CA2373680C

Protection of endogenous therapeutic peptides from peptidase activity through conjugation to blood components

Abstract

A method for protecting a peptide from peptidase activity in vivo, the peptide being composed of between 2 and 50 amino acids and having a C-terminus and an N-terminus and a C-terminus amino acid and an N-terminus amino acid is described. In the first step of the method, the peptide is modified by attaching a reactive group to the C-terminus amino acid, to the N-terminus amino acid, or to an amino acid located between the N-terminus and the C- terminus, such that the modified peptide is capable of forming a covalent bond in vivo with a reactive functionality on a blood component. In the next step, a covalent bond is formed between the reactive group and a reactive functionality on a blood component to form a peptide-blood component conjugate, thereby protecting said peptide from peptidase activity. The final step of the method involves the analyzing of the stability of the peptide- blood component conjugate to assess the protection of the peptide from peptidase activity.

CA2373680C, drawing sheet 1
Sheet 1 of 49

Term

Term ended

Expired 17 May 2020, 6.4 years ago.

  1. Priority
  2. Filed
  3. Granted
  4. Expired
  5. Today

48 claims: 23 independent, 25 dependent

  1. 1
    CA 02373680 2007-03-28 182 1. A method of synthesizing a modified therapeutic peptide capable of forming a peptidase-stabilized therapeutic peptide conjugate, the peptide comprising between 3 and 50 amino acids and having a carboxy terminal amino acid, an amino terminal amino acid, the method comprising the steps of:a) synthesizing the peptide from the carboxy terminal amino acid or the amino terminal amino acid;b) sequentially and selectively oxidizing any pair of cysteine residues in said therapeutic peptide to form disulfide bridges in said therapeutic peptide;c) attaching a protecting group to any remaining cysteine residue that do not form said disulfide bridges in said therapeutic peptide;and d) coupling a reactive group such that the therapeutic activity of the peptide is retained to the carboxy terminal amino acid, to the amino terminal amino acid, or to an amino acid between the carboxy terminal amino acid and the amino terminal amino acid, wherein the reactive group is capable of reacting with an amino group, a hydroxyl group or a thiol group on a blood component to form a covalent bond therewith.
  2. 4
    A method as claimed in any one of claims 1 to 3, further comprising bonding a lysine residue to said peptide, wherein the reactive group is coupled to the peptide via said lysine residue.
  3. 5
    A method as claimed in any one of claims 1 to 4 wherein the reactive group CA 02373680 2007-03-28 183 is coupled to the carboxy terminal amino acid of the peptide.
  4. 6
    A method as claimed in any one of claims 1 to 5 wherein the peptide does not contain a cysteine.
  5. 7
    A method as claimed in any one of claims 1 to 5 wherein the therapeutic peptide contains two cysteines, the two cysteines are oxidized to form a disulfide bridge, and the reactive group is coupled to the peptide.
  6. 8
    A method as claimed in any one of claims 1 to 7 wherein the peptide is synthesized from the carboxy terminal amino acid.
  7. 9
    A method of synthesizing a modified therapeutic peptide and forming a peptidase-stabilized therapeutic peptide conjugate, the peptide comprising between 3 and 50 amino acids and having a carboxy terminal amino acid and an amino terminal amino acid, the method comprising the steps of:a) synthesizing the peptide from the carboxy terminal amino acid;b) coupling a maleimido-containing group such that the therapeutic activity of the peptide is retained, to the carboxy terminal amino acid, the amino terminal amino acid, an amino acid between the carboxy terminal amino acid and the amino terminal amino acid, and c) reacting the maleimido-containing group with a thiol group of a blood component to form a covalent bond therewith.
  8. 12
    A method as claimed in any one of claims 9 to 11 wherein said reacting step occurs ex vivo. CA 02373680 2007-03-28 184
  9. 13
    A method for protecting from peptidase degradation a therapeutic peptide, said peptide comprising between 3 and 50 amino acids and having a carboxy terminus and an amino terminus and a carboxy terminal amino acid and an amino terminal amino acid, comprising:a) modifying said peptide by coupling a reactive group such that the therapeutic activity of the peptide is retained to the carboxy terminal amino acid, to the amino terminal amino acid, or to an amino acid located between the amino terminal amino acid and the carboxy terminal amino acid, the reactive group being capable of forming a covalent bond with a reactive functionality on a blood component;and, b) forming a covalent bond between said reactive group and a reactive functionality on a blood component to form a modified peptide-blood component conjugate, thereby protecting said peptide from peptidase degradation.
  10. 15
    A method according to claims 13 or 14, wherein said reactive group is a maleimide group.
  11. 17
    A method according to any of claims 13 to 15, wherein said reactive group is attached to said peptide via a linking group.
  12. 20
    A method for protecting from peptidase degradation a therapeutic peptide, said peptide comprising between 3 and 50 amino acids and having a therapeutically active region of amino acids and a less therapeutically active region of amino acids, comprising:a) identifying said therapeutically active region of amino acids;b) modifying said peptide at an amino acid included in said less therapeutically active region by coupling thereto a reactive group to said amino acid to form a modified peptide, such that said modified peptide has therapeutic activity, the reactive group being capable of forming a covalent bond with a reactive functionality on a blood component;and c) forming a covalent bond between said reactive group and a reactive functionality on a blood component to form a peptide-blood component conjugate, thereby protecting said peptide from peptidase degradation.
  13. 28
    A method for selecting a therapeutic peptide protected from peptidase degradation in vivo from a plurality of therapeutic peptides comprising between 3 and 50 amino acids, having a carboxy terminus and an amino terminus, and a carboxy terminal amino acid and an amino terminal amino acid, said peptides having been modified by coupling a reactive group to the carboxy terminal amino acid, to the amino terminal amino acid, or to an amino acid located between the amino terminal acid and the carboxy terminal amino acid; the method comprising:a) forming a covalent bond between said reactive group and a reactive functionality on albumin having all its disulfide bridges intact to form peptidealbumin conjugates;and b) analyzing the stability of said peptide-albumin conjugates toward peptidase degradation and verifying if the peptide-albumin conjugates retains the therapeutic activity of the unconjugated therapeutic peptide.
  14. 34
    Use of a modified therapeutic peptide for in vivo synthesis of a peptidase stabilized therapeutic peptide-blood component conjugate, wherein said peptide comprises between 3 and 50 amino acids and having a carboxy terminal amino acid and an amino terminal amino, said peptide being coupled such that the therapeutic activity of the peptide is retained to a maleimido-containing group by the carboxy terminal amino acid, the amino terminal amino acid, an amino acid between the carboxy terminal amino acid and the amino terminal amino acid, said conjugate being characterized by a covalent bond between said peptide and thiol group of said blood component in an individual in need thereof.
  15. 37
    Use of a therapeutic peptide to form a modified peptide-blood component conjugate in vivo to treat an individual in need thereof, wherein said peptide comprises between 3 and 50 amino acids and having a carboxy terminus and an amino terminus and a carboxy terminal amino acid and an amino terminal amino acid said peptide being modified by coupling a reactive group such that the therapeutic activity of the peptide is retained to the carboxy terminal amino acid, to the amino terminal amino acid, or to an amino acid located between the amino CA 02373680 2007-03-28 188 terminal amino acid and the carboxy terminal amino acid to form a covalent bond between said reactive group and a reactive functionality on a blood component thereby protecting said peptide from peptidase degradation.
  16. 40
    A use as claimed in any one of claims 37 to 38, wherein said reactive group is attached to said peptide via a linking group.
  17. 41
    A use as claimed in any one of claims 37 to 40, wherein said blood component is albumin.
  18. 42
    A use as claimed in any one of claims 37 to 41, wherein one or more of said amino acids is synthetic.
  19. 43
    Use of therapeutic peptide to form a modified peptide-blood component conjugate in vivo to treat an individual in need thereof, wherein said peptide comprises between 3 and 50 amino acids and having a therapeutically active region of amino acids and a less therapeutically active region of amino acids said peptide being modified at an amino acid included in said less therapeutically active region by coupling thereto a reactive group to said amino acid to form a modified peptide such that said modified peptide has therapeutic activity, to form a covalent bond between said reactive group and a reactive functionality on a blood component, thereby protecting said peptide from peptidase degradation.
  20. 45
    A use as claimed in any one of claims 43 or 44, wherein said reactive group is a maleimido group.
  21. 46
    A use as claimed in any one of claims 43 to 45, wherein said reactive group is coupled to said peptide via a lysine.
  22. 47
    A use as claimed in any one of claims 43 to 45, wherein said reactive 15 group is coupled to said peptide via a linking group.
  23. 48
    A use as claimed in any one of claims 43 to 47, wherein said blood component is albumin. 20 49. A use as claim in any one of claims 43 to 48, wherein one or more of said amino acids is synthetic.
Independent claims23