Cyclised alpha-conotoxin peptides

1. An oral pharmaceutical preparation consisting of:

at least one synthetically cyclised α-conotoxin peptide having an amide cyclised backbone such that the peptide has no free N- or C-terminus, said peptide comprising four cysteine residues bonded in pairs to form two disulfide bonds, one disulfide bond between cysteine residues I and III and one disulfide bond between cysteine residues II and IV,

wherein the N-terminus of the corresponding linear/noncyclised conotoxin peptide is linked to the C-terminus by a peptide linker, and wherein the corresponding linear/noncyclised α-conotoxin peptide comprises:

SEQ ID NO: 1

Xaa 1  CCS Xaa 2  P Xaa 3  C Xaa 4  Xaa 5  Xaa 6  Xaa 7  Xaa 8

Xaa 9  Xaa 10  C

in which Xaa 1 is glycine or aspartate, Xaa 2 to Xaa 7 represent any naturally occurring or unnatural amino acid, Xaa 8 represents proline, hydroxyproline, serine, or glutamine, Xaa 9 represents aspartate, glutamate, γ-carboxyglutamate, glycine, or asparagine, and Xaa 10 represents any naturally occurring or unnatural amino acid or may be absent in a vehicle which is pharmaceutically suitable for oral administration.

2. The pharmaceutical preparation according to claim 1 wherein Xaa 1 to Xaa 10 are selected as follows:

Xaa 1 is glycine or aspartate,

Xaa 2 is selected from aspartate, asparagine, histidine, tyrosine, arginine or leucine,

Xaa 3 is selected from arginine, proline, alanine, valine or serine,

Xaa 4 is selected from asparagine, alanine, arginine, tyrosine, histidine, phenylalanine, serine, isoleucine or lysine,

Xaa 5 is selected from tyrosine, histidine, alanine, valine, glutamine, glycine, leucine, serine, threonine, asparagine, aspartate, glutamate, lysine or arginine,

Xaa 6 is selected from aspartate, asparagine, serine, threonine, glutamate, glycine, arginine or histidine,

Xaa 7 is selected from histidine, asparagine or tyrosine,

Xaa 8 is selected from proline, hydroxyproline, glutamine or serine,

Xaa 9 is selected from glutamate, γ-carboxyglutamate, aspartate, glycine or asparagine, and,

Xaa 10 is selected from isoleucine, tyrosine, leucine or des-Xaa 10 .

3. The pharmaceutical preparation according to claim 1 wherein Xaa 1 to Xaa 10 are selected as follows:

Xaa 1 is glycine or aspartate,

Xaa 2 is aspartate,

Xaa 3 is arginine,

Xaa 4 is asparagine,

Xaa 5 is tyrosine,

Xaa 6 is aspartate,

Xaa 7 is histidine,

Xaa 8 is proline,

Xaa 9 is glutamate,

and,

Xaa 10 is isoleucine.

4. The pharmaceutical preparation according to claim 1 wherein the corresponding linear/non-cyclised α-conotoxin peptide is Vc 1.1.

5. The pharmaceutical preparation according to any one of claims 1 to 4 wherein the linker is selected such that there are seven amino acid residues between the first and the fourth cysteine residues.

6. The pharmaceutical preparation according to claim 5 wherein the linker comprises glycine and/or alanine residues in addition to any amino acid residues already present in the linear α-conotoxin.

7. The pharmaceutical preparation according to claim 1 wherein the peptide linker is such that between six and eight natural or unnatural amino acids span the distance between cysteine residues I and IV.

8. The pharmaceutical preparation according to claim 1 wherein the synthetically cyclised peptide is selected from:

9. The pharmaceutical preparation according to claim 7 wherein the synthetically cyclised peptide is:

10. A method for the treatment or prevention of pain comprising the step of orally or enterally administering a pharmaceutical preparation consisting of at least one synthetically cyclised α-conotoxin peptide having an amide cyclised backbone such that the peptide has no free N- or C-terminus, said peptide comprising four cysteine residues bonded in pairs to form two disulfide bonds, one disulfide bond between cysteine residues I and III and one disulfide bond between cysteine residues II and IV,

wherein the N-terminus of the corresponding; linear/non-cyclised conotoxin peptide is linked to the C-terminus by a peptide linker, and wherein the corresponding linear/noncyclised α-conotoxin peptide comprises:

SEQ ID NO: 1

Xaa 1  CCS Xaa 2  P Xaa 3  C Xaa 4  Xaa 5  Xaa 6  Xaa 7  Xaa 8

Xaa 9  Xaa 10  C

in which Xaa 1 is glycine or aspartate, Xaa 2 to Xaa 7 represent any naturally occurring or unnatural amino acid, Xaa 8 represents proline, hydroxyproline, serine, or glutamine, Xaa 9 represents aspartate, glutamate, γ-carboxyglutamate, glycine, or asparagine, and Xaa 10 represents any naturally occurring or unnatural amino acid or may be absent,

in a vehicle which is pharmaceutically suitable for oral or enteral administration.

11. The method according to claim 10 wherein the pain is neuropathic pain.

12. The method according to claim 10 wherein the pain is inflammatory pain.

13. The method according to claim 11 wherein the neuropathic pain is diabetic neuropathy pain.

14. A method for accelerating the recovery of nerve damage comprising the step of orally or enterally administering a pharmaceutical preparation consisting of at least one synthetically cyclised α-conotoxin peptide having an amide cyclised backbone such that the peptide has no free N- or C-terminus, said peptide comprising four cysteine residues bonded in pairs to form two disulfide bonds, one disulfide bond between cysteine residues I and III and one disulfide bond between cysteine residues II and IV,

wherein the N-terminus of the corresponding; linear/non-cyclised conotoxin peptide is linked to the C-terminus by a peptide linker, and wherein the corresponding linear/noncyclised α-conotoxin peptide comprises:

SEQ ID NO: 1

Xaa 1  CCS Xaa 2  P Xaa 3  C Xaa 4  Xaa 5  Xaa 6  Xaa 7  Xaa 8

Xaa 9  Xaa 10  C

in which Xaa 1 is glycine or aspartate, Xaa 2 to Xaa 7 represent any naturally occurring or unnatural amino acid, Xaa 8 represents proline, hydroxyproline, serine, or glutamine, Xaa 9 represents aspartate, glutamate, γ-carboxyglutamate, glycine, or asparagine, and Xaa 10 represents any naturally occurring or unnatural amino acid or may be absent,

in a vehicle which is pharmaceutically suitable for oral or enteral administration.

15. A method for the treatment of Alzheimer's disease, schizophrenia, depression, epilepsy, small cell lung carcinoma, cardiovascular disorders, gastric motility disorders, urinary incontinence, nicotine addiction, mood disorders or inflammation comprising the step of orally or enterally administering a pharmaceutical preparation consisting of at least one synthetically cyclised αconotoxin peptide having an amide cyclised backbone such that the peptide has no free N- or C-terminus, said peptide comprising four cysteine residues bonded in pairs to form two disulfide bonds, one disulfide bond between cysteine residues I and III and one disulfide bond between cysteine residues II and IV,

wherein the N-terminus of the corresponding; linear/non-cyclised conotoxin peptide is linked to the C-terminus by a peptide linker, and wherein the corresponding linear/noncyclised α-conotoxin peptide comprises:

SEQ ID NO: 1

Xaa 1  CCS Xaa 2  P Xaa 3  C Xaa 4  Xaa 5  Xaa 6  Xaa 7  Xaa 8

Xaa 9  Xaa 10  C

in which Xaa 1 is glycine or aspartate, Xaa 2 to Xaa 7 represent any naturally or unnatural amino acid, Xaa 8 represents proline, hydroxyproline, serine, or glutamine, Xaa 9 represents aspartate, glutamate, γ-carboxyglutamate, glycine, or asparagine, and Xaa 10 represents any naturally occurring or unnatural amino acid or may be absent,

in a vehicle which is pharmaceutically suitable for oral or enteral administration.