Imaging beta cell mass
The present disclosure provides compositions and methods based on peptide-detectable agent conjugates that are useful for imaging beta cell mass.
1. A composition comprising the peptide sequence SEQ ID NO:2, wherein the amino acid at position 12 is an unnatural amino acid, wherein the unnatural amino acid is (S)-2-amino-4-pentynoic acid.
2. A composition comprising the peptide sequence SEQ ID NO:3, wherein the amino acid at position 12 is cysteine.
3. The composition of claim 2 , wherein the cysteine is modified with a linker comprising a maleimide at a first end and a tetrazine at a second end.
4. The composition of claim 3 , wherein the cysteine has reacted with the maleimide via a 1,2-addition reaction.
5. The composition of claim 3 , wherein the tetrazine has reacted with a strained alkene attached to a detectable agent via an inverse electron demand Diels-Alder reaction.
6. The composition of claim 5 , wherein the strained alkene is trans-cyclooctene.