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

Abstract

βγ-crystallin has emerged as a superfamily of structurally homologous proteins with representatives across all 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 Ca-binding proteins with a large diversity and variable properties in Ca binding and stability. We have recently described a new phosphatidylinositol phospholipase C from Lysinibacillus sphaericus (LS-PIPLC) which was shown to efficiently remove phosphatidylinositol from crude vegetable oil. Here, the role of the C-terminal βγ-crystallin domain of LS-PIPLC was analyzed in the context of the whole protein. A truncated protein in which the C-terminal βγ-crystallin domain was deleted (LS-PIPLC) is catalytically as efficient as the full-length protein (LS-PIPLC). However, the thermal and chemical stability of LS-PIPLC are highly affected, demonstrating a stabilizing role for this domain. It is also shown that the presence of Ca 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.

βγ-Crystallination Endows a Novel Bacterial Glycoside Hydrolase 64 with Ca2+-Dependent Activity Modulation

“…Our study demonstrates that the ancillary domains increase the stability as well as the activity of glucanallin in Ca 2ϩ -dependent manner. On the other hand, in phosphatidylinositol phospholipase C from Lysinibacillus sphaericus, the ␤␥-crystallin domain increases the enzyme stability but not the activity (41). The role of such associations yet needs to be understood completely and should be explored in the biological context.…”

Sustainable Refining of Vegetable Oil Made Easy with a Designer Phospholipase C Enzyme

“…However, the use of PLCbased technologies is far from being widely adopted because of its cost. 9 Traditional water degumming is performed in 30 min at 75− 80 °C. 10 When enzymes are employed, these harsh conditions need to be softened because commercial PLCs available today work at 55 °C and need 2 h or more to process the substrates, requiring the insertion of heat exchangers and larger reactors in the refining plants 11,12 (Figure 1).…”

“…Vegetable oils represent a core sector of the global economy, and their demand for food and fuel production is continuously increasing (Cerminati et al, 2017(Cerminati et al, , 2018Elena et al, 2016Elena et al, , 2017. Even when they are renewable, the environmental impact of deforestation to produce them and the emissions and waste generated during oil extraction and re ning make the production unsustainable (Hails et al, 2020;Aguirre et.…”

“…Microbial PLCs with dual specificity for PC and PE (PC-PLCs) are the most effective enzymes since together they account for 70% or more of the total PLs present in oils and fats. However, the use of PLC-based technologies is far from being widely adopted because of its cost …”

Sustainable refining of vegetable oil made easy with a designer phospholipase C enzyme

“…Vegetable oils represent a major sector of the global economy and the demand of these commodities for food, and fuel production is continuously increasing (Cerminati et al, 2017(Cerminati et al, , 2018Elena et al, 2016Elena et al, , 2017. Even when they are renewable, the environmental impact of deforestation to produce them and the emission and waste generated during oil extraction and re ning makes the production unsustainable (Hails et al, 2020;Aguirre et.…”