title: Polymer-supported organotin reagent for prosthetic group labeling of biological macromolecules with radioiodine.
abstract: In this study, we investigated the use of poly-mer-bound precursor for generating a radiolabeled prosthetic group to be used for conjugate labeling of biological macromolecules. For the approach, a trialkyltin chloride in which the tin was bound to a hydrophilic PEG-based resin support via one of the alkyl groups was synthesized. This resin was then used to prepare a resin-bound trialkyltin benzoic acid, which in some cases was further derivatized on-resin by converting it to a succinimidyl ester. Exposure of the resin-bound compounds to electrophilic radioiodine (¹²⁵I) in either an aqueous or methanol solvent liberated either free radiolabeled [¹²⁵I]iodobenzoic acid or its succinimidyl ester without co-release of the resin-bound precursors. Radiochemical yield was between 35% and 75%, depending on the solvent system and precursor. As example applications for the released compounds, the amine-reactive N-succinimidyl-[¹²⁵I]iodobenzoate prosthetic group was used for conjugate radiolabeling of a peptide, tomato plant systemin, and two proteins, albumin and IgG antibody. These results demonstrate that resin-bound organotin precursors in which the compound to be labeled is tethered to the support via the tin group to be substituted can be used to produce radioiodine-labeled aromatic prosthetic groups in good specific activity without the need for HPLC purification. This solid-phase approach is potentially adaptable to kit-formulation for performing conjugate radiolabeling of biological macromolecules.
authors.affiliation: Medical Department, Brookhaven National Laboratory, Upton, New York 11973, USA. gifforda@bnl.gov
authors.forename: Andrew N
authors.initials: AN
authors.lastname: Gifford
authors.forename: Sonja
authors.initials: S
authors.lastname: Kuschel
authors.forename: Colleen
authors.initials: C
authors.lastname: Shea
authors.forename: Joanna S
authors.initials: JS
authors.lastname: Fowler
mesh_terms: D000818:Animals; D001565:Benzoates / Q000737:chemistry; D002417:Cattle; D007074:Immunoglobulin G / Q000737:chemistry; D007457:Iodine Radioisotopes / Q000737:chemistry; D007553:Isotope Labeling / Q000379:methods*; D046911:Macromolecular Substances / Q000737:chemistry*; D009947:Organotin Compounds / Q000737:chemistry*; D010455:Peptides / Q000737:chemistry; D011108:Polymers / Q000737:chemistry*; D012710:Serum Albumin, Bovine / Q000737:chemistry
chemical_list: D001565:Benzoates; D007074:Immunoglobulin G; D007457:Iodine Radioisotopes; D046911:Macromolecular Substances; D009947:Organotin Compounds; D010455:Peptides; D011108:Polymers; D012710:Serum Albumin, Bovine; C073704:systemin