目的　构建编码人Ⅱ型胶原蛋白 2 5 0 2 70多肽片段(HuCⅡ 2 5 0 2 70 )的多聚基因 ,以获得高效表达、高度可溶和便于纯化的重组多肽基因。方法　选用大肠杆菌 (E .coli)偏爱密码子优化HuCⅡ 2 5 0 2 70的基因组成。通过化学合成和PCR法 ,获得HuCⅡ 2 5 0 2 70的基因 ,并利用BamHI和BglⅡ同裂酶进行酶切位点串联获得 6聚体。对影响重组HuCⅡ 2 5 0 2 70表达的各种因素进行系统研究 ,以获得优化表达的条件。对表达产物进行分离纯化。结果　酶切分析和DNA测序证实 ,6聚目的基因的构建正确。融合表达的量明显高于非融合表达 ,在优化条件下 ,可达 30 %。表达产物的可溶性明显提高 (在 90 %以上 ) ,其相对分子质量 (Mr)与预期的相符 ,纯化后的纯度达 90 %以上。结论　实现了HuCⅡ 2 5 0 2 70的高效表达 ,为研究类风湿性关节炎的发病机制和治疗提供了实验依据。为在原核细胞中高效表达的胶原蛋白的功能性小片段 ,提供了可供参考的借鉴 Objective To construct a polygenic gene encoding human collagen type 2 5 0 2 70 polypeptide (HuC Ⅱ 2 5 0 2 70) to obtain a recombinant polypeptide gene with high expression, high solubility and ease of purification. Methods The preferred codon usage of E.coli was used to optimize the gene composition of HuC Ⅱ 2 0 2 70. The gene of HuCⅡ25002 was obtained by chemical synthesis and PCR, and the 6-mer was obtained by tandem cleavage of BamHI and BglII. The factors influencing the expression of recombinant HuC Ⅱ 25072 were systematically studied to obtain the optimal expression conditions. The expression product was isolated and purified. Results Enzyme digestion analysis and DNA sequencing confirmed that the 6-mer gene was correctly constructed. The amount of fusion expression was significantly higher than the non-fusion expression, under the optimized conditions, up to 30%. The solubility of the expressed product was significantly improved (above 90%) and its relative molecular mass (Mr) was as expected, with a purity of over 90% after purification. Conclusion The high expression of HuC Ⅱ 2 0 2 70 was achieved and provided the experimental basis for studying the pathogenesis and treatment of rheumatoid arthritis. Provides a reference for the functional small fragments of collagen that is highly expressed in prokaryotes