title: The Pleurotus ostreatus hydrophobin Vmh2 and its interaction with glucans.
abstract: Hydrophobins are small self-assembling proteins produced by fungi. A class I hydrophobin secreted by the basidiomycete fungus Pleurotus ostreatus was purified and identified. The pure protein is not water soluble, whereas complexes formed between the protein and glycans, produced in culture broth containing amylose, are soluble in water. Glycan structure matched to cyclic structures of alpha-(1-4) linked glucose containing from six to 16 monomers (cyclodextrins). Moreover, it was verified that not only pure cyclodextrins but also a linear oligosaccharide and even the simple glucose monomer are able to solubilize the hydrophobin in water. The aqueous solution of the protein-in the presence of the cyclic glucans-showed propensity to self-assembly, and conformational changes towards beta structure were observed on vortexing the solution. On the other hand, the pure protein dissolved in less polar solvent (60% ethanol) is not prone to self assembly, and no conformational change was observed. When the pure protein was deposited on a hydrophobic surface, it formed a very stable biofilm whose thickness was about 3 nm, whereas the biofilm was not detected on a hydrophilic surface. When the water-soluble protein-in the presence of the cyclic glucans-was used, thicker (up to 10-fold) biofilms were obtained on either hydrophilic or hydrophobic surfaces.
authors.affiliation: Department of Organic Chemistry and Biochemistry, University of Naples "Federico II", Via Cintia 4, 80126, Naples, Italy.
authors.forename: Annunziata
authors.initials: A
authors.lastname: Armenante
authors.forename: Sara
authors.initials: S
authors.lastname: Longobardi
authors.forename: Ilaria
authors.initials: I
authors.lastname: Rea
authors.forename: Luca
authors.initials: L
authors.lastname: De Stefano
authors.forename: Michele
authors.initials: M
authors.lastname: Giocondo
authors.forename: Alba
authors.initials: A
authors.lastname: Silipo
authors.forename: Antonio
authors.initials: A
authors.lastname: Molinaro
authors.forename: Paola
authors.initials: P
authors.lastname: Giardina
mesh_terms: D005656:Fungal Proteins / Q000737:chemistry*; D005936:Glucans / Q000737:chemistry*; D020076:Pleurotus / Q000737:chemistry*; D012995:Solubility; D014867:Water / Q000737:chemistry
chemical_list: D005656:Fungal Proteins; D005936:Glucans; D014867:Water