Metal abstraction peptide (MAP) tag and associated methods
Compositions comprising a tripeptide having the sequence XC 1 C 2 ; wherein X is any amino acid such that XC 1 C 2 is capable of binding a metal in a square planar orientation or square pyramidal orientation or both; and wherein C 1 and C 2 are the same or different; and wherein C 1 and C 2 individually are chosen from a cysteine and a cysteine-like nonnatural amino acid, as well as metal-XC 1 C 2 complexes and methods for forming such complexes.
1. A composition comprising:
a peptide-metal complex comprising a peptide and a metal atom or ion, wherein the peptide includes the sequence XC 1 C 2 ; wherein X is asparagine, glutamine, histidine, lysine, or arginine and X has at least one attachment to the metal atom or ion of the peptide-metal complex; and wherein C 1 and C 2 are the same or different and each of C 1 and C 2 individually has at least one attachment to the metal atom or ion of the peptide-metal complex; and wherein C 1 and C 2 individually are chosen from a cysteine, a sulfur-containing alpha or beta amino acid, and a cysteine-like nonnatural amino acid,
wherein the peptide-metal complex has a dissociation constant at least as high as when the peptide-metal complex has a square planar or square pyramidal orientation,
wherein all attachments between the peptide of the peptide-metal complex and the metal atom or ion of the peptide-metal complex occur within the sequence XC 1 C 2 .
2. The composition of claim 1 , wherein said metal atom or ion is bound to the peptide with greater than 90% retention for 6 hours.
3. The composition of claim 1 , wherein said metal atom or ion is bound to the peptide with greater than 90% retention upon treatment with strong acid.
4. The composition of claim 1 , wherein said metal atom or ion is bound to the peptide essentially irreversibly at pH 7.4.
5. The composition of claim 1 , wherein said metal atom or ion is bound to the peptide with a dissociation constant which is greater than the dissociation constant of the metal atom or ion with the sequence GGH.
6. The composition of claim 1 , wherein C 1 and C 2 are each cysteine.
7. The composition of claim 1 , wherein said metal atom or ion is selected from a Group 3 metal, a Group 5 metal, a Group 6 metal, a Group 7 metal, a Group 8 metal, a Group 9 metal, a Group 10 metal, a Group 11 metal, a Group 12 metal, a Group 13 metal, a Group 14 metal, and a Group 15 metal.
8. The composition of claim 1 , wherein said metal atom or ion is vanadium.
9. The composition of claim 1 , wherein the metal atom or ion is Cu.
10. The composition of claim 1 , wherein said metal atom or ion is Zn.
11. The composition of claim 1 , wherein said peptide-metal complex is isolated and purified.
12. The composition of claim 1 , wherein said peptide-metal complex is included in the sequence of a polypeptide or protein.
13. The composition of claim 1 , wherein said composition is selected from the group consisting of imaging compositions and therapeutic compositions.
14. The composition of claim 1 , wherein said metal atom or ion is Ni.
15. The composition of claim 1 , wherein said metal atom or ion is Pd.
16. The composition of claim 1 , wherein said metal atom or ion is Pt.
17. The composition of claim 1 , wherein said metal atom or ion is Ag.
18. The composition of claim 1 , wherein said metal atom or ion is Au.
19. The composition of claim 1 , wherein said metal atom or ion is bound to the peptide with greater than 90% retention after treatment with high temperature.
20. The composition of claim 19 , wherein said high temperature is about 90° C. for less than 6 hours.
21. The composition of claim 1 , wherein said metal atom or ion is bound to the peptide with greater than 90% retention upon treatment with aqueous high salt conditions.
22. The composition of claim 21 , wherein said aqueous high salt conditions are about 5.6M guanidinium hydrochloride for less than 6 hours.
23. The composition of claim 1 , wherein said peptide-metal complex is linked to a protein, a polypeptide, an antibody, a growth factor, or a carbohydrate.
24. The composition of claim 23 , wherein said peptide-metal complex is linked to an antibody.
25. A composition comprising:
a peptide-metal complex comprising a peptide and a metal atom or ion, wherein the peptide includes the sequence XC 1 C 2 ; wherein X is any non-cysteine amino acid and X has at least one attachment to the metal atom or ion of the peptide-metal complex; and wherein C 1 and C 2 are the same or different and each of C 1 and C 2 individually has at least one attachment to the metal atom or ion of the peptide-metal complex; and wherein C 1 and C 2 individually are chosen from a cysteine, a sulfur-containing alpha or beta amino acid, and a cysteine-like nonnatural amino acid,
wherein the peptide-metal complex has a dissociation constant at least as high as when the peptide-metal complex has a square planar or square pyramidal orientation,
wherein all attachments between the peptide of the peptide-metal complex and the metal atom or ion of the peptide-metal complex occur within the sequence XC 1 C 2 ,
wherein the metal atom or ion in the peptide-metal complex is Ni, Pd, Pt, Cu, Ag, Au, or Zn.
26. The composition of claim 25 , wherein said metal atom or ion is Ni.
27. The composition of claim 25 , wherein said metal atom or ion is Pd.
28. The composition of claim 25 , wherein said metal atom or ion is Pt.
29. The composition of claim 25 , wherein said metal atom or ion is Cu.
30. The composition of claim 25 , wherein said metal atom or ion is Ag.
31. The composition of claim 25 , wherein said metal atom or ion is Au.
32. The composition of claim 25 , wherein said metal atom or ion is Zn.
33. The composition of claim 25 , wherein C 1 and C 2 are each cysteine.
34. The composition of claim 25 , wherein said peptide-metal complex is linked to an antibody.
35. The composition of claim 25 , wherein said peptide-metal complex is included in the sequence of a polypeptide or protein.