The ionic atmospheres around nucleic acids play important roles in biological function. Large-scale explicit solvent simulations coupled to experimental assays such as anomalous small-angle x-ray scattering can provide important insights into the structure and energetics of such atmospheres but are time- and resource intensive. In this article, we use classical density functional theory to expl...

Crude wild pear lipoxygenase (LOX) from ripe Kurdistan wild pears was used in this study. Extracted crude LOX was assayed spectrophotometrically for raw, ripe wild pear lipoxygenase and after 7-day storage. The effects of different buffers and pHs, substrate preparations, temperature, inhibitors and metal ions on LOX activity were evaluated at three conditions. The enzyme was most active with H...

Larvae of the freshwater mosquito Aides aegypti (L.) are able to maintain their principal electrolytes against a steep concentration gradient between the haemolymph and the external medium. The concentration of monovalent ions such as Na, K and Cl~ is kept far above that in the external medium by processes of active transport which are located in the anal papillae, the rectum and the Malpighian...

A novel SmtB/ArsR family metalloregulator, denoted BxmR, has been identified and characterized from the cyanobacterium Oscillatoria brevis. Genetic and biochemical evidence reveals that BxmR represses the expression of both bxa1, encoding a CPx-ATPase metal transporter, as well as a divergently transcribed operon encoding bxmR and bmtA, a heavy metal sequestering metallothionein. Derepression o...

The release of monovalent potassium and divalent calcium ions from zwitterionic phosphorylcholine containing poly(2-hydroxyethyl methacrylate) (pHEMA)-based hydrogels was studied and the effects of polymer swelling, ion valence and temperature were investigated. For comparison, ions were loaded during hydrogel formulation or loaded by partitioning following construct synthesis. Using the Koshme...

A membrane-bound adenosine triphosphatase (EC 3.6.1.3) that requires Mg(++) and that is stimulated by monovalent ions has been purified 7- to 8-fold from homogenates of oat (Avena sativa L. Cult. Goodfield) roots by discontinuous sucrose-gradient centrifugation. The enzyme was substrate specific; adenosine triphosphate was hydrolyzed 25 times more rapidly than other nucleoside triphosphates. Th...

Nuclear ion channels remain among the least studied and biophysically characterized channels. Although considerable progress has been made in characterizing calcium release channels in the nuclear membrane, very little is known regarding the properties of nuclear monovalent cationic channels. Here, we describe a method to isolate nuclei from adult skeletal muscle fibers that are suitable for el...