Abstract: The invention is related to a method for making mature human insulin or an analogue thereof by culturing a fungi cell comprising a DNA sequence encoding a precursor for human insulin or an analogue of human insulin which precursor comprises the B-chain of human insulin or an analogue thereof, the A-chain of human insulin or an analogue thereof and a C-peptide linking the B-chain and the A-chain together thereof, wherein the C-peptide comprises at least one Kex2 cleavage site and an amino acid sequence attached at one end to the C-terminal amino acid residue in the B-chain and at the other end to the Kex2 site which amino acid sequence will facilitate a more efficient Kex2 cleavage within the fungi cell. The C-terminal extension of the B-chain may furthermore be capable of subsequently being cleaved off from the C-terminal amino acid residue in the B-chain by means of a carboxypeptidase activity either within the fungi cell or subsequently in the culture medium.

Abstract: The present invention relates to novel insulin analogues exhibiting resistance towards protease, wherein at least two amino acids are substituted and/or deleted relative to the parent insulin molecule. A method for the preparation of such insulin analogues, insulin preparations containing the insulin analogues of the invention and a method of treating diabetes mellitus using these insulin analogues is also provided.