title: Tuning protein GlnB-Hs surface interaction with silicon: FTIR-ATR, AFM and XPS study.
abstract: Herbaspirillum seropedicae GlnB (GlnB-Hs) is a signal transduction protein involved in the control of nitrogen, carbon and energetic metabolism. The adsorption of GlnB-Hs deposited by spin coating on hydrophilic and hydrophobic silicon forms a thin layer that was characterized using atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared attenuated total reflectance spectroscopy (FTIR-ATR). AFM allowed the identification of globular, face-up donut like array of protein on hydrophilic silicon substrate, favoring deprotonated residues to contact the silicon oxide surface. Over hydrophobic silicon, GlnB-Hs adopts a side-on conformation forming a filament network, avoiding the contact of protonated residues with silicon surface. XPS allowed us to determine the protonated and non-protonated states of nitrogen 1s (N 1s). The FTIR-ATR measurements provided information about protein secondary structure and its conservation, after surface adsorption.
authors.affiliation: Departamento de Física, Universidade Federal do Paraná (UFPR), Jd. das Américas - Centro Politécnico, Caixa Postal 19044, Curitiba CEP 81.531-990, PR, Brazil. af.lubambo@uol.com.br
authors.forename: A F
authors.initials: AF
authors.lastname: Lubambo
authors.forename: E M
authors.initials: EM
authors.lastname: Benelli
authors.forename: J J
authors.initials: JJ
authors.lastname: Klein
authors.forename: W H
authors.initials: WH
authors.lastname: Schreiner
authors.forename: E
authors.initials: E
authors.lastname: Silveira
authors.forename: P C
authors.initials: PC
authors.lastname: de Camargo
mesh_terms: D001426:Bacterial Proteins / Q000737:chemistry* / Q000378:metabolism*; D042803:Herbaspirillum / Q000378:metabolism; D057927:Hydrophobic and Hydrophilic Interactions; D018625:Microscopy, Atomic Force / Q000379:methods*; D056951:Photoelectron Spectroscopy / Q000379:methods*; D011485:Protein Binding; D017433:Protein Structure, Secondary; D012825:Silicon / Q000737:chemistry*; D017550:Spectroscopy, Fourier Transform Infrared / Q000379:methods*; D055672:Static Electricity
chemical_list: D001426:Bacterial Proteins; D012825:Silicon