title: Labeling proteins using aryl iodide acylation agents: influence of meta vs para substitution on in vivo stability.
abstract: The effect of para vs meta substitution on the biological behavior of an intact antibody and an F(ab')2 fragment was investigated. Paired-label studies were performed using 81C6 IgG and OC 125 F(ab')2 labeled using the N-succinimidyl esters of both p-[125I]- and m-[131I]iodobenzoate as well as with the potential catabolites, p-[125I]- and m-[131I]iodobenzoic acid. In all 3 studies, up to 55% lower uptake of 131I in thyroid and stomach was observed, suggesting that the m-substituted species were more inert to dehalogenation in vivo.
authors.affiliation: Department of Radiology, Duke University Medical Center, Durham, NC 27710.
authors.forename: P K
authors.initials: PK
authors.lastname: Garg
authors.forename: S K
authors.initials: SK
authors.lastname: Slade
authors.forename: C L
authors.initials: CL
authors.lastname: Harrison
authors.forename: M R
authors.initials: MR
authors.lastname: Zalutsky
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology* / Q000493:pharmacokinetics; D004355:Drug Stability; D007140:Immunoglobulin Fab Fragments / Q000276:immunology / Q000493:pharmacokinetics; D007457:Iodine Radioisotopes; D007463:Iodobenzoates / Q000138:chemical synthesis* / Q000493:pharmacokinetics; D007553:Isotope Labeling / Q000379:methods*; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D009363:Neoplasm Proteins / Q000276:immunology; D014018:Tissue Distribution
chemical_list: D000911:Antibodies, Monoclonal; D007140:Immunoglobulin Fab Fragments; D007457:Iodine Radioisotopes; D007463:Iodobenzoates; D009363:Neoplasm Proteins; C062338:N-succinimidyl 4-iodobenzoate; C062337:N-succinimidyl 3-iodobenzoate