The mechanism of ion conduction by potassium channels is one of the central issues in physiology. In particular, it is still unclear how the ion concentration and the membrane voltage drive ion conduction. We have investigated the dynamics of the ion conduction processes in the Kv1.2 pore domain, by molecular dynamics (MD) simulations with several different voltages and ion concentrations. By f...

A readily reversible rise in pH of the medium occurs when unbuffered spinach chloroplasts are illuminated, especially when the initial pH during incubation in the dark is at or below 6.5 (1, 2). This rise in pH had been predicted from an examination of the chemiosmotic mechanisms for phosphorylation detailed by Mitchell (3). It was correlated, in at least a preliminary way, with the existence i...

Ion current fluctuations occurring within open and closed states of a large-conductance locust potassium channel (BK channel) were investigated for the existence of correlation. Both the time series, extracted from the ion current signal, were studied by the autocorrelation function and the detrended fluctuation analysis (DFA) methods. The persistent character of the short- and middle-range cor...

Using the evaporating method, the solubility of potassium Nitrate was determined in various mixtures containing Water and Ethanol at 25°C. The results show that the solubility of KNo3 decreases with increasing the mass percent of Ethanol in the mixtures. This trend is along with decreasing the dielectric constant of Water+Ethanol mixtures. Moreover, it can be concluded that the totqal solubilit...

Previous X-ray studies of have focused on the closed state of the potassium channel. Now the structure of a calcium-activated bacterial potassium channel has revealed the nature of the channel's open state. This provides a first view at high resolution of ion channel gating.

Permeant ions can have significant effects on ion channel conformational changes. To further understand the relationship between ion occupancy and gating conformational changes, we have studied macroscopic and single-channel gating of BK potassium channels with different permeant monovalent cations. While the slopes of the conductance-voltage curve were reduced with respect to potassium for all...

Nucleotide monophosphate kinases (NMPKs) are potential antimicrobial drug targets owing to their role in supplying DNA and RNA precursors. The present work reports the crystal structure of Staphylococcus aureus guanylate monophosphate kinase (SaGMK) at 1.9 A resolution. The structure shows that unlike most GMKs SaGMK is dimeric, confirming the role of the extended C-terminus in dimer formation ...

BACKGROUND Despite the widespread clinical application of ropivacaine, there is little information on the cellular cardiac effects of the drug. In the current study, therefore, the concentration-dependent effects of ropivacaine on action potential morphology and the underlying ion currents were studied and compared with those of bupivacaine in isolated canine ventricular cardiomyocytes. METHO...

Ion channels play a central role in a host of physiological and pathological processes and are the second largest target for existing drugs. There is an increasing need for reliable tools to detect and visualize particular ion channels, but existing solutions suffer from a number of limitations such as high price, poor specificity, and complicated protocols. As an alternative, we produced recom...