Sialyltransferases are enzymes responsible for the important sialylation of glycoconjugates. Since crystal structures are not available, other tools are needed to study enzymatic mechanisms. As a model, we used human alpha2,6-sialyltransferase. A putative acceptor-binding domain containing the small and the very small sialyl motifs was randomly mutated. This resulted in enzymes with altered enz...

The rate of nonadiabatic long-distance electron transfer ~ET! is derived for the direct and superexchange electronic coupling between the donor and acceptor. The model takes into account a non-Condon thermal modulation of the electronic coupling through the interaction of the system transition dipoles with the polarization fluctuations of the solvent. Going from a linear donor– bridge–acceptor ...

The possibility that electrodes might serve as an electron acceptor to simulate the degradation of aromatic hydrocarbons in anaerobic contaminated sediments was investigated. Initial studies with Geobacter metallireducens demonstrated that although toluene was rapidly adsorbed onto the graphite electrodes it was rapidly oxidized to carbon dioxide with the electrode serving as the sole electron ...

We describe a new approach to making luminophores that display long emission wavelengths, long decay times, and high quantum yields. These luminophores are covalently linked pairs with a long-lifetime resonance-energy-transfer donor and a long-wavelength acceptor. The donor was a ruthenium (Ru) metal-ligand complex. The acceptor was the Texas Red. The donor and acceptor were covalently linked b...

Nanosecond absorption dynamics at approximately 685 nm after excitation of photosystem I (PS I) from Synechocystis sp. PCC 6803 is consistent with electrochromic shift of absorption bands of the Chl a pigments in the vicinity of the secondary electron acceptor A(1). Based on experimental optical data and structure-based simulations, the effective local dielectric constant has been estimated to ...

A class of tunable visible and near-infrared donor-acceptor Stenhouse adduct (DASA) photoswitches were efficiently synthesized in 2 to 4 steps from commercially available starting materials with minimal purification. Using either Meldrum's or barbituric acid "acceptors" in combination with aniline-based "donors" an absorption range spanning from 450 to 750 nm is obtained. Additionally, photoiso...

The occurrence of the iron-reducing phenomenon among some common fungi was studied. Results indicated that (i) the reduction of ferric iron to the ferrous state by fungi seems to be restricted to nitrate reductase-inducible strains such as Actinomucor repens, Alternaria tenuis, Fusarium oxysporum, and F. solani and (ii) the amount of dissolved ferrous iron may be reduced progressively by increa...

Reactive systems are real-time systems which continuously react to their environment. The Synchronie environment integrates several synchronous languages to design such systems as well as several formalisms and tools to verify their properties. The integration is based on Boolean Automata, BA for short. This paper presents how safety properties speciied in a linear Temporal Logic are automatica...

In this paper, some properties of the periodic shadowing are presented. It is shown that a homeomorphism has the periodic shadowing property if and only if so does every lift of it to the universal covering space. Also, it is proved that continuous mappings on a compact metric space with the periodic shadowing and the average shadowing property also have the shadowing property and then are chao...