title: Measuring affinity constants of 1450 monoclonal antibodies to peptide targets with a microarray-based label-free assay platform.
abstract: Monoclonal antibodies (mAbs) are major reagents for research and clinical diagnosis. For their inherently high specificities to intended antigen targets and thus low toxicity in general, they are pursued as one of the major classes of new drugs. Yet binding properties of most monoclonal antibodies are not well characterized in terms of affinity constants and how they vary with presentations and/or conformational isomers of antigens, buffer compositions, and temperature. We here report a microarray-based label-free assay platform for high-throughput measurements of monoclonal antibody affinity constants to antigens immobilized on solid surfaces. Using this platform we measured affinity constants of over 1410 rabbit monoclonal antibodies and 46 mouse monoclonal antibodies to peptide targets that are immobilized through a terminal cysteine residue to a glass surface. The experimentally measured affinity constants vary from 10 pM to 200 pM with the median value at 66 pM. We compare the results obtained from the microarray-based platform with those from a benchmarking surface-plasmon-resonance-based (SPR) sensor (Biacore 3000).
authors.affiliation: Department of Physics, University of California, Davis, CA, 95616, USA.
authors.forename: J P
authors.initials: JP
authors.lastname: Landry
authors.affiliation: Epitomics, Inc, Burlingame, CA 94010, USA.
authors.forename: Yaohuang
authors.initials: Y
authors.lastname: Ke
authors.affiliation: Epitomics, Inc, Burlingame, CA 94010, USA.
authors.forename: Guo-Liang
authors.initials: GL
authors.lastname: Yu
authors.affiliation: Department of Physics, University of California, Davis, CA, 95616, USA. Electronic address: xdzhu@physics.ucdavis.edu.
authors.forename: X D
authors.initials: XD
authors.lastname: Zhu
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology*; D000915:Antibody Affinity / Q000276:immunology*; D000937:Antigen-Antibody Reactions / Q000276:immunology*; D000941:Antigens / Q000276:immunology; D057166:High-Throughput Screening Assays / Q000379:methods; D051379:Mice; D040081:Protein Array Analysis / Q000379:methods; D011817:Rabbits; D020349:Surface Plasmon Resonance
chemical_list: D000911:Antibodies, Monoclonal; D000941:Antigens
keywords: Affinity constants; Label-free detection; Microarray; Monoclonal antibody; Oblique-incidence reflectivity difference; Peptide