title: The synthesis and use of activated N-benzyl derivatives of diethylenetriaminetetraacetic acids: alternative reagents for labeling of antibodies with metal ions.
abstract: A series of bifunctional chelating agents--substituted benzyl derivatives of diethylenetriaminetetra acids--was synthesized. These agents were used to label antibodies with a lanthanide, Eu3+. The stabilities of their antibody conjugates were evaluated under different conditions and the dissociation rates of Eu3+ were measured at pH 3.2, which is used for fluorescence enhancement in time-resolved fluoroimmunoassays. The synthesized complexing agents were also compared to other reagents used for metal labelings, to diethylenetriaminepentaacetic acid-dianhydride, and to p-isothiocyanatophenyl-EDTA. The asymmetric p-isothiocyanatobenzyl derivative of diethylenetriaminetetraacetic acid-Eu3+ showed reasonably good stability at neutral pH but released Eu3+ rapidly in the acidic fluorescence enhancement solution. This makes it an optimal choice for chelate labeling in dissociation-based time-resolved fluoroimmunoassays.
authors.affiliation: Wallac Chemical Laboratories, Turku, Finland.
authors.forename: V M
authors.initials: VM
authors.lastname: Mukkala
authors.forename: H
authors.initials: H
authors.lastname: Mikola
authors.forename: I
authors.initials: I
authors.lastname: Hemmilä
mesh_terms: D000818:Animals; D000906:Antibodies / Q000276:immunology; D000915:Antibody Affinity; D001593:Benzyl Compounds / Q000138:chemical synthesis*; D002614:Chelating Agents / Q000138:chemical synthesis*; D004492:Edetic Acid / Q000031:analogs & derivatives / Q000138:chemical synthesis; D005063:Europium; D015200:Fluoroimmunoassay; D006801:Humans; D007074:Immunoglobulin G / Q000276:immunology; D007536:Isomerism; D007811:Lanthanum; D051379:Mice; D004369:Pentetic Acid / Q000031:analogs & derivatives* / Q000138:chemical synthesis; D011817:Rabbits
chemical_list: D000906:Antibodies; D001593:Benzyl Compounds; D002614:Chelating Agents; D007074:Immunoglobulin G; C060068:diethylenetriaminetetraacetic acid; D005063:Europium; D007811:Lanthanum; D004369:Pentetic Acid; D004492:Edetic Acid