Objective:To construct expression vector of insulin glargine ( ING) and increase soluble expression of ING.Methods: C peptide was used to join A chain and B chain of ING in previous studies .In the present research , thioredoxin ( Trx) was inserted between A chain and B chain of ING to replace C peptide .Co-expression of molecular chaperones GroEL , GroES, trigger factor and ING was also used to promote folding of recombinant ING-Trx protein.Results:Soluble ING-Trx accounts for 35% of total expressed ING-Trx while soluble ING-Trx increased to 78%of total ING-Trx protein after co-expression.The yield was about 4.5 mg· L-1 after preliminary purification , three times as much as the production without co-expression of molecular chaperones .Conclusion:In summary , A chain and B chain can fold properly when Trx is used to replace C peptide .Co-expression of ING-Trx with molecular chaperones can greatly increase soluble expression of insulin glargine .%目的：构建甘精胰岛素（ ING）表达载体，提高ING在大肠杆菌中的可溶性表达。方法：在传统方法中ING的A、B链之间用C肽连接，本实验在ING的A、B链之间插入大肠杆菌硫氧还蛋白质（ Trx ）来替代C肽，进行ING的融合表达（ ING-Trx），并进一步使用多分子伴侣GroEL、GroES、触发因子进行共表达。结果：可溶性的ING-Trx融合蛋白约占该目的蛋白质总表达量的35％；多分子伴侣共表达后可溶性ING-Trx的产量提高到ING-Trx总蛋白的78％，初步纯化后其产量为4.5 mg· L-1，是使用分子伴侣前的3倍。结论：用Trx代替C肽不影响A、B链的有效折叠，采用分子伴侣共表达可以显著提高目的蛋白的可溶性。
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