Single-chain insulin analogues stabilized by a fourth disulfide bridge
A single-chain insulin analogue comprises a B-chain insulin polypeptide connected to an A-chain insulin polypeptide by a C-domain polypeptide. The B-chain insulin polypeptide contains a Cysteine substitution at position B4. The A-chain insulin polypeptide contains a Cysteine substitution at position A10. The C-domain polypeptide is 4 to 11 amino acids long. The analogue mitigates the unfavorable activity of this 4th disulfide bridge in conventional two-chain insulin analogues resulting in a duration of insulin signaling similar to that of wild-type insulin. A method of treating a patient with diabetes mellitus comprises the administration of a physiologically effective amount of the protein or a physiologically acceptable salt thereof to a patient. Use of a single-chain insulin analogue of the present invention in an insulin delivery device (such as a pump or pen) or as part of a high-temperature polymer-melt manufacturing process.
1. A single-chain insulin analogue comprising a B-chain insulin polypeptide sequence connected to an A-chain insulin polypeptide sequence by a C-domain polypeptide sequence; wherein the B-chain insulin polypeptide sequence contains a Cysteine substitution at position B4 relative to the sequence of wild type insulin; wherein the A-chain insulin polypeptide sequence contains a Cysteine substitution at position A10 relative to the sequence of wild type insulin and wherein the C-domain polypeptide sequence is 4 to 11 amino acids long.
2. The single-chain insulin analogue of claim 1 , wherein the C-domain polypeptide sequence comprises an N-terminal acidic element and a C-terminal basic element.
3. The single-chain insulin analogue of claim 1 , wherein the analogue comprises any one of SEQ ID NOS: 4-31.
4. The single-chain insulin analogue of claim 3 , wherein the C-domain polypeptide begins with Glu-Glu.
5. The single-chain insulin of claim 4 , wherein the C-domain polypeptide comprises residues 31-36 of SEQ ID NO: 31.
6. The single-chain insulin of claim 5 , wherein the analogue comprises SEQ ID NO: 31.
7. The single-chain insulin of claim 4 , wherein the C-domain polypeptide comprises residues 31-38 of SEQ ID NO: 30.
8. The single-chain insulin of claim 7 , wherein the analogue comprises SEQ ID NO: 30.
9. The single-chain insulin of claim 3 , comprising SEQ ID NO: 8.
10. The single-chain insulin analogue of claim 3 , wherein the C-domain polypeptide ends with Arg-Arg.
11. The single-chain insulin analogue of claim 10 , wherein the analogue is selected from the group consisting of SEQ ID NOs: 5-9, 13-19, 25-29 and 31.
12. The single-chain insulin analogue of claim 3 , wherein the C-domain polypeptide ends with Arg-Arg-Ser-Arg.
13. The single-chain insulin analogue of claim 12 , wherein the analogue is selected from the group consisting of SEQ ID NOs: 20-24 and 30.
14. A method of lowering the blood sugar of a patient, in need thereof the method comprising administering a physiologically effective amount of a single-chain insulin analogue or a physiologically acceptable salt thereof to the patient, wherein the single-chain insulin analogue comprises a B-chain insulin polypeptide sequence connected to an A-chain insulin polypeptide sequence by a C-domain polypeptide sequence; wherein the B-chain insulin polypeptide sequence contains a Cysteine substitution at position B4 relative to the sequence of wild type insulin; wherein the A-chain insulin polypeptide sequence contains a Cysteine substitution at position A10 relative to the sequence of wild type insulin and wherein the C-domain polypeptide sequence is 4 to 11 amino acids long.
15. The method of claim 14 , wherein the analogue comprises any one of SEQ ID NOS: 4-31.
16. The method of claim 14 , wherein the C-domain polypeptide begins with Glu-Glu.
17. The method of claim 16 , wherein the C-domain polypeptide comprises residues 31-36 of SEQ ID NO: 31.
18. The method of claim 17 , wherein the analogue comprises SEQ ID NO: 31.