title: Radiolabeling of phosphatidylserine-binding peptides with prosthetic groups N-[6-(4-[18F]fluorobenzylidene)aminooxyhexyl]maleimide ([18F]FBAM) and N-succinimidyl-4-[18F]fluorobenzoate ([18F]SFB).
abstract: The widely used (18)F-prosthetic group N-succinimidyl-4-[(18)F]fluorobenzoate ([(18)F]SFB) and the recently developed N-[6-(4-[(18)F]fluorobenzylidene)aminooxyhexyl]maleimide ([(18)F]FBAM) were investigated for radiolabeling of two representative phosphatidylserine-binding peptides. The prosthetic groups were compared with respect to required reactions conditions for optimum labeling, radiolabeling yield and chemoselectivity. The N-terminus labeled product produced by reaction of [(18)F]SFB with binding peptide LIKKPF was produced in 18% radiochemical yield while no N-terminus labeled product could be isolated following [(18)F]SFB reaction with PDGLSR. When the peptides were modified by addition of a cysteine residue at the N-terminus they provided almost quantitative radiochemical yields with [(18)F]FBAM. Results indicate that for the peptides in this study, [(18)F]FBAM is a more useful prosthetic group compared to [(18)F]SFB due to its excellent chemoselectivity and high radiochemical yield.
authors.affiliation: Department of Oncology, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Canada. jkapty@ualberta.ca
authors.forename: Janice
authors.initials: J
authors.lastname: Kapty
authors.forename: Torsten
authors.initials: T
authors.lastname: Kniess
authors.forename: Frank
authors.initials: F
authors.lastname: Wuest
authors.forename: John R
authors.initials: JR
authors.lastname: Mercer
mesh_terms: D001565:Benzoates / Q000737:chemistry*; D005462:Fluorine Radioisotopes / Q000737:chemistry*; D007553:Isotope Labeling / Q000379:methods*; D008301:Maleimides / Q000737:chemistry*; D010455:Peptides / Q000138:chemical synthesis / Q000737:chemistry*; D010718:Phosphatidylserines / Q000737:chemistry*; D011485:Protein Binding; D019275:Radiopharmaceuticals / Q000737:chemistry; D013388:Succinimides / Q000737:chemistry*
chemical_list: D001565:Benzoates; D005462:Fluorine Radioisotopes; D008301:Maleimides; C518594:N-(6-(4-fluorobenzylidene)aminooxyhexyl)maleimide; D010455:Peptides; D010718:Phosphatidylserines; D019275:Radiopharmaceuticals; D013388:Succinimides; C075713:N-succinimidyl-4-fluorobenzoate