Immobilized enzyme

About: Immobilized enzyme is a research topic. Over the lifetime, 15282 publications have been published within this topic receiving 401860 citations.

Immobilized trypsin systems coupled on-line to separation methods: recent developments and analytical applications.

Abstract: The ability to rapidly and efficiently digest and identify an unknown protein is of great utility for proteome studies. Identification of proteins via peptide mapping is generally accomplished through proteolytic digestion with enzymes such as trypsin. Limitations of this approach consist in manual sample manipulation steps and extended reaction times for proteolytic digestion. The use of immobilized trypsin for cleavage of proteins is advantageous in comparison with application of its soluble form. Enzymes can be immobilized on different supports and used in flow systems such as immobilized enzyme reactors (IMERs). This review reports applications of immobilized trypsin reactors in which the IMER has been integrated into separation systems such as reversed-phase liquid chromatography or capillary electrophoresis, prior to MS analysis. Immobilization procedures including supports, mode of integration into separation systems, and methods are described.

Optimization of reaction conditions for the production of DAG using immobilized 1,3-regiospecific lipase lipozyme RM IM

Abstract: Oils with a high DAG (1,3-DAG) content have attracted considerable attention as a healthful food oil component. In this study, we report on the synthesis of 1,3-DAG from a mixture of FA, constituted largely of oleic and linoleic acids, using an immobilized 1,3-regioselective lipase from Rhizomucor miehei in a solvent-free system. The kinetics of 1,3-DAG production from FA and glycerol were investigated on the basis of a simplified model, taking into consideration the acyl migration reaction, the removal of water, and glycerol dissolution in the oil phase in addition to the esterification reactions. Both the yield of 1,3-DAG and the purity of DAG were evaluated under a variety of experimental conditions, including reaction temperature, pressure, and amount of enzyme present. When either the reaction temperature or the amount of enzyme used was increased, the 1,3-DAG production rate increased, but yield remained relatively constant. The 1,3-DAG yield as well as the purity of DAG gradually decreased because of the enhancement of acyl migration at later stages of the reaction after the 1,3-DAG concentration reached a maximum. Vacuum was important for attaining high yields of 1,3-DAG. Under conditions of a high vacuum (1 mm Hg) at 50°C, 1.09 M 1,3-DAG was produced from 1.29 M glycerol and 2.59 MFA in an 84% yield and in 90% purity.

Chemical Modification in the Design of Immobilized Enzyme Biocatalysts: Drawbacks and Opportunities.

Abstract: Chemical modification of enzymes and immobilization used to be considered as separate ways to improve enzyme properties. This review shows how the coupled use of both tools may greatly improve the final biocatalyst performance. Chemical modification of a previously immobilized enzyme is far simpler and easier to control than the modification of the free enzyme. Moreover, if protein modification is performed to improve its immobilization (enriching the enzyme in reactive groups), the final features of the immobilized enzyme may be greatly improved. Chemical modification may be directed to improve enzyme stability, but also to improve selectivity, specificity, activity, and even cell penetrability. Coupling of immobilization and chemical modification with site-directed mutagenesis is a powerful instrument to obtain fully controlled modification. Some new ideas such as photoreceptive enzyme modifiers that change their physical properties under UV exposition are discussed.