中文摘要：

[目的]以秦川牛为研究对象,克隆、原核表达秦川牛瘦素受体（Lepr）基因的蛋白功能区,分析表达蛋白对瘦素结合特性,为研究瘦素受体与瘦素结合的调节机制提供理论基础。[方法]本研究通过RT-PCR法从秦川牛肉mRNA扩增获得Lepr IG基因的cDNA序列,克隆至pMD18-T载体获得重组质粒,并进行序列测定。将测序正确的cDNA序列定向克隆到pET30a（NdeI/XhoI）,构建表达载体,并转化BL21（DE3）大肠杆菌,IPTG诱导后进行SDS-PAGE分析,镍柱亲和层析法分离纯化融合蛋白,高效液相色谱—迎头法分析重组表达蛋白对廋素结合功能。[结果]表明秦川牛Lepr IG基因在大肠杆菌中获得高效表达;Lepr IG融合蛋白以可溶性和包涵体2种形式表达;高效液相色谱—迎头分析法进一步表明重组表达蛋白具有结合瘦素的功能。[结论]秦川牛Lepr IG基因在大肠杆菌中获得高效表达,表达蛋白具有结合瘦素的功能,为通过调节瘦素受体对瘦素结合,抑制能量代谢,促进秦川牛脂肪沉积奠定了基础。

英文摘要：

【Objective】In this paper,the functional region of leptin receptor IG gene was cloned and expressed,the expressed protein combining leptin properties were analyzed,which would provide theoretical basis for the regulation of Lepr and leptin combinding.【Method】 The cDNA of Lepr IG gene was amplified from muscle mRNA of Qinchuan cattle by RT-PCR.The PCR product was cloned into the T vector pMD18-T to construct plasmid for sequencing.Then the cDNA was subcloned into the prokaryotic expressing plasmid vector pET30a（NdeI/Xho1） and transformed into host Escherichia coli strain BL2l（DE3） for expression.The expression of Lepr function protein was induced by IPTG,and was identified by SDS-PAGE.The protein was purified by Ni NTA column.Combinding leptin function of the expressed recombinant protein via high performance liquid chromatography frontal analysis（HPLC-FA）.【Result】The results showed that Lepr IG gene was highly expressed in Escherichia coli,and the expression product was observed with soluble protein and inclusion body,the expressed recombinant protein had the function of combinding leptin.【Conclusion】In vitro expressed exogenous,Lepr IG gene protein had combinding leptin function and the study provided the foundation for inhibitting Qinchuan cattle energy metabolism and fat deposition through regulation of Lepr on combinding leptin.