Abstract: 　　　Abstract Objective: To construct several human proinsulin mutants related to diabetes and express in INS-1 cell. Methods: Human mild proinsulin gene as template ,use site-directed mutagenesis，generate four human proinsulin mutants by PCR，sequence each mutant，transfect four mutants、empty plasmid and mild plasmid into INS-1 cell by liposome 2000，determine insulin values in each cell solution by radioimmunoassay. Results: Proinsulin mutants are confirmed by sequence determination ,insulin values in culture solution of H-C(B19)G、 H-L(B11)P、H-R(S6)C mutants are less than that of wild type and found no significant differences statistically with empty plasmid. insulin values of H-F(B25)L is more than that of empty plasmid and the former three mutants. Conclusions: Successfully construct and express four human proinsulin mutants, different mutants result in diabetes through different mechanism.

Key words: 　Endoplastic reticulum stress, Proinsulin misfolding, mutagenesis, site-directed, plasmids, permanent neonatal diabetes mellitus, transfection, B细胞功能衰竭