posted on 2024-03-14, 04:05authored byPragalath Sadasivam, Shivashankar Khanapur, Siddesh V. Hartimath, Boominathan Ramasamy, Peter Cheng, Chin Zan Feng, David Green, Christopher Davis, Julian L. Goggi, Edward G. Robins, Ran Yan
Protein-based 18F-PET tracers offer new possibilities
in early disease detection and personalized medicine. Their development
relies heavily on the availability and effectiveness of 18F-prosthetic groups. We prepared and evaluated a novel arginine-selective
prosthetic group, 4-[18F]fluorophenylglyoxal ([18F]FPG). [18F]FPG was radiosynthesized by a one-pot, two-step
procedure with a non-decay-corrected (n.d.c.) isolated radiochemical
yield (RCY) of 41 ± 8% (n = 10). [18F]FPG constitutes a generic tool for 18F-labeling of various
proteins, including human serum albumin (HSA), ubiquitin, interleukin-2,
and interleukin-4 in ∼30–60% n.d.c. isolated RCYs. [18F]FPG conjugation with arginine residues is highly selective,
even in the presence of a large excess of lysine, cysteine, and histidine.
[18F]FPG protein conjugates are able to preserve the binding
affinity of the native proteins while also demonstrating excellent in vivo stability. The [18F]FPG-HSA conjugate
has prolonged blood retention, which can be applied as a potential
blood pool PET imaging agent. Thus, [18F]FPG is an arginine-selective
bioconjugation reagent that can be effectively used for the development
of 18F-labeled protein radiopharmaceuticals.