Secretion of human insulin by a transformed yeast cell.
A yeast expression plasmid encoding a mini-proinsulin molecule was constructed and transformed into Saccharomyces cerevisiae. The plasmid encoded the sequence: B-Arg-Arg-Leu-Gln-Lys-Arg-A in which B represents the B-chain (30 amino acid residues) and A represents the A-chain (21 amino acid residues) of human insulin. The secreted peptides were shown to be a mixture of human insulin and des(B-30)human insulin. Thus, correct disulphide bridges can be established in proinsulin-like molecules devoid of a normal C-peptide region. Furthermore, the specificity of the yeast processing enzymes is so similar to the proinsulin converting enzymes in the human pancreatic beta-cell that it allows the processing of the mini-proinsulin to insulin.
D000595:Amino Acid Sequence; D005796:Genes; D006801:Humans; D007328:Insulin / Q000096:biosynthesis / Q000235:genetics*; D010449:Peptide Mapping; D010957:Plasmids; D011994:Recombinant Proteins / Q000302:isolation & purification; D012441:Saccharomyces cerevisiae / Q000235:genetics*; D014170:Transformation, Genetic
D007328:Insulin; D011994:Recombinant Proteins