Characterization of two halophilic adenylate cyclases from Thermobifida halotolerans and Haloactinopolyspora alba  

作　　者：Dahai Jiang Zhidi Min Jing Leng Huanqing Niu Yong Chen Dong Liu Chenjie Zhu Ming Li Wei Zhuang Hanjie Ying 

机构地区：[1]State Key Laboratory of Materials-Oriented Chemical Engineering,College of Biotechnology and Pharmaceutical Engineering,Nanjing Tech University,Nanjing 211816,China

出　　处：《Chinese Journal of Chemical Engineering》2023年第1期56-62,共7页中国化学工程学报（英文版）

基　　金：supported by Jiangsu Province Natural Science Foundation for Distinguished Young Scholars(BK20190035);Jiangsu Government Scholarship for Overseas Studies(JS-2019-053);Key Research&Development plan of Jiangsu Province(BE2019001);the National Natural Science Foundation of China(2217080044 and 22008119);the Natural Science Foundation of Jiangsu Province(BK20202002);the National Key Research and Development Program of China(2021YFC2101204);the Program for Changjiang Scholars and Innovative Research Team in University(IRT_14R28);the Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD);the Jiangsu Synergetic Innovation Center for Advanced Bio-Manufacture.

摘　　要：Adenylate cyclase(AC)is the key enzyme that catalyzes the formation of cAMP from ATP.In this study,we discovered two novel class Ⅲ ACs with a halophilic property from Thermobifida halotolerans DSM 44931(ThAC)and Haloactinopolyspora alba DSM 45211(HaAC),respectively.The recombinant ThAC and HaAC were expressed in Escherichia coli with molecular weights of 36.1 and 36.0 kDa respectively.The presence of 2500 and 2200 mmol
L^(-1)1 NaCl significantly enhanced the enzyme activities of ThAC and HaAC,with 22-fold and 7.4-fold higher activities compared to those without NaCl,respectively.Several divalent metal ions were found to activate the recombinant ACs to different extents,and the optimal metal ion was Mg^(2+)for both ThAC and HaAC with concentrations of 80 mmol·L^(-1) and 40 mmol·L^(-1) respectively.Purified ThAC and HaAC had the optimal specific activities((4.59±0.35)×10^(4) and(7.76±0.52)×10^(4) U·mg^(-1))and catalytic efficiency(4.47 and 5.30 L·mmol^(-1)·s^(-1))at 45
℃ and 40
℃ respectively,while the optimum pH of both two recombinant ACs was 10.0.This is the first report of the halophilic Class III ACs,which could make new contributions to explore and study ACs for further associated investigations.

关 键 词：ENZYME Protein stability BIOTECHNOLOGY Halophilic adenylate cyclase CAMP 

分 类 号：TQ426.97[化学工程] Q936[生物学—微生物学]