Biopanning of HCV antigen epitopes from a random 12-peptide library by anti-hepatitis C virus polyclonal antibody / 中南大学学报(医学版)

Objective To analyze the epitopes of anti-hepatitis C virus(HCV)antibodies by peptide library biopanning. Methods Phage random peptide library of 12 amino acids was immunoscreened with purified IgG from the sera of hepatitis C patients. Positive clones which were obtained after 3 rounds of biopanning were detected by ELISA and 4 of them were sequenced. Results After 3 rounds of screening, the radio of output to input increased from (4.6×10~(-4))% to (5.3×10~(-2))%, meaning the enrichment was effective. At the third round of screening, all the selected clones proved to specifically react with the sera for immunoscreening. Four positive phage clones were sequenced, which shared a very conservative sequence and was named as C1. Its inserting sequence in the coat protein III was deduced to be GSMSPYVRWYTP, and the positive rate of C1 reacted with 20 cases of HCV patients was 85%.Conclusion The antigen-mimic peptide C1 is successfully screened from 12 random phage peptide library and it has some diagnostic value.

Screening of conjugated peptides of Endoglin from phage display peptide library / 第三军医大学学报

Objective To screen rhEndoglin-binding peptides from phage displayed 12-peptide library. Methods The rhEndoglin was used as target protein for biopanning of phage-displayed 12-peptide library. After three rounds of screening, 16 phage clones were randomly selected and identified by sandwich ELISA. The positive phage clones were sequenced, and the fuse peptides were deduced by the DNA sequence. Further we identified the affinity and speciality by competitive inhibition test. Results Six of 16 phage clones were identified as positive clones by competent ELISA which could bind to rhEndoglin. Five sequences were obtained, and the amino acid sequence in two of these five was AHKHVHHVPVRL. Conclusion The rhEndoglin-binding peptides can be obtained by screening phage random peptide library. It could play an important role in early diagnosis of ovarian cancer.

Screening and function analysis of targeted short binding peptides of Endoglin / 重庆医科大学学报

Objective:To do screening in phage displayed 12-peptide library to seek short peptides capable of binding Endoglin detect their affinity constants.Methods:After three rounds of screening,16 phage clones were randomly selected and their affinity was identified by sandwich ELISA.The DNA sequence of positive phage clones was determined,and their speciality was identified by competitive inhibition test.We finally calculated out the affinity constants of those positive phage binding peptides by non-competitive ELISA method.Result:After three rounds of screening,the enriched phage clones were identified. 6 of 16 phage clones were identified positive by competitive ELISA,which had comparatively strong binding activity to rhEndoglin.Five sequences were obtained,and the predominant sequence was AHKHVHHVPVRL.Competitive inhibition test showed that positive phage clones had good affinity to Endoglin,with the affinity constant as(1.431?0.293)?107 mol/L.Conclusion:The rhEndoglin-binding peptides with high affinity to Endoglin can be obtained through the screening of phage random peptide library, which is beneficial to the further studies on the function of Endoglin in the early diagnosis of ovarian cancer.