New clues into the self-assembly of Vmh2, a basidiomycota class i hydrophobin

Hydrophobins are fungal proteins that can selfassemble into amphiphilic films at hydrophobic-hydrophilic interfaces. Class I hydrophobin aggregates resemble amyloid fibrils, sharing some features with them. Here, five site-directed mutants of Vmh2, a member of basidiomycota class I hydrophobins, were designed and characterized to elucidate the molecular determinants playing a key role in class I hydrophobin self-assembly. The mechanism of fibril formation proposed for Vmh2 foresees that the triggering event is the destabilization of a specific loop (L1), leading to the formation of a β-hairpin, which in turn generates the β-spine of the amyloid fibril.