Hevea brasiliensis prohevein possesses a conserved C-terminal domain with amyloid-like properties in vitro.

Prohevein is a wound-induced protein and a main allergen from latex of Hevea brasiliensis (rubber tree). This 187 amino-acid protein is cleaved in two fragments: a N-terminal 43 amino-acids called hevein， a lectin bearing a chitin-binding motif with antifungal properties and a C-terminal domain (C-ter) far less characterized. We provide here new insights on the characteristics of prohevein， hevein and C-terminal domain. Using complementary biochemical (ThT/CR/chitin binding， agglutination) and structural (modeling， ATR-FTIR， TEM， WAXS) approaches， we show that this domain clearly displays all the characteristics of an amyloid-like proteins in vitro， that could confer agglutination activity in synergy with its chitin-binding activity. Additionally， this C-ter domain is highly conserved and present in numerous plant prohevein-like proteins or pathogenesis-related (PR and WIN) proteins. This could be the hallmark of the eventual presence of proteins with amyloid properties in plants， that could potentially play a role in defense through aggregation properties.