rhSCF在大肠埃希菌中的高效表达及纯化

干细胞因子（SCF）是一种重要的造血生长因子，它在自体造血干细胞动员、肿瘤放疗化疗的辅助治疗以及其它血液病的治疗上具有良好的应用前景。为了制备高纯度、活性的重组人SCF，将人工合成的SCF的cDNA序列，克隆入原核表达载体pET43．1a中，转化大肠埃希菌BL21（DE3），获得了高效表达菌株。SCF通过诱导表达形成包涵体，包涵体经洗涤、变性和初步纯化后，进行直接稀释复性，复性液经离子交换层析、分子筛层析等分离除去共价二聚体和异构体，获得纯度大于95％的重组人SCF样品，生物学比活性在7．0×10^5U／mg以上。结果表明：建立了有效的rhSCF制备工艺，且产物具有较高的纯度和生物学活性。

High-Level Expression of Recombinant Human Stem Cell Factor (rhSCF) in E. coli and Its Purification

Stem cell factor (SCF) is an important hematopoietie growth factor, it has good prospects in the applica-tions of autogenous hematopoiesis of stem cell mobilization, in auxiliary therapy of radiotherapy and chemotherapy of tumor, and in therapy of blood diseases. In order to prepare highly pure and active rhSCF, eDNA sequence of artifi-cially synthesized SCF was cloned into prokaryotie expression vector pET43, la to transform E. Coli BL21 (DE3) and obtained a highly effective expression strain. An inclusion body express-formed through inducing SCF and after washed, denatured, and initially purified was renatured directly through dilution. Covalent dimer and isomer in the re-natured liquid was isolated and removed through ion exchange chromatography, molecular sieve chromatography and other means. And obtained rhSCF sample of purity above 95% with bio-specifie activity at over 7.0 × 10~5 U/mg. Theresults showed that the effective preparation technology of rhSCF had been established, and the product had fairly high purity and biological activity.