Switching the Chemoselectivity in the Preparation of [F]FNA--CooP, a Free Thiol-Containing Peptide for Targeted Positron Emission Tomography Imaging of Fatty Acid Binding Protein 3.

Fatty acid binding protein 3 (FABP3) is expressed both in tumor cells and in the tumor vasculature, making it a potential target for medical imaging and therapy. In this study, we aimed to radiolabel a CooP peptide with a free amino and thiol group, and evaluate the radiolabeled product [F]FNA--CooP for imaging FABP3 expression in breast cancer brain metastases by positron emission tomography. [F]FNA--CooP was prepared by highly chemoselective -acylation and characterized using different chemical approaches.

Radiosynthesis, structural identification and in vitro tissue binding study of [F]FNA-S-ACooP, a novel radiopeptide for targeted PET imaging of fatty acid binding protein 3.

Background: Fatty acid binding protein 3 (FABP3) is a target with clinical relevance and the peptide ligand ACooP has been identified for FABP3 targeting. ACooP is a linear decapeptide containing a free amino and thiol group, which provides opportunities for conjugation. This work is to develop methods for radiolabeling of ACooP with fluorine-18 (F) for positron emission tomography (PET) applications, and evaluate the binding of the radiolabeled ACooP in human tumor tissue sections with high FABP3 expression.