Hydrolysis of fish oil by hyperactivated rhizomucor miehei lipase immobilized by multipoint anion exchange |
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Authors: | Marco Filice Marzia Marciello Lorena Betancor Alfonso V. Carrascosa Jose M. Guisan Gloria Fernandez‐Lorente |
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Affiliation: | 1. Dept. of Biocatalysis, Instituto de Catálisis, CSIC, Campus UAM, Cantoblanco, 28049 Madrid, Spain;2. Dept. of Microbiology, Madrid Institute for Advanced Studies, Campus UAM, Cantoblanco, Pabellón C, Madrid, Spain;3. Instituto de Fermentaciones Industriales, CSIC, 2006 CSIC, Madrid, Spain |
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Abstract: | Rhizomucor miehei lipase (RML) is greatly hyperactivated (around 20‐ to 25‐fold toward small substrates) in the presence of sucrose laurate. Hyperactivation appears to be an intramolecular process because it is very similar for soluble enzymes and covalently immobilized derivatives. The hyperactivated enzyme was immobilized (in the presence of sucrose laurate) on cyanogen bromide‐activated Sepharose (very mild covalent immobilization through the amino terminal residue), on glyoxyl Sepharose (intense multipoint covalent immobilization through the region with the highest amount of Lys residues), and on different anion exchangers (by multipoint anionic exchange through the region with the highest density of negative charges). Covalent immobilization does not promote the fixation of the hyperactivated enzyme, but immobilization on Sepharose Q retains the hyperactivated enzyme even in the absence of a detergent. The hydrolysis of fish oils by these hyperactivated enzyme derivatives was sevenfold faster than by covalently immobilized derivatives and three and a half times faster than by the enzyme hyperactivated on octyl‐Sepharose. The open structure of the hyperactivated lipase is fairly exposed to the medium, and no steric hindrance should interfere with the hydrolysis of large substrates. These new hyperactivated derivatives seem to be more suitable for hydrolysis of oils by RML immobilized inside porous supports. In addition, the hyperactivated derivatives are fairly stable against heat and organic cosolvents. © 2011 American Institute of Chemical Engineers Biotechnol. Prog., 2011 |
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Keywords: | lipase hyperactivation fixation of hyperactivated lipases multipoint interaction with activated supports |
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