Functional charachterization of the βγ-crystallin domain of a phosphatidylinositol phospholipase C from Lysinobacillus sphaericus

CERMINATI, SEBASTIAN; PAOLETTI, LUCIANA; PEIRÚ, SALVADOR; MENZELLA HUGO; CASTELLI, MARÍA E.

Congreso; LIV Reunión Anual de la Sociedad Argentina de Investigación Bioquímica y Biología Molecular; 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. The various members present a series of evolutionary adaptations culminating in great diversity in properties and functions. We have recently described the development of a new phosphatidylinositol phospholipase C from Lysinobacillus sphaericus (LS-PIPLC) to be used for oil degumming which was shown to efficiently remove phosphatidylinositol 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 βγ-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-PIPLC an excellent candidate for use in industrial soybean oil degumming.