Physicochemical properties and biological activity of a recombinant inducible co-stimulator-Ig fusion protein / 第二军医大学学报

ABSTRACT

Objective: To investigate the physicochemical properties and biological activity of self-prepared fusion protein inducible co-stimulator-Ig. Methods: Acid hydrolysis, edman degradation and peptide mass finger printing were used to determine the amino acid composition, N-terminal 15 amino acid sequences, and peptide mapping. In vivo mixed lymphocyte reaction assay was used for identification of its biological activity. Results: The result of amino acids composition analysis was consistent with the theoretical value of ICOS-Ig. N-terminal 15 amino acid sequences of the product were EINGSANYEMFIFHN, consistent with the theoretical value of ICOS-Ig. Peptide match assay identified six peptides of the product which could match the theoretic maps of ICOS-Ig. ICOS-Ig and CsA noticeably inhibited the proliferation of allo-reactive T cells in vivo. Conclusion: The prepared ICOS-Ig fusion protein has a correct structure and can inhibit the proliferation of allogeneic T cells in vivo, which lays a foundation for quality control of ICOS-Ig fusion protein.