Site-Specific Small Molecule Labeling of an Internal Loop in JC Polyomavirus Pentamers Using the π-Clamp-Mediated Cysteine Conjugation

Site-specific π-clamp-mediated radiosynthesis of 68Ga and 18F PET radiopharmaceuticals

The π-clamp-mediated conjugation method, which enables site-specific modification of cysteine residues, is a promising strategy for developing well-defined radiolabelled biomolecules for positron emission tomography (PET) imaging. We have applied this method to site-specifically attach the macrocyclic chelators "NODA" and "NODAGA" to the somatostatin receptor 2-targeted peptide, octreotate. The resulting novel NODA-octreotate and NODAGA-octreotate compounds can be radiolabelled with either [18F]AlF- or [68Ga]Ga3+ respectively. In vivo PET imaging shows that the [68Ga]Ga3+-labelled derivative exhibits high stability and favourable pharmacokinetic properties.

Perfluoroaryl and Perfluoroheteroaryl Reagents as Emerging New Tools for Peptide Synthesis, Modification and Bioconjugation

Peptides and proteins are becoming increasingly valuable as medicines, diagnostic agents and as tools for biomedical sciences. Much of this has been underpinned by the emergence of new methods for the manipulation and augmentation of native biomolecules. Perfluoroaromatic reagents are perhaps one of the most diverse and exciting tools with which to modify peptides and proteins, due principally to their nucleophilic substitution chemistry, high electron deficiency and the ability for their reactivity to be tuned towards specific nucleophiles. As discussed in this minireview, in recent years, perfluoroaromatic reagents have found applications as protecting groups or activating groups in peptide synthesis and as orthogonal handles for peptide modification. Furthermore, they have applications in chemoselective 'tagging', stapling and bioconjugation of peptides and proteins, as well as tuning of 'drug-like' properties. This review will also explore possible future applications of these reagents in biological chemistry.