小热激蛋白(sHSPs)是植物在逆境条件下产生的一类具有分子伴侣活性的应激蛋白,本研究拟构建原核表达载体并表达具生物学活性的麻疯树小热激蛋白以进一步研究其功能及应用.从麻疯树胚乳cDNA文库中获得全长为652 bp的cDNA序列,包含一个426 bp的开放阅读框,编码分子量大小约为15 926.13的胞质Ⅰ型小热激蛋白,命名为JcHSP15.9.通过构建原核表达载体,得到BL21(DE3)plysS/pET32a-HSP重组菌株.用JcHSP15.9在大肠杆菌中的过量表达来研究它的耐热胁迫能力,发现在常温(37℃)下重组菌株与野生型菌株生长曲线基本相似,但在高温(50℃)下重组菌较对照组菌株存活率有了显著的提高,推测JcHSP15.9可能与麻疯树的耐热胁迫有关.通过镍亲和层析柱纯化得到纯度较高的JcHSP15.9蛋白,分子量大小与预期一致,蛋白条带单一清晰.
The ubiquitous small heat shock proteins are synthesized by all plants in response to elevated temperatures and other stresses. Jatropha curcas cytoplasmic class I small heat shock protein (JcHSP15.9) cDNA with full length of 652 bp was cloned from the endosperm cDNA library ofJ. cureas L. To verify its possible function, recombinant JeHSP15.9 was overexpressed in Escherichia coll. The results showed that the growth transformed cells was similar to that of wild type at 37 ℃, but the recombinant gene significantly improved cell viability in thermal stress condition (50 ℃) compared with the control. JeHSP15.9 protein was purified with His-Trap-Kit. Fig 5, Ref22