bg-CRYSTALLIN DOMAIN OF Lysinibacillus sphaericus PI-PLC PLAYS A CENTRAL ROLE IN PROTEIN STABILITY

MARCHISIO, FIORELA; CASTELLI, MARÍA EUGENIA; PAOLETTI, LUCIANA; MENZELLA, HUGO G.; CERMINATI, SEBASTIÁN; VAL, DIEGO SEBASTIÁN

Paraná

Congreso; 54th Annual Meeting Argentine Society for Biochemistry and Molecular Biology; 2018

-crystallins have emerged as a superfamily of structurally homologous proteins with representatives across all the domains of life. A major portion of this superfamily is constituted by members from microorganisms. This superfamily has also been recognized as a novel group of Ca2+-binding proteins with huge diversity and variable properties in Ca2+-binding, stability and association with other domains. We have recently described the development of a new phosphatidylinositol (PI) phospholipase C from Lysinobacillus sphaericus (LS-PIPLC) to be used for oil degumming which was shown to efficiently remove PI from crude oil. Here, the role of the C-terminal  -crystallin domain of LS-PIPLC is analyzed in the context of the whole protein. A truncated protein in which the C-terminal  -crystallin domain was deleted (LS-PIPLCΔCRY) is catalytically as efficient as the full-length protein (LS-PIPLC). However, the thermal and chemical stability of LS-PIPLCΔCRY are highly affected, demonstrating a stabilizing role for this domain. It is also shown that the presence of Ca2+ increases the thermal and chemical stability of the protein both in aqueous media and in oil, making LS-PI-PLC an excellent candidate for use in industrial soybean oil degumming