Optical Control of Enzyme Enantioselectivity in Solid Phase
作者:Antoni Bautista-Barrufet、Fernando López-Gallego、Víctor Rojas-Cervellera、Carme Rovira、Miquel A. Pericàs、José M. Guisán、Pau Gorostiza
DOI:10.1021/cs401115s
日期:2014.3.7
engineered to specifically anchor photochromic molecules into its catalytic site. Several combinations of azobenzene and spiropyran groups were conjugated to cysteines introduced at different positions near the active center. Light modulated the catalytic properties of the resulting solid bioconjugates, and such modulation depended on both the nature of the photochromic compound and the anchoring position
Purification and improvement of the functional properties of Rhizopus oryzae lipase using immobilization techniques
作者:N. Ghattas、M. Filice、F. Abidi、J.M. Guisan、A. Ben Salah
DOI:10.1016/j.molcatb.2014.09.012
日期:2014.12
The adsorption/immobilization of Rhizopus oryzae lipase (ROL) has permitted the development of several strategies to improve the properties of this industrial enzyme. The enzyme can be purified, immobilized, hyperactivated and stabilized, though its enantioselectivity could still be improved. A moderately hydrophobic support (e.g., phenyl-Toyopearl) allows the almost-quantitative immobilization of the enzyme via selective hydrophobic adsorption, while any contaminant proteins are not adsorbed. A further desorption of the adsorbed enzyme with surfactants (e.g., 0.5% sucrose laurate) allows the complete purification of the enzyme in only one step, with a 90% purification yield and an 8-fold purification factor. By using a more hydrophobic support, the ROL can be immobilized and hyperactivated. The enzyme is completely adsorbed on octyl-Sepharose and C18-Sepabeads. The pure enzyme (when adsorbed on these supports) becomes hyperactivated to approximately 250% of the activity of the soluble enzyme. In this study, two protocols for the covalent immobilization of ROL were developed: a one-point immobilization on CNBr-activated Sepharose and a multipoint covalent immobilization on highly activated glyoxyl-agarose supports. The multipoint attached enzyme decreased in activity to 50% of the activity of the soluble enzyme, but the derivatives were 300-fold more stable than the soluble enzyme. The hydrolysis of racemic 2-O-butyryl-2-phenylacetic acid was modulated by the different immobilized derivatives. In fact, the most active and selective preparation was demonstrated to be the C18-SB-ROL derivative (0.05 UI/mg and E = 22) when compared with the CNBr-ROL enzyme preparation (0.0073 UI/mg and E = 3.5). (C) 2014 Elsevier B.V. All rights reserved.
Modulation of Immobilized Lipase Enantioselectivityvia Chemical Amination
作者:Jose M. Palomo、Gloria Fernández-Lorente、Jose M. Guisán、Roberto Fernández-Lafuente
DOI:10.1002/adsc.200600555
日期:2007.5.7
chemical modification while in other cases the activity was strongly reduced. Moreover, the effect of the experimental conditions on the activity was also strongly altered. Remarkably, the enantioselectivity of the enzymes in the hydrolysis of different mandelic acid derivatives was strongly modulated. For example, amination of the CNBr-CAL-B preparation greatly increased the enantioselectivity of the