【摘要】 目的构建人胱抑素C(cystatin C,Cys C)的原核表达载体,并用纯化的Cys C重组蛋白免疫家兔,制备CysC抗血清。方法从HL-60细胞中提取总RNA,RT-PCR扩增Cys C基因,将测序正确的目的基因克隆至pET32(a)表达载体中,并诱导其在大肠杆菌BL21(DE3)中表达;所获得的包涵体蛋白经亲和层析纯化、透析复性、Western blot鉴定后,免疫家兔制备抗血清,抗体效价和特异性分别采用ELISA、Western blot进行检测。结果测序证实克隆的基因序列与GeneBank中的Cys C序列相符;SDS-PAGE、Western blot结果证实获得相对分子质量为35×103的Cys C融合蛋白,其表达形式为不溶性包涵体;此包涵体蛋白经Ni2+亲和层析能有效纯化,以该蛋白免疫家兔制备抗血清,抗体效价为1∶8000,Western blot检测证实该抗体能与目的蛋白发生特异性结合。结论获得了Cys C重组蛋白及特异性多克隆抗体。更多还原

【Abstract】 Objective To construct a prokaryotic expression vector of cystatin C (Cys C), purify Cys C protein produced by the expression system, and prepare its antiserum. Methods Total RNA was isolated from HL-60 cells, and human Cys C gene was amplified with RT-PCR. The cDNA fragment was cloned into pMD18-T vector and which was confirmed by sequencing. The enzyme-digested target fragment was cloned into PET-32(a) expression vector and transfected into E.coli. BL 21(DE3), in which Cys C expression was induced. After the inclusion body protein was purified through Ni2+ affinity chromatography, processed by dialysis, identified by Western blotting, a rabbit was immunized with the fusion protein, and the antiserum was obtained. Results The result of DNA sequence analysis showed that the cloned Cys C gene sequence was completely corresponding to GenBank data. SDS-PAGE and Western blotting showed that the expressed Cys C fusion protein was about 35×103, mainly existing in the inclusion body of E.coli., that could be purified through Ni2+ affinity chromatography. The titer of the antiserum to the purified protein was 1∶8 000 by ELISA, and Western blotting confirmed that the antiserum reacted specifically to the Cys C protein. Conclusion A recombinant Cys C protein and the specific polyclonal antibody have been obtained, which provides a basis for establishment of immunoassays of human Cys C.更多还原