究报告 • 上一篇    下一篇

植酸酶YiAPPA与生淀粉结合域SBD融合酶的构建及酶学性质分析

袁林, 黄朝, 曾静, 郭建军, 张婷, 吕珺,   

  1. 江西省科学院微生物研究所,南昌 330096
  • 收稿日期:2017-09-21 出版日期:2018-03-20 发布日期:2018-04-10
  • 作者简介:袁林,男,副研究员,博士,研究方向工业微生物应用;E-mailyuanlinjxas@126.com
  • 基金资助:
    国家自然科学基金青年科学(31501422),江西省青年科学(20171BAB214003),江西省重点研发计划项目(20171BBF60006),江西省科学院资助项目(2017-YCXY-13,2018-JCQN-02,2018-YCXY-02)

Fusion of Phytase YiAPPA with the Raw-starch Binding Domain and Characterization of the Fusion Enzyme

YUAN Lin, HUANG Zhao, ZENG Jing, GUO Jian-jun, ZHANG Ting, Lü Jun   

  1. Institute of Microbiology,Jiangxi Academy of Sciences,Nanchang 330096
  • Received:2017-09-21 Published:2018-03-20 Online:2018-04-10

摘要: 旨在获得酶学性质改良的植酸酶YiAPPA与生淀粉结合域SBD的融合酶。通过在植酸酶YiAPPA的C末端融合嗜热酸性α-淀粉酶GTamy的生淀粉结合域SBD,获得融合酶YiAPPA-SBD。酶学性质分析表明,YiAPPA-SBD的高温活性和热稳定性得到了提高,并获得了对生玉米淀粉的结合能力。其中YiAPPA-SBD于55-90℃范围内的相对酶活均高于YiAPPA的相对酶活;于80℃的半衰期提高约2倍;在生玉米淀粉浓度大于8%的条件下,YiAPPA-SBD对其结合率达到80%以上。并且YiAPPA-SBD保留有YiAPPA的其它优良酶学性质,最适反应pH为4.5,37℃的绝对酶活高达3 900 U/mg,具有优良的pH稳定性和蛋白酶抗性。

关键词: 植酸酶YiAPPA, 生淀粉结合域, 融合酶, 热稳定性, 生淀粉结合率

Abstract: This work aims to obtain a fusion enzyme with improved enzymatic properties comprised of phytase YiAPPA and raw-starch binding domain SBD. The raw-starch binding domain(SBD)of thermoacidophilic α-amylase GTamy was introduced into the C-terminal end of Yersinia intermedia phytase(YiAPPA)to generate a fusion enzyme YiAPPA-SBD. The fusion of YiAPPA with SBD resulted in improvements both in terms of thermal activity and stability. Besides,YiAPPA-SBD could absorb raw corn starch. Specifically,YiAPPA-SBD exhibited higher relative activity than YiAPPA within 55-90℃.The half-life of YiAPPA-SBD increased from 15 min to 30 min when incubated at 80℃. The adsorption efficiency of YiAPPA-SBD was 80% when the raw corn starch concentration was over 8%. Moreover,YiAPPA-SBD showed minor changes in its specific activity(3 900 U/mg)at optimal pH(pH 4.5),indicating that YiAPPA-SBD has solid pH stability and resistance to protease when compared to YiAPPA.

Key words: phytase YiAPPA, raw-starch binding domain, fusion enzyme, thermostability, raw-starch adsorption efficiency