This paper describes the effects of a toxin from the scorpion Centruroides suffusus suffusus on frog skeletal muscle. The main findings are the following, (i) Centruroides toxin (CssII) blocks the early phase of the inward sodium current in the muscle that arises from influx via Na+ channels in the surface membrane, but it does not affect the late phase of the inward current that represents flu...

When Arbacia punctulata spermatozoa are incubated in seawater containing ammonium hydroxide (pH 8.8), the sperm plasma membrane-bound guanylate cyclase is dephosphorylated, its electrophoretic mobility increases (from an apparent molecular mass of 160 to 150 kD), and its enzymatic activity decreases 3.5-fold. Transfer of these cells into ammonium-free seawater (pH 7.4) results in the rephosphor...

A method for the isolation of the plasma membranes of the mouse leukemic cell P388 is described. The method includes surface labeling of the cell membrane with 125I. The 125I specific activity of the plasma membrane preparation is 10- to 13-fold higher than that of the cell homogenate; enzyme assays and electron microscopy further corroborate the purity of the P388 plasma membrane preparation. ...

in this study, effects of buthus eupeus venom on chick biventer cervices nerve-muscle preparation were investigated by twitch tension method. the venom, at 1.3 ?g/ml, increased contractile responses in indirect stimulations. these effects were milder in direct muscle stimulations. it also caused significant enhancement in postjunctional sensitivity as assessed by responses to exogenous acetylch...

Laser microdissection is an invaluable tool in medical research that facilitates collecting specific cell populations for molecular analysis. Diversity of research targets (e.g., cancerous and precancerous lesions in clinical and animal research, cell pellets, rodent embryos, etc.) and varied scientific objectives, however, present challenges toward establishing standard laser microdissection p...

Membrane-based separation technology has attracted great interest in many separation fields due to its advantages of easy-operation, energy-efficiency, easy scale-up, and environmental friendliness. The development of novel membrane materials and membrane structures is an urgent demand to promote membrane-based separation technology. Graphene oxide (GO), as an emerging star nano-building materi...

A detailed protocol for crystallizing membrane proteins by using lipidic mesophases is described. This method has variously been referred to as the lipidic cubic phase or in meso method. The method has been shown to be quite versatile in that it has been used to solve X-ray crystallographic structures of prokaryotic and eukaryotic proteins, proteins that are monomeric, homo- and hetero-multimer...

A procedure was developed for the large scale preparation of membranes from pig atria which are enriched 10-13 fold in the muscarinic acetylcholine receptor. The procedure involved differential centrifugation and sucrose-gradient centrifugation in solutions containing 150 mM-NaClO4 and 5 mM-EDTA to minimize membrane aggregation. The final membrane preparation bound about 1.1 pmol of L-quinuclid...

Herein we propose a novel approach to the preparation of quasi-1D nanostructures with various chemical compositions based on infiltration of colloidal solution into the asymmetric anodic alumina membrane. The proposed technique was successfully applied for the preparation of ordered arrays of the magnetically hard anisotropic hexaferrite nanostructures.