To study the size and structure of the Na,K-pump molecule, the ultrastructure of phospholipid vesicles was examined after incorporation of purified Na,K-ATPase which catalyzes active coupled transport of Na+ and K+ in a ratio close to 3Na/2K. The vesicles were analyzed by thin sectioning and freeze-fracture electron microscopy after reconstitution with different ratios of Na,K-ATPase protein to...

Na(+)/K(+)-ATPase (sodium pump) is an important target for the development of botanical pesticide as it is responsible for transforming chemical energy in ATP to osmotic work and maintaining electrochemical Na(+ )and K(+ )gradients across the cell membrane of most animal cells. Celangulin IV (C-IV) and V (C-V), which are isolated from the root bark of Celastrus angulatus, are the major active i...

Epinephrine and amylin stimulate glycogenolysis, glycolysis, and Na+-K+-ATPase activity in skeletal muscle. However, it is not known whether these hormones stimulate glycolytic ATP production that is specifically coupled to ATP consumption by the Na+-K+pump. These studies correlated glycolysis with Na+-K+-ATPase activity in resting rat extensor digitorum longus and soleus muscles incubated at 3...

Soil salinity is a major abiotic stress that results in considerable crop yield losses worldwide. However, some plant genotypes show a high tolerance to soil salinity, as they manage to maintain a high K+/Na+ ratio in the cytosol, in contrast to salt stress susceptible genotypes. Although, different plant genotypes show different salt tolerance mechanisms, they all rely on the regulation and fu...

Vesicles containing a purified shark rectal gland (sodium + potassium)-activated adenosine triphosphatase-(NaK ATPase) were prepared by dialyzing for 2 days egg lecithin, cholate, and the NaK ATPase purified from the rectal gland of Squalus acanthias. These vesicles were capable of both Na+ and K+ transport. Studies of K+ transport were made by measuring the ATP-stimulated transport outward of ...

Sodium efflux from rings of frog stomach muscle was measured at 5 degrees and 15 degrees C in three different steady states. After incubation in normal, K-free, or ouabain (10(-4)M) solutions, intracellular cations stabilized at markedly differing levels. At 5 degrees C, inhibition of Na extrusion was shown in the rate coefficients for (22)Na efflux, which were slightly smaller in K-free than i...

The membrane potential of frog sartorius muscle fibers in a Cl- and Na-free Ringer's solution when sucrose replaces NaCl is about the same as that in normal Ringer's solution. The K(+) efflux is also about the same in the two solutions but muscles lose K and PO(4) in sucrose Ringer's solutions. The membrane potential in sucrose Ringer's solution is equal to that given by the Nernst equation for...

AbstractThis study was undertaken to better understand the probable mechanisms of salt stress tolerance induced by seed priming of salicylic acid (SA) in barley. The barley seeds were pre-soaked by SA or water and then sown under different saline watering regimes including 0.62 (tapwater), 5, 10 and 15 dS m-1 in petri dishes and trend of water absorbing, seedling growth, germination rate and pe...

The presence of (Na(+)+K+)ATPase activity in CL14 clone and NIH NTY strain of Trypanosoma cruzi epimastigotes is demonstrated. A Na+ plus K+ stimulated ATPase activity is found in both strains. The optimal Na+/K+ ratio is 5:1 and 9:1 in CL14 clone and NIH NTY strain, respectively. In both strains, vanadate completely inhibits the ouabain-sensitive ATPase activity indicating that it belongs to t...

In Source Location (SL) problems the goal is to select a minimum cost source set S such that the connectivity from S to any node v is at least the demand dv of v. In Network Augmentation (NA) problems we are given a graph G = (V,E) and an edge-set F on V , edge-costs on F or node-costs on V , and connectivity requirements {rsv : sv ∈ D} on a set D of “demand edges”. The goal is to compute a min...