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。
This work aims to obtain a fusion enzyme with improved enzymatic properties comprised of phytase YiAPPA and raw-starchbinding domain SBD. The raw-starch binding domain（SBD）of thermoacidophilic α-amylase GTamy was introduced into the C-terminal end ofYersinia intermedia phytase（YiAPPA）to generate a fusion enzyme YiAPPA-SBD. The fusion of YiAPPA with SBD resulted in improvementsboth in terms of thermal activity and stability. Besides,YiAPPA-SBD could absorb raw corn starch. Specifically,YiAPPA-SBD exhibitedhigher 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 showedminor changes in its specific activity（3 900 U/mg）at optimal pH（pH 4.5）,indicating that YiAPPA-SBD has solid pH stability andresistance to protease when compared to YiAPPA.
作者
袁林
黄朝
曾静
郭建军
张婷
吕珺
YUAN Lin;HUANG Zhao;ZENG Jing;GUO Jian-jun;ZHANG Ting;LU Jun(Institute of Microbiology, Jiangxi Academy of Sciences, Nanchang 33009)
出处
《生物技术通报》
CAS
CSCD
北大核心
2018年第3期200-207,共8页
Biotechnology Bulletin
基金
国家自然科学基金青年科学基金项目(31501422)
江西省青年科学基金项目(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)
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
phytase YiAPPA
raw-starch binding domain
fusion enzyme
thermostability
raw-starch adsorption efficiency
