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Michael-type additions of various thiols and alpha,beta-unsaturated carbonyl compounds were performed in organic solvent catalyzed by wild-type and a rationally redesigned mutant of Candida antarctica lipase B. The mutant lacks the nucleophilic serine 105 in the active-site; this results in a changed catalytic mechanism of the enzyme. The possibility of(More)
The binding of zinc (Zn) ions to proteins is important for many cellular events. The theoretical and computational description of this binding (as well as that of other transition metals) is a challenging task. In this paper the binding of the Zn ion to four cysteine residues in the structural site of horse liver alcohol dehydrogenase (HLADH) is studied(More)
Enzymes are efficient catalysts in synthetic chemistry, and their catalytic activity with unnatural substrates in organic reaction media is an area attracting much attention. Protein engineering has opened the possibility to change the reaction specificity of enzymes and allow for new reactions to take place in their active sites. We have used this strategy(More)
A series of organic chromophores have been synthesized in order to approach optimal energy level composition in the TiO2-dye-iodide/triiodide system in the dye-sensitized solar cells. HOMO and LUMO energy level tuning is achieved by varying the conjugation between the triphenylamine donor and the cyanoacetic acid acceptor. This is supported by spectral and(More)
The mechanism of a base-catalyzed one-pot reaction of 2-cyanobenzaldehyde and primary nitroalkanes, to produce 3-substituted isoindolinones, has been investigated. A route starting with a nitroaldol (Henry) reaction, followed by a subsequent cyclization and rearrangement, was supported by intermediate analogue synthesis and DFT calculations. Direct(More)
Molecular dynamics (MD) simulations have been performed on the regulatory domain of the Escherichia coli OxyR transcription factor for the different chemical states along the mechanistic cycle for its activation by hydrogen peroxide. Conformational analysis indicates that His198 and Arg220 catalytic residues can be involved in the biochemical process of(More)
Three new sensitizers for photoelectrochemical solar cells were synthesized consisting of a triphenylamine donor, a rhodanine-3-acetic acid acceptor and a polyene connection. The conjugation length was systematically increased, which resulted in two effects: first, it led to a red-shift of the optical absorption of the dyes, resulting in an improved(More)
We describe a procedure for performing quantitative analyses of fields f(r) on molecular surfaces, including statistical quantities and locating and evaluating their local extrema. Our approach avoids the need for explicit mathematical representation of the surface and can be implemented easily in existing graphical software, as it is based on the very(More)
The mechanism and potential energy surface for the Baeyer-Villiger oxidation of acetone with hydrogen peroxide catalyzed by a Ser105-Ala mutant of Candida antarctica Lipase B has been determined using ab initio and density functional theories. Initial substrate binding has been studied using an automated docking procedure and molecular dynamics simulations.(More)