摘要
该研究从毛白杨中克隆到1个Phi类谷胱苷肽S-转移酶（GST）基因（PtoGSTF4），编码213个氨基酸。表达模式分析发现，PtoGSTF4在正常生长、Hzoz和莠去津处理后的茎、叶以及茎的韧皮部均表达，属于组成型表达基因。在大肠杆菌中表达并纯化了PtoGSTF4重组蛋白，酶学性质分析表明PtoGSTF4对CDNB、NBD-C1、NBC和Cum—OOH等4种底物均有活性。动力学分析发现，PtoGSTF4对GSH具有较高的亲和力，而对CDNB的亲和力相对较低。在不同pH及温度条件下对PtoGSTF4蛋白进行活性检测，发现PtoGSTF4在pH7．5～10．5范围内或30℃～60℃温度范围内有较高的活性。研究推测，PtoGSTF4可能在毛白杨的抗逆生理中发挥重要作用。
In this study,a Phi class GST named PtoGSTF4 was cloned from Populus tomentosa. PtoGSTF4 encodes a protein of 213 amino acid residues. RT-PCR revealed that PtoGSTF4 was a constitutively expressed gene that is expressed in stem, leaf and phloem of stem of P. tomentosa under normal growth condition,and H202 and atrazine stressed conditions. The recombinant PtoGSTF4 was expressed in E. coli and purified by Ni^2＋ sepharose affinity chromatography. PtoGSTF4 showed enzymatic activities towards substrates CI）NB,NBI）-Cl,NBC and Cum-OOH. Kinetic analysis found that the affinity of PtoGSTF4 to GSH was higher than that to CDNB. PtoGSTF4 had optimal pH ranging from 7.5-10.5 and optimal temperature ranging from 30 ℃-60℃. Our results indicated that PtoGSTF4 may play important roles in stress tolerance in P. tomentosa.
出处
《西北植物学报》
CAS
CSCD
北大核心
2013年第12期2369-2374,共6页
Acta Botanica Boreali-Occidentalia Sinica
基金
国家自然科学基金(31270641)
关键词
谷胱苷肽S-转移酶
毛白杨
表达模式
酶学性质分析
glutathione S-transferase
Populus tomentosa
expression pattern
enzymatic characterization
