Novel Carriers for Enzyme Immobilization
|N.Miletic at rug.nl|
Enzymes have been optimized, via natural evolution, to fulfill their biological function: to catalyze reactions in complex metabolic pathways exposed to many levels of regulation. Therefore, natural enzymes seldom have the features adequate to be used as industrial catalysts in organic synthesis. The operational conditions of chemical processes are far from the environment in which the enzyme flourished in nature. Enzymes can denature due to solvent effects and mechanical shear. Recovery of enzymes from reaction solutions and separation of the enzymes from substrates and products are generally difficult. The productivity (space, time, yield) of enzymatic processes is often low due to substrate and/or product inhibition.
An important route to improving enzyme performance in non-natural environments is to immobilize them by either adsorption, covalent attachment or by incorporation in hydrophobic organic-inorganic hybrid materials with the help of a sol-gel process. These immobilization procedures have resulted in remarkable improvements in performance: increased enzyme activity (up to a factor of 100) in organic solvents; increased enantioselectivity; remarkable long-term stability; increased temperature stability and convenient recovery by filtration or centrifugation. Increased stability is due to the fact that enzyme activity changes as a function of its local environment (e.g. solvent polarity, surface chemistry). However, it is important to move beyond general correlations to a better understanding on a molecular level of how immobilization on surfaces can stabilize and activate protein catalysts. Our research is directed towards the rapid identification of surface chemistries/morphologies that when in contact with proteins leads to improvements in enzyme activity and stability.
|Last modified:||01 July 2015 10.53 a.m.|