title: Direct optical detection of protein-ligand interactions.
abstract: Direct optical detection provides an excellent means to investigate interactions of molecules in biological systems. The dynamic equilibria inherent to these systems can be described in greater detail by recording the kinetics of a biomolecular interaction. Optical biosensors allow direct detection of interaction patterns without the need for labeling. An overview covering several commercially available biosensors is given, with a focus on instruments based on surface plasmon resonance (SPR) and reflectometric interference spectroscopy (RIFS). Potential assay formats and experimental design, appropriate controls, and calibration procedures, especially when handling low molecular weight substances, are discussed. The single steps of an interaction analysis combined with practical tips for evaluation, data processing, and interpretation of kinetic data are described in detail. In a practical example, a step-by-step procedure for the analysis of a low molecular weight compound interaction with serum protein, determined on a commercial SPR sensor, is presented.
authors.affiliation: Department of Biochemistry, University of Kassel, Kassel, Germany.
authors.forename: Frank
authors.initials: F
authors.lastname: Gesellchen
authors.forename: Bastian
authors.initials: B
authors.lastname: Zimmermann
authors.forename: Friedrich W
authors.initials: FW
authors.lastname: Herberg
mesh_terms: D001667:Binding, Competitive; D015374:Biosensing Techniques / Q000295:instrumentation / Q000379:methods* / Q000706:statistics & numerical data; D003627:Data Interpretation, Statistical; D006801:Humans; D066298:In Vitro Techniques; D007700:Kinetics; D008024:Ligands; D008970:Molecular Weight; D055095:Optics and Photonics / Q000295:instrumentation; D011485:Protein Binding; D012709:Serum Albumin / Q000378:metabolism; D013057:Spectrum Analysis / Q000295:instrumentation / Q000379:methods; D020349:Surface Plasmon Resonance / Q000295:instrumentation / Q000379:methods; D014859:Warfarin / Q000378:metabolism
chemical_list: D008024:Ligands; D012709:Serum Albumin; D014859:Warfarin