title: Detection of protein-protein interactions on SiO2/Si surfaces by spectroscopic ellipsometry.
abstract: We have applied spectroscopic ellipsometry to sensitive detection of specific protein-protein interactions on SiO2/Si substrates. First, the change of ellipticity of the reflected polarized light (600-1100 nm) was correlated with the thickness of the protein layer immobilized on SiO2/Si surfaces by measuring monomeric (myoglobin) and homotetrameric (hemoglobin) proteins with a similar monomer size. Protein-protein interactions were then measured with the antigen/antibody and cell-surface receptor/ligand systems; in each system either of the two proteins was bound to SiO2/Si substrates. Consequently, significant ellipticity changes were observed only for the cases where the interactions were specific. A specific antibody binding was also detectable with an antigen displayed on the surface of bacteriophage particles. These results show the usefulness of spectroscopic ellipsometry for sensitive detection of protein-protein interactions and its applicability to a detection method for the protein-based biochips to be developed in the future.
authors.affiliation: The Institute of Scientific and Industrial Research, Osaka University, Ibaraki, Osaka 567-0047, Japan.
authors.forename: Seigo
authors.initials: S
authors.lastname: Kodera
authors.forename: Toshihide
authors.initials: T
authors.lastname: Okajima
authors.forename: Hidehiko
authors.initials: H
authors.lastname: Iwabuki
authors.forename: Daisuke
authors.initials: D
authors.lastname: Kitaguchi
authors.forename: Shun'ichi
authors.initials: S
authors.lastname: Kuroda
authors.forename: Tatsuo
authors.initials: T
authors.lastname: Yoshinobu
authors.forename: Katsuyuki
authors.initials: K
authors.lastname: Tanizawa
authors.forename: Masamitsu
authors.initials: M
authors.lastname: Futai
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Iwasaki
mesh_terms: D000818:Animals; D000906:Antibodies / Q000276:immunology; D000918:Antibody Specificity; D000941:Antigens / Q000032:analysis / Q000276:immunology; D017104:Bacteriophage M13 / Q000235:genetics; D004815:Epidermal Growth Factor / Q000378:metabolism; D066246:ErbB Receptors / Q000032:analysis / Q000378:metabolism; D006454:Hemoglobins / Q000032:analysis / Q000378:metabolism; D006801:Humans; D007259:Infrared Rays; D008024:Ligands; D051379:Mice; D009211:Myoglobin / Q000032:analysis / Q000378:metabolism; D011485:Protein Binding; D011506:Proteins / Q000032:analysis / Q000378:metabolism*; D011817:Rabbits; D011993:Recombinant Fusion Proteins / Q000032:analysis / Q000378:metabolism; D012825:Silicon / Q000737:chemistry*; D012822:Silicon Dioxide / Q000737:chemistry*; D013057:Spectrum Analysis / Q000295:instrumentation* / Q000379:methods*
chemical_list: D000906:Antibodies; D000941:Antigens; D006454:Hemoglobins; D008024:Ligands; D009211:Myoglobin; D011506:Proteins; D011993:Recombinant Fusion Proteins; D004815:Epidermal Growth Factor; D012822:Silicon Dioxide; D066246:ErbB Receptors; D012825:Silicon