Lipase regiospecificity

Regiospecific Reaction Catalyzed by Immobilized C. antarctica Lipase Irimescu et al. (2001, 2002) recently established a reaction system ... 

Irimescu, R., Furihata, K., Hata, K., Iwasaki, Y., and Yamane, T. 2001. Utilization of reaction medium-dependent regiospecificity of Candida antarctica lipase (Novozym 435) for the synthesis of l,3-dicapryloyl-2-docosahexaenoyl (or eicosapentaenoyl) glycerol. J. Am. Oil Chem. Soc., 78, 285-289. 

Shen, Z. and Wijesundera, C. 2006. Evaluation of ethanolysis with immobilized Candida antarctica lipase for regiospecific analysis of triacylglycerols containing highly unsaturated fatty acids. /. Am. Oil Chem. Soc., 83, 923-927. 

Shimada, Y., Ogawa, J., Watanabe, Y., Nagao, T., Kawashima, A., Kobayashi, T., and Shimizu, S. 2003b. Regiospecific analysis by ethanolysis of oil with immobilized Candida antarctica lipase. Lipids, 38,1281-1286. 

Lipase. Interesterification of triacylglycerols in the presence of a regiospecific lipase or a nonspecific lipase and free fatty acids can be used to modify the physical or nutritional characteristics of fats. Lipases from Aspergillus sp. (47,48) and Rhizopus... 

Specificity of lipases may be expressed in a number of different ways—substrate specific, regiospecific, nonspecific, fatty acyl specific, and stereospecific. Examples of these specificities have been presented by Villeneuve and Foglia (1997) (Table 10-6). 

In a related investigation, the native lipase of C. rugosa has also been used successfully for enantioselective and regiospecific transformation of butyl 2,4-dithioacetyl butyrate 177 to (i )-2,4-dithioacetyl butyric acid (i )-178 and butyl (3 )-2-thio-4-thioacetyl butyrate (d )-178 with high enantiomeric purity (>98% ee) (Scheme 25) <1998TA4109>, which were subsequently utilized for the preparation of (K)- and (J)-lipoic acids 3, respectively. 

Specificity is one of the most striking properties of enzyme molecules. Enzyme specificity can be defined as a comparative difference in rates of catalysis of certain reactions. After an enzyme is identified as a hpase, several specificities within the class are identified or can be expected to occur. The main advantage of lipases, which differentiate enzymatic reactions from chemically-catalyzed reactions, is lipase specificity. Lipases have turned out to be very useful enzymes for catalyzing various types of reactions with a rather wide substrate specificity. The fatty acid specificity of lipases has been exploited to produce structured lipids and to enrich lipids with specific fatty acids to improve the nutritional characteristics of lipids (24). Certain lipases display positional specificity (regiospecificity) toward fatty acyl groups in a TAG molecule as well as fatty acid selectivity. 

Lipases can be categorized into three groups based on their specificity random (nonregiospecific), in-1,3-specific (regiospecific) toward TAGs, or specific for a particular fatty acid or, more generally, a class of fatty acids (Figure 10). Examples... 

Key Words Bonnd water esterification ethanolysis glycerolysis immobilized glycerol lipase monoacylglycerol regiospecific analysis. 

Production of MAGs reported so far was reviewed based on the reactions (hydrolysis, esterification, and transesterification) catalyzed by lipases from the viewpoint of industrial production. In addition, application of the reactions to oil processing and regiospecific analysis of TAGs has been introduced. There is increased attention to lipases in the food industries and in the field of synthesis and degradation of unstable oil- and fat-related compounds. We hope this review is useful for those who intend to use lipases for oil and fat processing. 

There is considerable current interest in the use of microemulsions as media for lipase-catalyzed stereo- and regiospecific ester synthesis. In some cases lipases seem to display a higher degree of regioselectivity in microemulsions than in aqueous solution. 

Caballero V, Bautista FM, Campelo JM, Luna D, Marinas JM, Romero AA, Hidalgo JM, Luque R, Macario A, Giordano G (2009) Sustainable preparation of a novel glycerol-fiee biofuel by using pig pancreatic lipase partial 1,3-regiospecific alcoholysis of sunflower oiL Process Biochem 44 334-342... 

Typically, enzyme active sites consist of 3 to 12 amino acid residues structured into specific three-dimensional arrangements, as shown in Figure 1.3 for the Candida rugosa enzyme. These active sites have a strong attraction to substrates, where amino acid residues complement certain groups on the substrates. Regiospecificity and stereospecificity are other important characteristics of enzymes, where they are not only specific or selective for certain substrates but also discriminate between similar parts of molecules or optical isomers. For examples, some enzymes, like lipase, can differentiate between stereoisomers that have the same structure but a... 

Caballero, V., F. M. Bautista, J. M. Campelo, D. Luna, J. M. Marinas, A. A. Romero, J. M. Hidalgo, R. Luque, A. Macario, and G. Giordano. 2009. Sustainable Preparation of a Novel Glycerol-Free Biofuel by Using Pig Pancreatic Lipase Partial 1,3-Regiospecific Alcoholysis of Sunflower Oil. Process Biochemistry 44 (3) 334-342. 

Lipase source Specificity to acyl length Regiospecificity (sn) Lipase source Specificity to acyl length Regiospecificity (sn)... 

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