Synthesis gallium labelling and characterization of P04087 a functionalized phosphatidylserine-binding peptide

摘要

BackgroundRadiolabeled phosphatidylserine (PS)-binding peptides represent an innovative strategy for molecular imaging of apoptosis and thrombus. The hexapeptide PGDLSR was described as a selective and high affinity ligand for PS. In this work, we synthesized and evaluated a gallium labelled-PGDLSR peptide as a potential and selective radiopharmaceutical for nuclear imaging. PGDLSR-β-alanine-NODAGA () was prepared using Fmoc-based synthesis and then chelated with cold gallium, ⁶⁸Ga and ⁶⁷Ga. The affinity of Ga- for PS was evaluated by a competitive binding assay using biotinylated AnnexinV. The in vitro stability of the radiotracer was checked at room temperature and after incubation in human serum at 37 °C with and without a metalloprotease inhibitor. The in vivo binding of ⁶⁷Ga- to phosphatidylserine was evaluated in a rat model of infective endocarditis.