Lipase catalytic properties

R. J. Kazlauskas, Elucidating structure-mechanism relationships in lipases prospects for predicting and engineering catalytic properties, Trends Biotechnol. 1994, 12, 464-72. 

Chapus, C. and Seremiva, M. (1976) Mechanism of pancreatic lipase action. 2. Catalytic properties of modified lipases. Biochemistry 15, 4988 4991... 

All lipases show structural and functional similarities, regardless of the organism from which they were isolated. Hence, they all have a a-(i-hydrolase fold structure with a catalytic triad. However, small variations in the substrate binding site may have a strong effect on the catalytic properties and the stability of enzyme [1]. 

Polyacrylic resins were employed to study how immobilization resin particle size influences Candida antarctica Lipase B (CALB) loading, fraction of active sites, and catalytic properties for polyester synthesis. CALB adsorbed more rapidly on smaller beads. Saturation occurred in less than 30 seconds and 48 h for beads with diameters 35 and 560-710 pm, respectively. Infrared microspectroscopy showed that CALB forms protein loading fronts for resins with particle sizes 560-710 and 120 pm while CALB appears evenly distributed throughout 35 pm resins. The fraction of active CALB molecules adsorbed onto resins not influenced by particle size was less than 50 %. At about 5% w/w CALB loading, decrease in the immobilization support diameter from 560-710 to 120,75 and 35 pm increased conversion of s-CL to polyester (20 to 36, 42 and 61%, respectively, at 80 min). Similar trends were observed for condensation polymerizations of 1,8-octanediol and adipic acid. 

Pera, L. M., Romero, C. M., Baigori, M. D., and Castro, G. R. (2006]. Catalytic properties of lipase extracts from Aspergillus niger, Food Technol Biotech., AA 2), 247-252. 

Szczesna-Antczak M, Antczak T, Rzyska M, Bielecki S (2002) Catalytic properties of membrane-bound Mucor lipase immobilized in a hydrophilic carrier. J Mol Catal B-Enzym 19-20 261-268... 

The lipase is lyophilized (most of the water is removed from around the protein) before use in such a system, to avoid a pronounced back-reaction (hydrolysis). If the enzyme shows different catalytic properties at different pH values, then these differences will be reflected in the reactions taking place in the organic solvent. The enzyme memorizes the pH of the solution from which it was lyophilized ... 

This chapter is an overview of architectures adopted for the catalytic/biocatalytic composites used in wide applications like the biomass valorization or fine chemical industry. On this perspective, the chapter updates the reader with the most fresh examples of construction designs and concepts considered for the synthesis of such composites. Their catalytic properties result from the introduction of catalytic functionalities and vary from inorganic metal species e.g., Ru, Ir, Pd, or Rh) to well-organized biochemical structures like enzymes e.g., lipase, peroxidase, (3-galactosidase) or whole cells. Catalytic/biocatalytic procedures for the biomass conversion into platform molecules e.g., glucose, GVL, Me-THF, sorbitol, succinic acid, and glycerol) and their further transformation into value-added products are detailed in order to make understandable the utility of these complex architectures and to associate the composite properties to their performances, versatility, and robustness. 

Liu Y, Chen D,YanY. Effect of ionic liquids, organic solvents and supercritical CO2 pretreatment on the conformation and catalytic properties of Candida rugosa lipase. J Mol Catal B Enzym 2013 90 123-7. 

With lipase in immobilized form, it will not be in direct contact with any external hydrophobic interface that may inactivate soluble proteins. For example, in the presence of an organic solvent the immobilized lipase may be in contact but will not be soluble, thus preventing inactivation from occurring. This was investigated by Nawani et al. (2006), who compared the catalytic properties of Bacillus sp. lipases immobilized by different techniques. In their study, stability was improved with an optimum temperature of 5°C higher than that of the soluble lipase. This was reported after immobilization by adsorption on silica and HP-20 beads followed by cross-linking with gluteraldehyde on HP-20. Montero et al. (1993) compared the stability... 

Yang, G., J. Wu, G. Xu, and L. Yang. 2009. Improvement of Catalytic Properties of Lipase from Arthrobacter Sp. By Encapsulation in Hydrophobic Sol-Gel Materials. Bioresource Technology 100 (19) 4311-4316. 

The concept of zeolite action was tested in a particular reaction where the enzyme is exposed from the beginning to an acidic environment the esterification of geraniol with acetic acid catalyzed by Candida antarctica lipase B immobilized on zeolite NaA [219]. Lipases have been used for the hydrolysis of triglycerides and due to their ambivalent hydrophobic/hydrophilic properties they are effective biocatalysts for the hydrolysis of hydrophobic substrates [220]. When water-soluble lipases are used in organic media they have to be immobilized on solid supports in order to exhibit significant catalytic activity. 

Lipase, which is highly useful for kinetic resolution, however, has a limitation for use in DKR in that it carmot be used for (S)-configuration products. For this purpose, subtiHsin, a protease from Bacillus licheniformis, can replace lipase since it provides complementary enantioselectivity (Scheme 1.4). Subtilisin, however, has been much less frequently employed in resolution compared to lipase because it displays poor catalytic performance in organic media. Subtilisin is inferior to lipase in several properties such as activity, enantioselectivity and stability. Accordingly, the use of the enzyme usually requires some special treatments for activation and stabilization before use. For example, the treatment of subtilisin with surfactants has enhanced substantially its activity and stability up to a synthetically useful level. 

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