title: Modes of conformational changes of proteins adsorbed on a planar hydrophobic polymer surface reflecting their adsorption behaviors.
abstract: Infrared spectra of hen egg white lysozyme and bovine serum albumin (BSA) adsorbed on a solid poly tris(trimethylsiloxy)silylstyrene (pTSS) surface in D2O solution were measured using attenuated total reflection (ATR) Fourier transform infrared spectroscopy. From the area and shape of the amide I' band of each spectrum, the adsorption amount and the secondary structure were determined simultaneously, as a function of adsorption time. We could show that the average conformation for all the adsorbed lysozyme molecules was solely determined by the adsorption time, and independent of the bulk concentration, while the adsorption amount increased with the bulk concentration as well as the adsorption time. These results suggest that lysozyme molecules form discrete assemblies on the surface, and that the surface assemblies grow over several hours to have a definite architecture independent of the adsorption amount. As for BSA, the extent of the conformational change was solely determined by the adsorption amount, regardless of the bulk concentration and the adsorption time. These differences in the adsorption properties of lysozyme and BSA may reflect differences in their conformational stabilities.
authors.affiliation: Faculty of Engineering, Gifu University, 1-1 Yanagido, Gifu 501-1193, Japan. ishiguro@biomol.gifu-u.ac.jp
authors.forename: Ryo
authors.initials: R
authors.lastname: Ishiguro
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Yokoyama
authors.forename: Hirotaka
authors.initials: H
authors.lastname: Maeda
authors.forename: Aya
authors.initials: A
authors.lastname: Shimamura
authors.forename: Keiichi
authors.initials: K
authors.lastname: Kameyama
authors.forename: Koichi
authors.initials: K
authors.lastname: Hiramatsu
mesh_terms: D000327:Adsorption; D000818:Animals; D002417:Cattle; D002645:Chickens; D057927:Hydrophobic and Hydrophilic Interactions; D015394:Molecular Structure; D009113:Muramidase / Q000737:chemistry*; D017646:Organosilicon Compounds / Q000737:chemistry*; D011108:Polymers / Q000737:chemistry*; D011487:Protein Conformation; D012710:Serum Albumin, Bovine / Q000737:chemistry*; D013499:Surface Properties; D013997:Time Factors
chemical_list: D017646:Organosilicon Compounds; D011108:Polymers; C514558:tris(trimethylsiloxy)silylstyrene homopolymer; D012710:Serum Albumin, Bovine; C421864:hen egg lysozyme; D009113:Muramidase