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:
an isolated peptide including the sequence XC 1 C 2 ; 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 nonnatural amino acid; and
a metal atom or ion bound within the sequence XC 1 C 2 such that the metal atom or ion is bound in a square planar orientation or square pyramidal orientation.
2. The composition of claim 1 wherein X is chosen from asparagine, glutamine, histidine, lysine, and arginine.
3. The composition of claim 1 , wherein said peptide is included in a polypeptide.
4. The composition of claim 1 , wherein said peptide is linked to a non-peptide entity.
5. The composition of claim 1 , wherein the metal atom or ion is selected from the group consisting of Pt and Pd.
6. The composition of claim 1 , wherein the metal atom or ion is selected from the group consisting of Zn, Ni, Au, Ag, Pb, and Fe.
7. The composition of claim 1 , wherein the metal atom or ion is a radioisotope.
8. The composition of claim 1 , wherein the metal atom or ion is Cu.
9. The composition of claim 8 , wherein the metal atom or ion is 62 Cu.
10. 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 nonnatural 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.
11. The method of claim 10 wherein X is chosen from asparagine, glutamine, histidine, lysine, and arginine.
12. The method of claim 10 , wherein the metal atom or ion is selected from the group consisting of Zn, Ni, Pt, Pd, Au, Ag, Pb, and Fe.
13. The method of claim 10 , wherein the metal atom or ion is a radioisotope.
14. The method of claim 10 , wherein said peptide is linked to a non-peptide entity.
15. The method of claim 10 , wherein said peptide is included in a polypeptide.
16. The method of claim 10 , wherein said chelator is linked to a solid support.
17. The method of claim 10 , wherein said chelator is selected from the group consisting of iminodiacetic acid (IDA) and nitrilotriacetic acid (NTA).
18. The method of claim 10 , wherein the metal atom or ion is Cu.
19. The method of claim 18 , wherein the metal atom or ion is 62 Cu.
20. A method of imaging with a metal-peptide complex comprising administering a metal-peptide complex prepared according to claim 10 to a biological sample and obtaining an image.
21. The method of claim 20 , wherein said imaging occurs in a subject.