title: Study of receptor-chaperone interactions using the optical technique of spectroscopic ellipsometry.
abstract: This work describes a detailed quantitative interaction study between the novel plastidial chaperone receptor OEP61 and isoforms of the chaperone types Hsp70 and Hsp90 using the optical method of total internal reflection ellipsometry (TIRE). The receptor OEP61 was electrostatically immobilized on a gold surface via an intermediate layer of polycations. The TIRE measurements allowed the evaluation of thickness changes in the adsorbed molecular layers as a result of chaperone binding to receptor proteins. Hsp70 chaperone isoforms but not Hsp90 were shown to be capable of binding OEP61. Dynamic TIRE measurements were carried out to evaluate the affinity constants of the above reactions and resulted in clear discrimination between specific and nonspecific binding of chaperones as well as differences in binding properties between the highly similar Hsp70 isoforms.
authors.affiliation: Biomedical Research Centre, Sheffield Hallam University, Sheffield, United Kingdom. v.kriechbaumer@shu.ac.uk
authors.forename: Verena
authors.initials: V
authors.lastname: Kriechbaumer
authors.forename: Anna
authors.initials: A
authors.lastname: Tsargorodskaya
authors.forename: Mohd K
authors.initials: MK
authors.lastname: Mustafa
authors.forename: Tatiana
authors.initials: T
authors.lastname: Vinogradova
authors.forename: Joanne
authors.initials: J
authors.lastname: Lacey
authors.forename: David P
authors.initials: DP
authors.lastname: Smith
authors.forename: Benjamin M
authors.initials: BM
authors.lastname: Abell
authors.forename: Alexei
authors.initials: A
authors.lastname: Nabok
mesh_terms: D000818:Animals; D017360:Arabidopsis / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000378:metabolism*; D002138:Calibration; D018840:HSP70 Heat-Shock Proteins / Q000378:metabolism*; D018841:HSP90 Heat-Shock Proteins / Q000378:metabolism*; D007700:Kinetics; D008954:Models, Biological; D018832:Molecular Chaperones / Q000378:metabolism*; D055095:Optics and Photonics / Q000379:methods*; D011485:Protein Binding; D021381:Protein Transport; D011817:Rabbits; D011956:Receptors, Cell Surface / Q000378:metabolism*; D013057:Spectrum Analysis / Q000379:methods*
chemical_list: D029681:Arabidopsis Proteins; D018840:HSP70 Heat-Shock Proteins; D018841:HSP90 Heat-Shock Proteins; D018832:Molecular Chaperones; C561502:OEP61 protein, Arabidopsis; D011956:Receptors, Cell Surface