利用大肠杆菌鞭毛展示的随机肽库筛选TNF-α拮抗肽

Screening of TNF-α Antagonist Peptides from a Random Peptide Library Displayed with Escherichia coli Flagellar

TNF α是一种在机体抗感染、抗肿瘤过程中发挥重要作用的细胞因子 ,其对机体具有保护和损伤两方面的作用 ,为了探讨新的抑制TNF α所致炎症损伤等反应的手段 ,构建了细菌鞭毛递呈的随机肽库 ,利用构建得到的肽库 ,进行TNF α特异性结合肽的筛选工作。经过 5轮筛选及DNA测序 ,共得到 6条小肽编码序列。其中 2条序列中含有一V N WG的相同序列框架。进行 6条序列与TNF α结合力的确证后 ,选择了其中的 4条肽序列进行人工化学合成、纯化及鉴定。利用L92 9细胞及MTT法对 4条小肽进行活性测定 ,检测其对TNF α的抑制活性。结果表明 ,在TNF α对L92 9细胞毒性为 30 %左右时 ,含同源序列框架的 2条肽可抑制 90 %左右的TNF

Tumor necrosis factor(TNF-α) plays an improtant role in the process of anti-infection and anti-cancer.It can both protect and make damage to the host.In order to find new way of inhibiting its host-damaging activity, An E.coli flagella displayed random peptide library was constructed and TNF-αantagonist peptides were screened using the peptide library. After 5 rounds of panning and DNA sequencing, six peptide sequences were obtained.Two of them(TBP2,TBP3) have the same sequence frame of V--N-WG.After primary comparation of TNF-α binding ability,four peptides were synthesised and purified with RP-HPLC.The activity of inhibiting TNF-α was detected with L929 cell and MTT method.The data show that TBP2 and TBP3 can inhibit 90% of TNF-α activity when TNF-αgives about 30% cell toxicity on L929.The two sequences have not been reported.