Biochemical and biophysical properties of hyphomicrobium bacteriophage hyphi30

Hyphomicrobium bacteriophage Hy30 and its nucleic acid were studied to determine some of their biochemical and biophysical properties. The molecular weight of the phage is 55.4 × 10⁶, and its buoyant density is 1.508 g/ml. The nucleic acid of Hy30 is linear, double-stranded DNA with a molecular weight of 29.7 × 10⁶. The guanine-plus-cytosine content of the DNA was 62% as determined from its melting temperature and buoyant density.     

The Mitochondrial Targets of Neuroprotective Drug Vinpocetine on Primary Neuron Cultures,Brain Capillary Endothelial Cells,Synaptosomes, and Brain Mitochondria

Neurochemical Research - Vinpocetine is considered as neuroprotectant drug and used for treatment of brain ischemia and cognitive deficiencies for decades. A number of enzymes, channels and...     

Modification of silver-enhanced sodium transport across toad skin

1. Silver stimulated short-circuit current and transepithelial potential difference. 2. Cysteine inhibited the silver-induced short-circuit current. 3. There was a dose-response inhibition of silver-induced short-circuit current by cysteine. 4. The silver-induced short-circuit current is carried by a net active sodium transfer from the outside to the inside bathing solution.     

Transport energetics of the Na+ pump in Aplysia californica gut

Basolateral membranes of Aplysia californica foregut epithelia contain an ATP-dependent Na+ transporter (Na+ pump). Increased activity of the Na+ pump, coupled to luminal Na+/AIB symporter activity and basolateral membrane depolarization, changed the Na+ transport energetics across the basolateral membrane to a greater extent than the change in Na+ transport energetics across the luminal membrane.     

Phosphate absorption in Aplysia californica gut: glucocorticoid inhibition

Apical membranes of Aplysia californica foregut epithelia contain a sodium-phosphate symporter. Dexamethasone inhibited the absorptive activity of the sodium-phosphate symporter, whereas amiloride had no effect on the sodium-phosphate symporter. It appears that glucocorticoids or their molluscan equivalent play a role in the overall regulation of phosphate homeostasis by the Aplysia californica gut.     

Thyroid-hormone-induced phosphate absorption in Aplysia californica gut is mediated through protein synthesis

The mucosal membranes of Aplysia californica forgut epithelia contain a sodium-phosphate symporter that is stimulated by triiodothyronine. Actinomycin D, puromycin, or cycloheximide inhibited the triiodothyronine-stimulated phosphate absorption. It appears that thyroid hormone manifests its effects on phosphate absorption in the A. californica gut through protein synthesis.     

Sodium-Sulfate Symport by Aplysia californica Gut

Sulfate transport across plasma membranes has been described in a wide variety of organisms and cell types including gastrointestinal epithelia. Sulfate transport can be coupled to proton, sodium symport or antiport processes involving chloride or bicarbonate. It had previously been observed in Aplysia gut that sulfate was actively absorbed. To understand the mechanism for this transport, short-circuited Aplysia californica gut was used. Bidirectional transepithelial fluxes of both sodium and sulfate were measured to see whether there was interaction between the fluxes. The net mucosal-to-serosal flux of Na(+) was enhanced by the presence of sulfate and it was abolished by the presence of serosal ouabain. Similarly, the net mucosal-to-serosal flux of sulfate was dependent upon the presence of Na(+) and was abolished by the presence of serosal ouabain. Theophylline, DIDS and bumetanide, added to either side, had no effect on transepithelial potential difference or short-circuit current in the Aplysia gut bathed in a Na2SO4 seawater medium. However, mucosal thiosulfate inhibited the net mucosal-to-serosal fluxes of both sulfate and Na(+) and the thiosulfate-sensitive Na(+) flux to that of sulfate was 2:1. These results suggest the presence of a Na-SO4 symporter in the mucosal membrane of the Aplysia californica foregut absorptive cell.