Heterogeneous catalysts have been synthesi zed by the conjugation of Hoveyda-Grubbs second-generation catalyst with a lipase. The catalytic properties of the organometallic compound in solution were firstly optimized, evaluating the activity of Ru in the ring-closing metathesis of diethyldiallymalonate at 25 °C at different solvents and in the presence of different additives. The best result wa...

-Feeding continuously operated stirred tank rectors with reactants and homogeneous catalysts subject to inactivation will usually lead to a limited substrate conversion with increasing space time. However, it is shown that a maximum of conversion may be observed under certain circumstances. Guided by experimental evidence, the theoretical background is discussed for identifying reaction systems...

The secondary alcohol dehydrogenase from Thermoanaerobacter ethanolicus 39E (TeSADH) is highly thermostable and solvent-stable, and it is active on a broad range of substrates. These properties make TeSADH an excellent template to engineer an industrial catalyst for chiral chemical synthesis. (S)-1-Phenyl-2-propanol was our target product because it is a precursor to major pharmaceuticals conta...

Fluoroacetate dehalogenase (EC 3.8.1.3) catalyzes the dehalogenation of fluoroacetate and other haloacetates. The amino acid sequence of fluoroacetate dehalogenase from Moraxella sp. B is similar to that of haloalkane dehalogenase (EC 3.8.1.5) from Xanthobacter autotrophicus GJ10 in the regions around Asp-105 and His-272, which correspond to the active site nucleophile Asp-124 and the base cata...

The ability to query enzyme molecules individually is transforming our view of catalytic mechanisms. Quiescin sulfhydryl oxidase (QSOX) is a multidomain catalyst of disulfide-bond formation that relays electrons from substrate cysteines through two redox-active sites to molecular oxygen. The chemical steps in electron transfer have been delineated, but the conformational changes accompanying th...

In a study of the mechanism of action of notatin, the flavin adenine dinucleotide-dependent glucose aerodehydrogenase of molds, Bentley and Neuberger (2) in 1949 obtained evidence suggesting that the enzyme preparation also catalyzed the mutarotation of glucose. Keilin and Hartree (3, 4) demonstrated that some notatin samples contained a second enzyme, named mutarotase, which was the most activ...

In a study of the mechanism of action of notatin, the flavin adenine dinucleotide-dependent glucose aerodehydrogenase of molds, Bentley and Neuberger (2) in 1949 obtained evidence suggesting that the enzyme preparation also catalyzed the mutarotation of glucose. Keilin and Hartree (3, 4) demonstrated that some notatin samples contained a second enzyme, named mutarotase, which was the most activ...

Assumptions of individual rationality and preference stability provide the foundation for a convenient and tractable modeling approach. While both of these assumptions have come under scrutiny in distinct literatures, the two lines of research remain disjointed. This study begins by explicitly linking the two literatures while providing insights into perhaps the central issue facing behavioral ...

Computers can be very helpful to us by performing tasks on our behalf. For example, they are very good at performing calculations, storing information and producing visualisations of objects that do not yet exist as a made artifact. Increasingly, however, a different role is being found for the computer. It is the role of a catalyst, or a stimulant, to our own creative thinking. In such cases t...

Most natural gas sources remain untapped as energy and chemical feedstocks. A catalyst for the selective oxidation of gaseous alkanes into more easily transported alcohols could allow these reserves to be exploited. Although catalytic alkane hydroxylation has been reported by many groups, selective conversion of ethane and methane mainly to their corresponding alcohols has yet to be demonstrate...