title: Antigen binding forces of individually addressed single-chain Fv antibody molecules.
abstract: Antibody single-chain Fv fragment (scFv) molecules that are specific for fluorescein have been engineered with a C-terminal cysteine for a directed immobilization on a flat gold surface. Individual scFv molecules can be identified by atomic force microscopy. For selected molecules the antigen binding forces are then determined by using a tip modified with covalently immobilized antigen. An scFv mutant of 12% lower free energy for ligand binding exhibits a statistically significant 20% lower binding force. This strategy of covalent immobilization and measuring well separated single molecules allows the characterization of ligand binding forces in molecular repertoires at the single molecule level and will provide a deeper insight into biorecognition processes.
authors.affiliation: Paul Scherrer Institut, CH-5232 Villigen PSI, Switzerland.
authors.forename: R
authors.initials: R
authors.lastname: Ros
authors.forename: F
authors.initials: F
authors.lastname: Schwesinger
authors.forename: D
authors.initials: D
authors.lastname: Anselmetti
authors.forename: M
authors.initials: M
authors.lastname: Kubon
authors.forename: R
authors.initials: R
authors.lastname: Schäfer
authors.forename: A
authors.initials: A
authors.lastname: Plückthun
authors.forename: L
authors.initials: L
authors.lastname: Tiefenauer
mesh_terms: D000937:Antigen-Antibody Reactions; D000941:Antigens / Q000276:immunology*; D019793:Fluorescein / Q000378:metabolism; D007128:Immunoglobulin Fragments / Q000737:chemistry / Q000276:immunology*; D007135:Immunoglobulin Variable Region / Q000737:chemistry / Q000276:immunology*; D008024:Ligands; D018625:Microscopy, Atomic Force; D008958:Models, Molecular
chemical_list: D000941:Antigens; D007128:Immunoglobulin Fragments; D007135:Immunoglobulin Variable Region; D008024:Ligands; D019793:Fluorescein