The betagamma-Crystallin domain of Lysinibacillus sphaericus phosphatidylinositol phospholipase C plays a central role in protein stability

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

APPLIED MICROBIOLOGY AND BIOTECHNOLOGY

SPRINGER

Lugar: Berlin; Año: 2018

0175-7598

Manuscrito enviado y en revision (Feb 2018)ßγ-crystallin has 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 microbial members. This superfamily has also been recognized as a novel group of Ca²+-binding proteins with large diversity and variable properties in Ca²+- binding and stability.We have recently described a new phosphatidylinositol phospholipase C fromLysinobacillus sphaericus (LS-PIPLC) which was shown to efficiently removephosphatidylinositol from crude vegetable oil. Here, the role of the C-terminal βγ-crystallin domain of LS-PIPLC is analyzed in the context of the whole protein. A truncated protein in which the C-terminal ßγ-crystallin domain was deleted (LSPIPLCΔCRY)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 to be used in industrial soybean oil degumming.