Improved Optical and Morphological Properties of Vinyl-Substituted Hybrid Silica Materials Incorporating a Zn-Metalloporphyrin.

This work is focused on a novel class of hybrid materials exhibiting enhanced optical properties and high surface areas that combine the morphology offered by the vinyl substituted silica host, and the excellent absorption and emission properties of 5,10,15,20-tetrakis(-methyl-4-pyridyl)porphyrin-Zn(II) tetrachloride as a water soluble guest molecule. In order to optimize the synthesis procedure and the performance of the immobilized porphyrin, silica precursor mixtures of different compositions were used. To achieve the requirements regarding the hydrophobicity and the porous structure of the gels for the successful incorporation of porphyrin, the content of vinyltriacetoxysilane was systematically changed and thoroughly investigated.

A computational approach to structural properties of glycoside hydrolase family 4 from bacteria.

Structural bioinformatics approaches applied to the alpha- and beta-glycosidases from the GH4 enzyme family reveal that, despite low sequence identity, these enzymes possess quite similar global structural characteristics reflecting a common reaction mechanism. Locally, there are a few distinctive structural characteristics of GH4 alpha- and beta-glycosidases, namely, surface cavities with different geometric characteristics and two regions with highly dissimilar structural organizations and distinct physicochemical properties in the alpha- and beta-glucosidases from Thermotoga maritima. We suggest that these structurally dissimilar regions may be involved in specific protein-protein interactions and this hypothesis is sustained by the predicted distinct functional partners of the investigated proteins.