title: Characterization of hapten binding to immunoconjugates by electrospray ionization mass spectrometry.
abstract: Electrospray ionization mass spectrometry (ESI-MS) has been used to characterize the covalent binding of different haptens to the enzyme glucose 6-phosphate dehydrogenase. The technique allows one to directly observe the relative amounts of each conjugated species present in a mixture, as well as the average hapten number. These measurements are useful for optimizing reaction conditions to yield a more precisely defined product for use in immunoassays. The results obtained show that ESI-MS with a quadrupole analyzer can be successfully used to analyze mixtures of derivatized proteins in the molecular weight range of 50-60 kDa, where the modifying hapten has a molecular weight as low as 130 Da.
authors.affiliation: Syntex Discovery Research and Syva Co., Palo Alto, California 94304.
authors.forename: K M
authors.initials: KM
authors.lastname: Straub
authors.forename: M J
authors.initials: MJ
authors.lastname: Levy
mesh_terms: D001665:Binding Sites; D002220:Carbamazepine / Q000737:chemistry / Q000378:metabolism; D004076:Digoxigenin / Q000737:chemistry / Q000378:metabolism; D005954:Glucosephosphate Dehydrogenase / Q000737:chemistry / Q000378:metabolism; D006241:Haptens / Q000737:chemistry / Q000378:metabolism*; D018796:Immunoconjugates / Q000737:chemistry / Q000378:metabolism*; D066298:In Vitro Techniques; D013058:Mass Spectrometry / Q000379:methods; D015394:Molecular Structure; D008970:Molecular Weight; D013974:Thyroxine / Q000031:analogs & derivatives / Q000737:chemistry / Q000378:metabolism; D014635:Valproic Acid / Q000737:chemistry / Q000378:metabolism
chemical_list: D006241:Haptens; D018796:Immunoconjugates; D002220:Carbamazepine; D014635:Valproic Acid; D005954:Glucosephosphate Dehydrogenase; D004076:Digoxigenin; D013974:Thyroxine