目的　克隆血小板衍生的生长因子A链 (PDGF A)的基因 ,并在大肠杆菌中表达。方法　利用RT PCR法 ,从人肝癌细胞系 (HHCC)的总RNA中 ,扩增PDGF A的全长cD NA ,再用PCR法扩增PDGF A成熟蛋白的全长编码序列。编码序列经测序验证后 ,克隆入表达载体pGEX 4T 1中 ,构建PDGF A的原核表达载体 ,在大肠杆菌中诱导表达目的蛋白 ,并进行谷胱甘肽 (GST)亲和层析纯化。结果　以RT PCR扩增的PDGF A基因的全长为 12 5 5bp ,以PCR扩增得到其成熟蛋白的编码序列为 5 31bp。构建了PDGF A基因的原核高效表达载体pGEX PDGF A ,表达产物主要位于包涵体内。对包涵体蛋白进行变性和复性处理后 ,利用亲和层析法获得纯化的目的蛋白。结论　成功地扩增到PDGF A成熟蛋白的编码序列 ,并在大肠杆菌高效表达 ,为进一步对PDGF A功能的研究提供了有利的工具 Objective To clone the gene of platelet - derived growth factor A chain (PDGF A) and express in E. coli. Methods The full length cD NA of PDGF A was amplified by RT PCR from the total RNA of human hepatocellular carcinoma cell line (HHCC). The full length coding sequence of PDGF A mature protein was amplified by PCR. The coding sequence was verified by sequencing and cloned into the expression vector pGEX 4T 1 to construct the prokaryotic expression vector of PDGF A. The expressed protein was induced in E. coli and purified by glutathione (GST) affinity chromatography. Results The full length of PDGF A gene amplified by RT PCR was 125 bp. The coding sequence of its mature protein was 5 31 bp by PCR. The prokaryotic expression vector pGEX PDGF A of PDGF A gene was constructed, and the expression product was mainly located in the inclusion body. The inclusion body protein denaturation and renaturation treatment, the use of affinity chromatography to obtain the purified protein of interest. Conclusion The coding sequence of PDGF A mature protein was successfully amplified and expressed in Escherichia coli, which provided a favorable tool for the further study of PDGF A function