title: Hydrophobin Vmh2-glucose complexes self-assemble in nanometric biofilms.
abstract: Hydrophobins are small proteins secreted by fungi, which self-assemble into amphipathic membranes at air-liquid or liquid-solid interfaces. The physical and chemical properties of some hydrophobins, both in solution and as a biofilm, are affected by poly or oligosaccharides. We have studied the interaction between glucose and the hydrophobin Vmh2 from Pleurotus ostreatus by spectroscopic ellipsometry (SE), atomic force microscopy (AFM) and water contact angle (WCA). We have found that Vmh2-glucose complexes forms a chemically stable biofilm, obtained by drop deposition on silicon, 1.6 nm thick and containing 35 per cent of glucose, quantified by SE. AFM highlighted the presence of nanometric rodlet-like aggregates (average height, width and length being equal to 3.6, 23.8 and 40 nm, respectively) on the biofilm surface, slightly different from those obtained in the absence of glucose (4.11, 23.9 and 64 nm). The wettability of a silicon surface, covered by the organic layer of Vmh2-glucose, strongly changed: WCA decreased from 90° down to 17°.
authors.affiliation: Unit of Naples, Institute for Microelectronics and Microsystems, National Council of Research, Via Pietro Castellino 111, 80131 Naples, Italy. ilaria.rea@na.imm.cnr.it
authors.forename: Ilaria
authors.initials: I
authors.lastname: Rea
authors.forename: Paola
authors.initials: P
authors.lastname: Giardina
authors.forename: Sara
authors.initials: S
authors.lastname: Longobardi
authors.forename: Fabrizio
authors.initials: F
authors.lastname: Porro
authors.forename: Valeria
authors.initials: V
authors.lastname: Casuscelli
authors.forename: Ivo
authors.initials: I
authors.lastname: Rendina
authors.forename: Luca
authors.initials: L
authors.lastname: De Stefano
mesh_terms: D001672:Biocompatible Materials / Q000737:chemistry*; D018441:Biofilms / Q000254:growth & development*; D005656:Fungal Proteins / Q000737:chemistry*; D005947:Glucose / Q000737:chemistry*; D018625:Microscopy, Atomic Force; D049329:Nanostructures / Q000737:chemistry; D036103:Nanotechnology; D020076:Pleurotus / Q000737:chemistry* / Q000502:physiology*; D013056:Spectrophotometry, Ultraviolet
chemical_list: D001672:Biocompatible Materials; D005656:Fungal Proteins; D005947:Glucose