Microfabrication techniques are facilitating the creation of microenvironments tailored to neuronal structures and subdomains with unprecedented access and control. The design, fabrication, and properties of microfluidic devices offer significant advantages for addressing unresolved issues of neuronal development. These high-resolution approaches are poised to contribute new insights into mechanisms for restoring neuronal function and connectivity compromised by injury, stress, and neurodegeneration.”
“Lys67 is essential for the hydrolysis reaction mediated by class C beta-lactamases. Its exact catalytic role lies at the center of several different

proposed reaction mechanisms, particularly ATM inhibitor for the deacylation step, and has been intensely debated. Whereas a conjugate base hypothesis postulates that a neutral Lys67 and Tyr150 act together to deprotonate the deacylating water, previous experiments on the K67R mutants of class C beta-lactamases suggested that the role of Lys67 in deacylation is mainly electrostatic, with only a 2- to 3-fold decrease in the rate of the mutant vs the wild

type enzyme. Using the Class C beta-lactamase AmpC, we have reinvestigated the activity of this K67R selleckchem mutant enzyme, using biochemical and structural studies. Both the rates of acylation and deacylation were affected in the AmpC K67R mutant, with a 61-fold decrease in k(cat), the deacylation rate. We have determined the structure of the K67R mutant by X-ray crystallography both in apo and transition state-analog complexed forms, and observed only minimal conformational changes in the catalytic residues relative to the wild type. These results suggest that the arginine side chain is unable to play the same catalytic role as Lys67 in either the acylation or deacylation reactions catalyzed by AmpC. Therefore, PAK5 the activity of this mutant can not be used to discredit the conjugate base hypothesis as previously concluded, although the reaction catalyzed by the K67R mutant itself likely proceeds by an alternative mechanism. Indeed, a manifold

of mechanisms may contribute to hydrolysis in class C beta-lactamases, depending on the enzyme (wt or mutant) and the substrate, explaining why different mutants and substrates seem to support different pathways. For the WT enzyme itself, the conjugate base mechanism may be well favored.”
“Background: P2X(7) receptors intervene with lymphocyte activation and are responsible for multiple processes, including calcium influx. Here, we studied the participation of P2X(7) receptors in disturbed intracellular calcium homeostasis regulation in early-stage chronic kidney disease (CKD). Methods: The study involved 20 healthy volunteers and 20 CKD stage 2-3 patients. The free cytosolic calcium concentration ([Ca2+](i)) was measured using fluorimetry. The P2X(7) pore function was evaluated by the fluorescent dye ethidium bromide.