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) a tripeptide having a sequence XC 1 C 2 ,
wherein X is any natural or non-natural amino acid or amino acid analog,
and further wherein C 1 and C 2 are each individually chosen from a cysteine and a sulfur-containing alpha or beta amino acid; and
(b) a metal atom or ion bound to the sequence XC 1 C 2 ,
wherein the metal atom or ion is bound in a square planar or square pyramidal orientation.
2. The composition of claim 1 , wherein said peptide is linked to a polypeptide, an antibody, a growth factor, or a carbohydrate.
3. The composition of claim 1 , wherein said metal is uranium.
4. The composition of claim 1 , wherein C 1 and C 2 are each cysteine.
5. The composition of claim 1 , wherein X is chosen from asparagine, glutamine, histidine, lysine, and arginine.
6. A method of imaging biological tissue comprising administering a composition according to claim 1 to biological tissue and obtaining an image of said biological tissue.
7. The composition of claim 1 , wherein X is chosen from glutamine, histidine, and lysine.
8. The composition of claim 1 , wherein said metal is selected from a Group 6, Group 7, Group 8, and Group 9 metal.
9. The composition of claim 1 , wherein said peptide is isolated and purified.
10. The composition of claim 1 , wherein said peptide is linked to a growth factor or a carbohydrate.
11. The composition of claim 1 , wherein said peptide is linked to an antibody.
12. The composition of claim 11 , wherein said antibody targets cancer cells.
13. The composition of claim 1 , wherein said metal 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.
14. The composition of claim 13 , wherein said metal is selected from a Group 5, Group 10, Group 11, and Group 12 metal.
15. The composition of claim 14 , wherein said metal is a Group 5 metal.
16. The composition of claim 15 , wherein said Group 5 metal is vanadium.
17. The composition of claim 14 , wherein said metal is a Group 10 metal.
18. The composition of claim 17 , wherein said Group 10 metal is selected from the group consisting of Ni, Pd, and Pt.
19. The composition of claim 14 , wherein said metal is a Group 11 metal.
20. The composition of claim 19 , wherein said Group 11 metal is selected from the group consisting of Cu, Ag, and Au.
21. The composition of claim 14 , wherein said metal is a Group 12 metal.
22. The composition of claim 21 , wherein said Group 12 metal is selected from the group consisting of Zn, Cd, and Hg.
23. The composition of claim 1 , wherein said composition is selected from the group consisting of imaging compositions and therapeutic compositions.
24. The composition of claim 23 , wherein said composition is an imaging composition.
25. The composition of claim 24 , wherein said composition is an imaging composition formulated for use in an imaging technique selected from the group consisting of Computed Tomography (CT), Magnetic Resonance Imaging (MRI), ultrasound, Positron Emission Tomography (PET), Single Photon Emission Computed Tomography (SPECT), Nuclear Magnetic Resonance (NMR), Electron Paramagnetic Resonance (EPR), electron microscopy, and fluorescence imaging.
26. The composition of claim 25 , wherein said imaging technique is selected from the group consisting of PET and SPECT imaging.
27. The composition of claim 23 , wherein said composition is a therapeutic composition.
28. The composition of claim 27 , wherein said therapeutic composition is formulated as a chemotherapy composition.
29. The composition of claim 28 , wherein said chemotherapy composition is formulated for targeted delivery to a cancer cell.
30. A method of preparing a metal-peptide complex comprising:
i) exposing a metal atom or ion to a chelating agent in solution or on a solid support; and
ii) binding a peptide including the sequence XC 1 C 2 with the metal atom or ion to form a metal-XC 1 C 2 complex; wherein X is any non-cysteine amino acid; 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 normatural amino acid;
wherein said metal atom or ion is bound within the sequence XC 1 C 2 in a square planar orientation or square pyramidal orientation; and
wherein said chelating agent is linked to a solid support.
31. A method of preparing a metal-peptide complex comprising:
i) exposing a metal atom or ion to a chelating agent in solution or on a solid support; and
ii) binding a peptide including the sequence XC 1 C 2 with the metal atom or ion to form a metal-XC 1 C 2 complex; wherein X is any non-cysteine amino acid; 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 normatural amino acid;
wherein said metal atom or ion is bound within the sequence XC 1 C 2 in a square planar orientation or square pyramidal orientation; and
wherein said chelating agent is selected from the group consisting of iminodiacetic acid (IDA) and nitrilotriacetic acid (NTA).