Environmental conditions modulate the switch among different states of the hydrophobin Vmh2 from Pleurotus ostreatus

Fungal hydrophobins are amphipathic, highly surface-active and self-assembling proteins. The class I hydrophobin Vmh2 from the basidiomycete fungus Pleurotus ostreatus seems to be the most hydrophobic hydrophobin characterized so far. Structural and functional properties of the protein as a function of the environmental conditions have been determined. At least three distinct phenomena can occur, being modulated by the environmental conditions. 1- When the pH increases or in the presence of Ca2+ ions, an assembled state, -sheet rich, is formed; 2- when the solvent polarity increases the protein shows an increased tendency to reach hydrophobic/hydrophilic interfaces, with no detectable conformational change; 3- a reversible conformational change and reversible aggregation occurs at high temperature. Modulation of the Vmh2 conformational/aggregation features by changing the environmental conditions can be very useful in view of the potential protein applications.