重组人角质细胞生长因子-2基因的克隆和表达

目的：克隆人KGF-2基因，并在大肠杆菌中进行表达。方法：通过PCR扩增，从人胎肝cDNA文库中获得编码人KGF-2的cDNA，并将其分别克隆入pBV220，pLEX和pGEX4T-1质粒中，研究其在不同表达质粒和大肠杆菌中的表达情况。结果：克隆得到的KGF-2cDNA经测序证明与文献报道的序列一致。将其克隆于pBV220质粒中，在E．coli JM109中表达量相对最高，约占茵体总蛋白的4％；克隆于pLEX质粒中，在E．coli G1724中的表达量约占全茵总蛋白的5％；克隆于pGEX4T-1中，在E．coli JM109中的表达量可占到全茵总蛋白的20％。结论：采用GST融合蛋白表达质粒pGEX4T-1对KGF-2进行表达，较pBV220和pLEX具有明显优势，能实现对KGF-2的高效表达，为进一步的功能研究奠定了基础。

Cloning and expression of recombinant human KGF-2 in E.coli

Objective:To clone the gene of human keratinocyte growth factor-2 (KGF-2) and express it in E.coli. Methods: KGF-2 cDNA was obtained from human fetal liver cDNA library by PCR and cloned into several plasmids respectively to investigate its expression in different E.coli strains. Results: Sequencing analysis showed that the obtained KGF-2 cDNA was consistent with that reported. When cloned into pBV220,the highest expression of KGF-2 was achieved in E.coli JM109, accounting for about 4% of the total cell protein. Cloned into pLEX and pGEX4T-1 respectively, the KGF-2 amounted to about 5% of total cell protein in former and 20% in latter. Conclusion: The results suggest that the gene of KGF-2 reaches a high level of expression by cloning into pGEX4T-1. It provides a reliable foundation for the functional investigation of KGF-2.