关键词: 疟原虫感染红细胞, 细胞粘附因子1, 噬菌体随机肽库

Abstract: 　Objective To identify the binding site on ICAM 1 to PRBCs in order to explore anti adhesive agent against cerebral malaria. Methods Monoclonal antibody 15.2 against ICAM 1 domain 1 was chosen as target molecule to screen mimetic peptides of ICAM 1 from a 12 mer random peptide library. Three rounds of biopanning were carried out and then ELISA, competitive ELISA, dot ELISA and Western blotting were used to evaluate the binding character between phage borne peptides and McAb 15.2. The insert DNA sequences of positive clones were determined and their amino acid sequences were deduced. Results Thirty clones from the third round were randomly selected, and 26 of them were found positive by sandwich ELISA. The competitive ELISA test proved that most phage borne peptides could competitively inhibit the binding of antibody (15.2 McAb) with ICAM 1. Analysis of DNA and amino acid sequences indicated that over a half positive phage clones expressed 12 mer peptide KLYLIAEGSVAA. Comparison of peptide K(XX)L(XXX)GSV with the 64-73 aa of primary sequence of ICAM 1 showed a 50% homogeneity. Conclusion These peptides displayed by phage may be analogs of ICAM 1, K··L···GSV probably plays a significant role on the binding reaction of ICAM 1 and PRBCs.

Key words: Plasmodium infected red blood cells, intercellular adhesion molecule 1 (ICAM 1), phage displayed random peptide library