Heterologous expression, kinetic characterization and molecular modeling of a new sn-1, 3-regioselective triacylglycerol lipase from Serratia sp. W3. (April 2021)

• Record Type: Journal Article
• Authors: Eddehech, Ahlem; Rahier, Renaud; Smichi, Nabil; Arhab, Yani; Noiriel, Alexandre; Abousalham, Abdelkarim; Sayari, Adel; Zarai, Zied
• Is Part Of: Process biochemistry. Volume 103(2021)
• Page Start: 87
• Page End: 97
• Publication Date: 2021-04
• Subjects: Serratia lipase expression -- Catalytic activity -- Interfacial properties -- Regio-selectivity -- Molecular modeling; Biochemical engineering -- Periodicals; Biotechnology -- Periodicals; Biochemistry -- periodicals; Biotechnology -- periodicals; Chemical Engineering -- periodicals; Génie biochimique -- Périodiques; Biotechnologie -- Périodiques; Biochemical engineering; Biotechnology; Periodicals; 660.63
• DOI: 10.1016/j.procbio.2021.02.009
• Languages: English
• ISSNs: 1359-5113

Abstract

Graphical abstract: Highlights: A lipase gene from Serratia sp. W3 (SmL) was expressed in E. coli and purified. The specific activity of the rSmL was around 12-fold than that of the native SmL. rSmL efficiently hydrolyzed triglycerides with short and medium chain fatty acids. SmL exhibited a clear regio-preference toward the sn -3 position of triglycerides. Abstract: A recombinant Serratia sp. W3 lipase (rSmL) was expressed in E. coli and purified to homogeneity. The kinetic properties, regio-selectivity, and interfacial performances of rSmL were compared with those of the native lipase (nSmL). rSmL has a molecular mass of 67 kDa and a specific activity of 3530 U mg −1 which is around 12-fold higher than that of nSmL (300 U mg −1 ) when using olive oil as the substrate. Both rSmL and nSmL were able to hydrolyze the ester bond at the sn -1 and sn -3 positions but exhibited a clear regio-preference towards the sn -3 position of the surface-coated triglycerides (TG), which were esterified with α-eleostearic acid at the sn -1/3 position or dicaprin isomers spread as monomolecular films. Molecular modeling and docking of TG into the active site of rSmL indicated that this regio-preference may be due to steric hindrance, created by the residues Ile 308 and Trp 311, with distances between the sn- 1 reactive carbon and the catalytic Serine residue ranging from 3.15 to 5.47 Å. In contrast, the sn -3 positioning within the enzyme catalytic pocket resulted in shorter distances, ranging from 2.79 to 4.15 Å, therefore facilitating the hydrolysis at the sn -3 position.