Lipases : Structure, Functions and Role in Health and Disease

In this collection, the authors discuss endothelial lipase (EL), a recently identified member of the lipase gene family which exhibits a high degree of sequence similarity to lipoprotein lipase and hepatic lipase. The opening chapter summarizes the recent findings with regard to the molecular structure and biological mechanisms of EL, factors affecting the EL expression and activity as well as its role in some inflammatory disorders. Additionally, enzyme lipase is discussed; specifically its wide range of applications in the food, cosmetic, pharmaceutical as well as oleochemical industries. The capability of enzyme lipase to catalyse reactions with higher efficiency and stability, their chemo-, regio- and enantioselectivity properties, as well as their eco-friendly characteristics resulted in their high demand worldwide. Following this, the use of enzyme immobilization as an efficient strategy to overcome certain drawbacks is analyzed. Immobilization of lipases enhances properties such as thermostability and activity, facilitates separation of products, and provides more flexibility with enzyme/substrate contact by using various reactor configurations. This chapter will also highlight benefits of immobilization in lipase stabilization with respect to other employed methods such as chemical modification and recombinant DNA technology. In the concluding study, three commercially available lipases, namely Lipase PS-CI and Lipase PS-DI from Pseudomonas cepacia (non-specific lipase), and Lipozyme RM-IM from Rhizomucor miehei (1,3-regioselective lipase) were screened for their effect on catalyzing the acidolysis of tricaprylin with ALA. The effect of substrate molar ratio, temperature and time of reaction on incorporation of ALA were investigated and optimized by response surface methodology. The study reveals the potential of lipase-catalyzed acidolysis of palm oil with ALA as a suitable alternative to improve the nutritional properties and health-beneficial effects of edible oils.