title: New chelation strategy allows for quick and clean 99mTc-labeling of synthetic peptides.
abstract: Analogues of bombesin have been synthesized in which a N2S2 (bis-mercaptoacetyl functionalized diaminopropionic acid) or a N3S (mercaptoacetyl-Gly-Gly-Gly) radiometal-chelating center has been incorporated that allows radiolabeling of these peptides with 99mTc without the need for conjugation or harsh reaction conditions. A mild radiolabeling is possible by using an acetyl-moiety as sulfur protecting group, which can be removed by mild hydroxylamine-treatment at room temperature before radiolabeling. Retained receptor binding is demonstrated in competitive binding experiments with 99mTc-radiolabeled peptides and PC-3 cells with bombesin receptors.
authors.affiliation: Department of Clinical Pharmacy and Toxicology, Leiden University Medical Center, Leiden, The Netherlands.
authors.forename: Dik
authors.initials: D
authors.lastname: Blok
authors.forename: Hans I J
authors.initials: HI
authors.lastname: Feitsma
authors.forename: Yvonne M C
authors.initials: YM
authors.lastname: Kooy
authors.forename: Mick M
authors.initials: MM
authors.lastname: Welling
authors.forename: Ferry
authors.initials: F
authors.lastname: Ossendorp
authors.forename: Pieter
authors.initials: P
authors.lastname: Vermeij
authors.forename: Jan W
authors.initials: JW
authors.lastname: Drijfhout
mesh_terms: D001667:Binding, Competitive / Q000187:drug effects; D001839:Bombesin / Q000138:chemical synthesis; D045744:Cell Line, Tumor; D002614:Chelating Agents / Q000737:chemistry*; D004355:Drug Stability; D006801:Humans; D007553:Isotope Labeling; D008297:Male; D010455:Peptides / Q000138:chemical synthesis*; D011471:Prostatic Neoplasms / Q000000981:diagnostic imaging; D011877:Radionuclide Imaging; D019275:Radiopharmaceuticals / Q000378:metabolism; D018004:Receptors, Bombesin / Q000187:drug effects / Q000378:metabolism; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D013667:Technetium / Q000737:chemistry*; D017263:Technetium Tc 99m Mertiatide / Q000378:metabolism
chemical_list: D002614:Chelating Agents; D010455:Peptides; D019275:Radiopharmaceuticals; D018004:Receptors, Bombesin; D017263:Technetium Tc 99m Mertiatide; D013667:Technetium; D001839:Bombesin