The object of this study is to investigate the properties of gastric cancer assoiciated antigen by McAb3H11 against gastric cancer cell line. Antigen purified by affinity chromatography and further charac- terized by ...The object of this study is to investigate the properties of gastric cancer assoiciated antigen by McAb3H11 against gastric cancer cell line. Antigen purified by affinity chromatography and further charac- terized by biochemical and immunological techiques. Results showed that assoiciated antigen of McAb 3H11 was mainly located on the membrane of target cells. It was sensitive to heat and digestion of proteases,but resistant to treatment with sodium periodate. Schiff’s reagent staining was negative. SDS-PAGE and IEF- analysis showed that the antigen was a 210 kD molecular weight with pl of 8. 5 protein. The molecular weight of antigen extracted from target cell with tunicamycin was not changed. We concluded that the cor- responding antigen of McAb 3H11 might be an alkaline protein.展开更多
A library of 2 ×107 random octapeptides was constructed by use of phagemid-based monovalent phage display system. The randomly synthesized degenerated oligodeoxyribonucleotides (oligos ) were fused to the truncat...A library of 2 ×107 random octapeptides was constructed by use of phagemid-based monovalent phage display system. The randomly synthesized degenerated oligodeoxyribonucleotides (oligos ) were fused to the truncated g Ⅲ (p230-p403). Sequence analysis of 11 randomly chosen clones suggested that the degenerated inserts and its deduced amino acid (aa) sequences are randomly distributed. The library was used to select binding peptides to the monoclonal antibody (mAb) 9E10, which recognizes a continuous decapeptide epi- tope of denatured human c-myc protein. After four to five rounds of panning, most of the eluted clones could bind to 9E10. Sequence analysis of the selected positive clones indicated that the binding sequences could fall into two classes, one class (clone 1) shares a consensus motif, ISE x x L, with c-myc decapeptide; and the sequences of the other class are entirely different. The binding of both classes to 9E10 could be specifically inhibited by free c-myc decapeptide. The immunogenicity of the phage peptide was further investigated by construction of multivalent displayed phage peptides and immunization of animals with or without adjuvant. ELISA and competitive ELISA showed that anti-serum from both mice and rabbit immunized with either clone could bind to the original antigen, c-myc decapeptide. These results denote that in spite of the dissimilarity of the selected peptides with c-myc decapeptide, they are capable of inducing similar immune respones in vivo, thus actually mimicking the antigen epitope.展开更多
文摘The object of this study is to investigate the properties of gastric cancer assoiciated antigen by McAb3H11 against gastric cancer cell line. Antigen purified by affinity chromatography and further charac- terized by biochemical and immunological techiques. Results showed that assoiciated antigen of McAb 3H11 was mainly located on the membrane of target cells. It was sensitive to heat and digestion of proteases,but resistant to treatment with sodium periodate. Schiff’s reagent staining was negative. SDS-PAGE and IEF- analysis showed that the antigen was a 210 kD molecular weight with pl of 8. 5 protein. The molecular weight of antigen extracted from target cell with tunicamycin was not changed. We concluded that the cor- responding antigen of McAb 3H11 might be an alkaline protein.
文摘A library of 2 ×107 random octapeptides was constructed by use of phagemid-based monovalent phage display system. The randomly synthesized degenerated oligodeoxyribonucleotides (oligos ) were fused to the truncated g Ⅲ (p230-p403). Sequence analysis of 11 randomly chosen clones suggested that the degenerated inserts and its deduced amino acid (aa) sequences are randomly distributed. The library was used to select binding peptides to the monoclonal antibody (mAb) 9E10, which recognizes a continuous decapeptide epi- tope of denatured human c-myc protein. After four to five rounds of panning, most of the eluted clones could bind to 9E10. Sequence analysis of the selected positive clones indicated that the binding sequences could fall into two classes, one class (clone 1) shares a consensus motif, ISE x x L, with c-myc decapeptide; and the sequences of the other class are entirely different. The binding of both classes to 9E10 could be specifically inhibited by free c-myc decapeptide. The immunogenicity of the phage peptide was further investigated by construction of multivalent displayed phage peptides and immunization of animals with or without adjuvant. ELISA and competitive ELISA showed that anti-serum from both mice and rabbit immunized with either clone could bind to the original antigen, c-myc decapeptide. These results denote that in spite of the dissimilarity of the selected peptides with c-myc decapeptide, they are capable of inducing similar immune respones in vivo, thus actually mimicking the antigen epitope.
