Tracking W-Formate Dehydrogenase Structural Changes During Catalysis and Enzyme Reoxidation.

Metal-dependent formate dehydrogenases (Fdh) catalyze the reversible conversion of CO to formate, with unrivalled efficiency and selectivity. However, the key catalytic aspects of these enzymes remain unknown, preventing us from fully benefiting from their capabilities in terms of biotechnological applications. Here, we report a time-resolved characterization by X-ray crystallography of the Hildenborough SeCys/W-Fdh during formate oxidation.

Spectroscopic and Structural Characterization of Reduced Hildenborough W-FdhAB Reveals Stable Metal Coordination during Catalysis.

Metal-dependent formate dehydrogenases are important enzymes due to their activity of CO reduction to formate. The tungsten-containing FdhAB formate dehydrogenase from Hildenborough is a good example displaying high activity, simple composition, and a notable structural and catalytic robustness. Here, we report the first spectroscopic redox characterization of FdhAB metal centers by EPR.

Chitosan and polyethylene glycol based membranes with antibacterial properties for tissue regeneration.

The prevention of microbial infections associated with implantable medical devices and superficial wounds represents one of the main research strategies in the field of biomaterials. The present study reports on the development of composite membranes of Chitosan (CS)-Polyethylene glycol (PEG) matrix, incorporating particles of biphasic calcium phosphate (BCP), zinc oxide (ZnO) and copper oxide (CuO). The properties that are relevant for intended applications in tissue regeneration and antibacterial coatings of implants were assessed.

Doping β-TCP as a Strategy for Enhancing the Regenerative Potential of Composite β-TCP-Alkali-Free Bioactive Glass Bone Grafts. Experimental Study in Rats.

The present work aims at evaluating the potential gains derived from partially replacing calcium in resorbable β-tricalcium phosphate (β-TCP) by two different molar percentages of strontium (5, 10) and zinc (1, 2), concomitantly with a fixed molar percentage (0.5) of manganese. Synthetic granular composite bone filling grafts consisting of doped β-TCP and an alkali-free bioactive glass were prepared and implanted in ~4 mm diameter bone defects drilled in the calvaria of Wistar rats used as animal models.

Oxidative inactivation of NiFeSe hydrogenase.

We propose a resolution to the paradox that spectroscopic studies of NiFeSe hydrogenase have not revealed any major signal attributable to Ni(III) states formed upon reaction with O2, despite the fact that two inactive states are formed upon either aerobic or anaerobic oxidation.

Computerized tomography findings in Fahr's syndrome.

We analyzed computerized tomography (CT) findings in six patients with Fahr's syndrome. They presented calcifications in basal ganglia, dentate nucleus, subcortical region and semioval center, due to alteration in calcium metabolism or due to senile relative hypoxemic state. The image pattern was not strictly related with etiology, although some differences in dystrophic senile calcifications (the only one present in semioval center and absent in subcortical region).