A universal strategy for high-yield production of soluble and functional clostridial collagenases in E. coli

Clostridial collagenases are foe and friend: on the one hand, these enzymes enable host infiltration and colonization by pathogenic clostridia, and on the other hand, they are valuable biotechnological tools due to their capacity to degrade various types of collagen and gelatine. However, the demand for high-grade preparations exceeds supply due to their pathogenic origin and the intricate purification of homogeneous isoforms. We present the establishment of an Escherichia coli expression system for a variety of constructs of collagenase G (ColG) and H (ColH) from Clostridium histolyticum and collagenase T (ColT) from Clostridium tetani, mimicking the isoforms in vivo. Based on a setup of five different expression strains and two expression vectors, 12 different constructs were expressed, and a flexible purification platform was established, consisting of various orthogonal chromatography steps adaptable to the individual needs of the respective variant. This fast, cost-effective, and easy-to-establish platform enabled us to obtain at least 10 mg of highly pure mono-isoformic protein per liter of culture, ideally suited for numerous sophisticated downstream applications. This production and purification platform paves the way for systematic screenings of recombinant collagenases to enlighten the biochemical function and to identify key residues and motifs in collagenolysis

Płytki ceramiczne. Badania mikroskopowe tekstur w odniesieniu do wytrzymałości na zginanie

Płytki gresowe są wytwarzane głównie z glinki kaolinowej, kwarcu i skaleni. Wiele właściwości technicznych, w tym odporność na zginanie, są związane z teksturą materiału w skali mikroskopowej. Najważniejszymi cechami są: zawartość, rozmiar i kształt różnych ziaren, w tym większych ziaren kwarcu, kryształów mullitu, fazy amorficznej bogatej w krzemionką i porowatości. Zrozumienie zależności pomiędzy mikrostrukturą a odpornością na zginanie może prowadzić do opracowania efektywniejszych metod wytwarzania cieńszych płytek o większych wymiarach.Porcelain tiles are sintered ceramic material made mainly from ball clays, quartz and feldspars. Many technical feateurs, including bending strength, are related to the microtexture of porcelain stoneware. Most important features are content, size and shape of different grains. These include large particles of filler (quartz), mullite crystals, a silica-rich amorphous phase and porosity. The understanding of the relationship between the microstructure and the bending strength of porcelain stoneware can lead to the development the manufacturing of thinner tiles with higher dimensions

Crystallization and preliminary X-ray characterization of the catalytic domain of collagenase G from Clostridium histolyticum

The catalytic domain of collagenase G from C. histolyticum was expressed in E. coli BL21 (DE3) and purified using affinity and size-exclusion column-chromatographic methods. Crystals were obtained at 290 K by the sitting-drop vapour-diffusion method and diffraction data have been collected to 2.75 Å resolution