Rebuilding the lid region from conformational and dynamic features to engineering applications of lipase in foods: Current status and future prospects

Abstract

The applications of lipases in esterification, amidation, and transesterification have broadened their potential in the production of fine compounds with high cumulative values. Mostly, the catalytic triad of lipases is covered by either one or two mobile peptides called the “lid” that control the substrate channel to the catalytic center. The lid holds unique conformational allostery via interfacial activation to regulate the dynamics and catalytic functions of lipases, thereby highlighting its importance in redesigning these enzymes for industrial applications. The structural characteristic of lipase, the dynamics of lids, and the roles of lid in lipase catalysis were summarized, providing opportunities for rebuilding lid region by biotechniques (e.g., metagenomic technology and protein engineering) and enzyme immobilization. The review focused on the advantages and disadvantages of strategies rebuilding the lid region. The main shortcomings of biotechnologies on lid rebuilding were discussed such as negative effects on lipase (e.g., a decrease of activity). Additionally, the main shortcomings (e.g., enzyme desorption at high temperatre) in immobilization on hydrophobic supports via interfacial action were presented. Solutions to the mentioned problems were proposed by combinations of computational design with biotechnologies, and improvements of lipase immobilization (e.g., immobilization protocols and support design). Finally, the review provides future perspectives about designing hyperfunctional lipases as biocatalysts in the food industry based on lid conformation and dynamics.

Novel Lipase Reactor based on Discontinuous Interfaces in Hydrogel-Organogel Hybrid Gel: A Preliminary Exploration

“…Lipases (triacylglycerol ester hydrolase, EC 3.1.1.3) can catalyze many different reactions due to their broad specificity for some substrates. In addition to the hydrolysis that converts triglycerides into fatty acids and glycerol, lipases have been efficiently employed to catalyze numerous reactions, such as the synthesis of esters, amination, transesterification, interesterification, alcoholysis, acidolysis, aminolysis, and acylation. − Hence, lipases have been used in various industries, including chemicals, detergents, food, cosmetics, pharmaceuticals, paper industries, and biodiesel production. − …”

“…The active site of lipase is covered with one or two amphiphilic α-helical loops called the “lid”. ,, The hydrophobic side of “lid” faces the inner active center of lipases, while the hydrophilic side faces the outer hydrophobic substrates. , This special structure of lid is widely considered the primary local region responsible for interfacial activation phenomenon to trigger the lipases to structurally change at the hydrophilic–hydrophobic interface (water–oil interface). ,− As a harbor for free substrate, when the lipase approaches the water–oil interface, the “lid” moves from the “closed” (inactive) conformation to the “open” (active) conformation, ,− the “lid” provides an anchor for free substrate access to the catalytic center. Interfacial activation is a crucial criterion in distinguishing lipases that possess a “lid” from other types of enzymes with lids, making lipase biocatalysis with numerous potential applications.…”

“…5−12 The active site of lipase is covered with one or two amphiphilic α-helical loops called the "lid". 11,13,14 The hydrophobic side of "lid" faces the inner active center of lipases, while the hydrophilic side faces the outer hydrophobic substrates. 15,16 This special structure of lid is widely considered the primary local region responsible for interfacial activation phenomenon to trigger the lipases to structurally change at the hydrophilic−hydrophobic interface (water−oil interface).…”

Tuning Immobilized Enzyme Features by Combining Solid-Phase Physicochemical Modification and Mineralization

“…Lipases are used as model enzymes in this study, as they are among the most used enzymes at both academic and industrial levels [ 60 , 61 , 62 , 63 ]. They have a peculiar mechanism of action, called interfacial activation, as they have two possible conformations (closed and open), that in homogeneous media are in equilibrium [ 64 , 65 , 66 , 67 ]. A polypeptide called lid is able to isolate the active center in most lipases.…”

“…A polypeptide called lid is able to isolate the active center in most lipases. In the presence of any hydrophobic surface (a drop of substrate, a hydrophobic protein, but also other open form of the lipase or a hydrophobic support), the lipase becomes strongly adsorbed, with the lid shift leaving the active center exposed [ 64 , 65 , 66 , 67 ]. This has caused lipase immobilization on hydrophobic supports to become a very popular immobilization strategy, enabling the one-step immobilization, purification, stabilization and hyperactivation of the lipases [ 27 ].…”