Radiolabeled annexins
Radiolabeled annexin and modified annexin conjugates useful for imaging vascular thrombi are described. Methods for making and using such radiolabeled annexin conjugates are also provided.
1. A conjugate comprising:
an annexin;
a N x S y chelating compound, wherein x is an integer from 2–4 and y is 1–4, or a N 4 chelating compound; and
a hexose moiety recognized by a mammalian liver receptor, wherein the hexose is conjugated to the annexin directly or via the chelating compound and the chelating compound is conjugated to the annexin directly or via the hexose moiety,
wherein the annexin is not modified to provide an accessible sulfhydryl group to which the hexose moiety or the chelating compound is conjugated.
2. The conjugate of claim 1 , wherein the hexose moiety comprises a cluster containing at least three hexose residues connected in a branched configuration, and wherein the cluster is conjugated via a single point of attachment to the annexin.
3. The conjugate of claim 2 , wherein the hexose residues are independently selected from the group consisting of galactose, mannose, mannose 6-phosphate, N-acetylglucosamine, pentamannosyl phosphate, glucose, N-galactosamine, N-acetylgalactosamine, thioglycosides of galactose, D-galactosides and glucosides.
4. The conjugate of claim 3 , wherein the hexose residue is N-acetylgalactosamine.
5. The conjugate of claim 4 , wherein the hexose residue is N-acetylgalactosamine, and wherein the cluster comprises:
wherein X is H or CH 3 .
6. The conjugate of claim 1 , wherein the annexin is annexin V.
7. The conjugate of claim 1 , wherein the chelating compound comprises a N 4 chelating compounds.
8. The conjugate of claim 1 , wherein the chelating compound comprises a N 3 S chelating compound.
9. The conjugate of claim 1 , wherein the chelating compounds comprises a N 2 S 2 chelating compound.
10. The conjugate of claim 9 , wherein the chelating compound has the following structure:
wherein T is H, CH 3 or a functional group for conjugating an annexin or a hexose moiety and n is 0 or 1.
11. The conjugate of claim 1 , wherein the conjugate has the following configuration:
annexin-hexose-chelating compound.
12. The conjugate of claim 1 wherein the conjugate has the following configuration:
annexin-chelating compound-hexose.
13. The conjugate of claim 1 , wherein the conjugate further comprises a linker recognized by a liver enzyme such that the linker is enzymatically cleavable.
14. The conjugate of claim 1 , wherein the conjugate further comprises a cleavable linker which is selected from the group consisting of monosaccharides, polysaccharides, polyamino acids, hydroxyakyl acrylamides, polyethelene glycol based hydrophilic polymers, biodegradable polymers containing an ether or ester linkage, dextran or hemisuccinyl esters.
15. The conjugate of claim 1 , wherein the conjugate further comprises a radionuclide complexed by the chelating compound.
16. The conjugate of claim 15 , wherein the radionuclide is selected from the group consisting of Cu-64, Ga-67, Ga-68, Re-186, Re-188, Cu-67, Tc-99m, Tc-94, Ru-95 and In-111.
17. The conjugate of claim 16 , wherein the radionuclide is technetium-99m.