The simple carbon-carbon scission of ethane is investigated by performing quantum mechanical calculations. The approach described in this paper was developed to determine dissociation rate constants for both small and large organic molecules, such as n-alkanes or alkyl-benzenes, for reasonable ranges of computation time and accuracy. The methodology that we propose is based on generalized trans...

Incubation of the isolated acrosomal bundles of Limulus sperm with skeletal muscle actin results in assembly of actin onto both ends of the bundles. These cross-linked bundles of actin filaments taper, thus allowing one to distinguish directly the preferred end for actin assembly from the nonpreferred end; the preferred end is thinner. Incubation with actin in the presence of equimolar phalloid...

A B S T R AC T Lipid metabolites, free fatty acids and lysophospholipids, modify the function of membrane proteins including ion channels. Such alterations can occur through signal transduction pathways, but may also result from "direct" effects of the metabolite on the protein. To investigate possible mechanisms for such direct effects, we examined the alterations of gramicidin channel functio...

BACKGROUND Recently, we reported an information density theory and an analysis of three-parameter plus shorter scan than conventional method (3P+) for the amyloid-binding ligand [11C]Pittsburgh compound B (PIB) as an example of a non-highly reversible positron emission tomography (PET) ligand. This article describes an extension of 3P + analysis to noninvasive '3P++' analysis (3P + plus use of ...

Titanium, a high-temperature tolerance metal, is preferred as neutron targets due to high hydrogen storage capacity. Therefore, there need understand the interaction and dynamical behaviours of isotopes with Ti which investigated by means linear combination atomic orbitals projector augmented wave (PAW) potential within density functional theoretical framework. The isotope studied incorporating...

The equilibrium constant of the phosphoglyceromutase reaction was determined over a range of pH (5.4-7.9), in solutions of different ionic strength (0.06-0.3) and in the presence of Mg(2+), at 30 degrees C and at 20 degrees C. The values obtained (8.65-11.65) differ substantially from previously published values. The third acid dissociation constants were redetermined for 2- and 3-phosphoglycer...

We investigated the ability of the muscarinic antagonist p-fluorohexahydrosiladifenidol to inhibit muscarinic agonist-induced contractions and phosphoinositide hydrolysis in the guinea pig ileum and trachea. This antagonist displayed higher potency at blocking oxotremorine-M-induced contractions of the ileum compared with those of the trachea. When estimated using a simple model for competitive...

Edwards 1 has recently described the use of the ultra-violet spectrophotometer to measure the dissociation constant of salicylamide. In a search for a method of analysis of the insecticide Parathion, it was noticed that one of its decomposition products, p-nitrophenol, had an ultra-violet spectrum of an unusually simple nature, consisting of two bands, one of which was enhanced in alkaline solu...

The interactions of dipyridamole with alpha(1) acid glycoprotein of plasma and with human platelets are related to inhibition of adenosine uptake by platelets. Binding studies by equilibrium gel filtration suggested that 1 mol of dipyridamole binds per mol of alpha(1) acid glycoprotein with a dissociation constant of 1.6 muM. Platelets contain two populations of binding sites, one with high and...

The properties of the cGMP-dependent channel present in membrane vesicles prepared from intact isolated bovine rod outer segments (ROS) were investigated with the optical probe neutral red. The binding of neutral red is sensitive to transport of cations across vesicular membranes by the effect of the translocated cations on the surface potential at the intravesicular membrane/water interface (S...