[Screening of TNF-alpha antagonist peptides from a random peptide library displayed with Escherichia coli flagellar]

Tumor necrosis factor(TNF-alpha) 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-alpha antagonist 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-alpha binding ability, four peptides were synthesised and purified with RP-HPLC. The activity of inhibiting TNF-alpha was detected with L929 cell and MTT method. The data show that TBP2 and TBP3 can inhibit 90% of TNF-alpha activity when TNF-alpha gives about 30% cell toxicity on L929. The two sequences have not been reported.