Structural and Spectroscopic Investigations of pH-Dependent Mo(V) Species in a Bacterial Sulfite-Oxidizing Enzyme.

Mono-pyranopterin-containing sulfite-oxidizing enzymes (SOEs), including eukaryotic sulfite oxidases and homologous prokaryotic sulfite dehydrogenases (SDHs), are molybdenum enzymes that exist in almost all forms of life, where they catalyze the direct oxidation of sulfite into sulfate, playing a key role in protecting cells and organisms against sulfite-induced damage. To decipher their catalytic mechanism, we have previously provided structural and spectroscopic evidence for direct coordination of HPO to the Mo atom at the active site of the SDH from the hyperthermophilic bacterium (SDH), mimicking the proposed sulfate-bound intermediate proposed to be formed during catalysis. In this work, by solving the X-ray crystallographic structure of the unbound enzyme, we resolve the changes in the hydrogen bonding network in the molybdenum environment that enable the stabilization of the previously characterized phosphate adduct.

Intercostal Lung Hernias Presenting After Minimally Invasive Cardiac Surgery.

Introduction: With the introduction of minimally invasive cardiac surgery, more commonly cases of lung herniation are starting to appear. Acquired lung hernias are classified as postoperative, traumatic, pathologic, and spontaneous. Up to 83% of lung hernias are intercostal.

A Physiological Approach to Explore How Thioredoxin-Glutathione Reductase (TGR) and Peroxiredoxin (Prx) Eliminate HO in Cysticerci of .

Peroxiredoxins (Prxs) and glutathione peroxidases (GPxs) are the main enzymes of the thiol-dependent antioxidant systems responsible for reducing the HO produced via aerobic metabolism or parasitic organisms by the host organism. These antioxidant systems maintain a proper redox state in cells. The cysticerci of tolerate millimolar concentrations of this oxidant.

The transport activity of the multidrug ABC transporter BmrA does not require a wide separation of the nucleotide-binding domains.

ATP-binding cassette (ABC) transporters are ubiquitous membrane proteins responsible for the translocation of a wide diversity of substrates across biological membranes. Some of them confer multidrug or antimicrobial resistance to cancer cells and pathogenic microorganisms, respectively. Despite a wealth of structural data gained in the last two decades, the molecular mechanism of these multidrug efflux pumps remains elusive, including the extent of separation between the two nucleotide-binding domains (NBDs) during the transport cycle.