Utilization of MelC1 signal peptide of Streptomyces spp. for secretory production of human epidermal growth factor

• Main Authors: HSIAO, CHING-YI, 蕭清懿
• Other Authors: SHIAU, CHIA-YANG
• Format: Others
• Language: zh-TW
• Published: 2008
• Online Access: http://ndltd.ncl.edu.tw/handle/92604046462676141595

碩士 === 國防醫學院 === 微生物及免疫學研究所 === 96 === Human epidermal growth factor (hEGF) has important biological functions and widely been used in clinical and cosmetic fields. Thus, production of hEGF in safe quality and in high quantity is desired. In this studies, MelC1 signal peptide of Streptomyces was fused with the gene of hEGF for secretory production in E. coli or in Streptomyces lividans 66. Under control of T7 promoter, pHL701/mel-hEGF was successfully expressed in cytosol of E. coli and the desired hEGF was secreted into medium as detected by western blotting and MALDI-TOF. It was found that mel-hEGF or hEGF encoded in pJNC101 or pJNC102 under control of snpA promoter was expressed in cytosol of S. lividan in low level and no evidence of extracellular secretion has been obtained based on western blotting. Failure of detecting secretory product could derive from low level of expression in cytosol. Recently discovered TAT pathway in E. coli could be the route for the secretory production of hEGF since Mel signal peptide of streptomyces belong to TAT family and Caf1 whoch belongs to SEC family was not able to bring about the secretory production of hEGF under similar circumstance. Also, it could be that strong T7 promoter drove a lot of expression of hEGF for MelC1 mediated secretion into medium.