1.Screening Peptide Mimetics Of Gal-a1, 3-Gal By Phage-display 2.Purification And Identification Of Conotoxin M ⅦA From A GTS Fusion Protein Expressed In Escherichia Coli

It is homotransplantations that are always used to treat organ's deterioration that is closer and closer to the cliff since the supplier is limited. In order to slove this intense problem, xenotransplantation becomes the new focus. And pig organ is the best choice of xenogeneic organ because of the similar size and genome.However, the pig xenogeneic antigen Gal-α1,3-Gal hampers the xenotransplantation, which can bind the human xenoreactive nuatural antibody, induce hyperacute rejection (HAR), act the cascade of compliements and result in the death of endodermis cells. From several viro or vitro experiments, the hyperacute rejection was proved to be avoided by interception the binding of the pig xenogeneic antigen to the human xenogeneic natural antibody. Accordingly, it becomes the key of xenotransplantation that how to keep the human xenogeneic natural antibody from the pig xenogeneic antigen Gal-α1,3-Gal.Lectin BS-I-B4 is used to mimic the human xenogeneic natural antibody since the capacity of binding Gal-α1,3-Gal. So it can be used to select Gal-α1,3-Gal mimikers. A peptide NCVSPYWCEPLAPSARA was got by biopanning to the lectin in the random phage-displayed library XCX 15, which was proved to have the capacity to bind the lectin BS-I-B4 and human serum A by competing with melibiose. Meanwhile the peptide was proved to have the function of inhibiting the coagulation the pig red blood cells with lectin BS-I-B4, polyclonal anti-human serum B antibody and human serumA. So it can be deduced that the peptide has the epitope similar with the pig xenogeneic antigen Gal-al,3-Gal, and can be used to delay the hyperacute rejction in the pig organ's xenotransplantation.