Radiolabelled saxitoxin has been used as a chemical marker for the voltage-dependent sodium channels expressed in the plasmalemma of rabbit Schwann cells in culture. Proteolytic enzymes destroy this saxitoxin-binding capacity, which gradually reappears with an exponential time constant of about 3.1 days. Exposure of cultured Schwann cells to tunicamycin, an inhibitor of glycosylation, leads to ...

Blood-depressing substance I (BDS-I), a 43 amino-acid peptide from sea anemone venom, is used as a specific inhibitor of Kv3-family potassium channels. We found that BDS-I acts with even higher potency to modulate specific types of voltage-dependent sodium channels. In rat dorsal root ganglion (DRG) neurons, 3 μM BDS-I strongly enhanced tetrodotoxin (TTX)-sensitive sodium current but weakly inh...

Sodium channels are one of the most intensively studied drug targets. Sodium channel inhibitors (e.g., local anesthetics, anticonvulsants, antiarrhythmics and analgesics) exert their effect by stabilizing an inactivated conformation of the channels. Besides the fast-inactivated conformation, sodium channels have several distinct slow-inactivated conformational states. Stabilization of a slow-in...

The Slack and Slick genes encode potassium channels that are very widely expressed in the central nervous system. These channels are activated by elevations in intracellular sodium, such as those that occur during trains of one or more action potentials, or following activation of non-selective cationic neurotransmitter receptors such as AMPA receptors. This review covers the cellular and molec...

channelopathies were known, but most of these drugs were used empirically and were found to act on ion channels afterward. Now our knowledge about their role in diseases have validated ion channels as very promising druggable targets. What are the difficulties encountered in ion channel drug discovery? A major problem of ion channel drugs regards the side effects. An ion channel type is often e...

In both tetrodotoxin-resistant (TTX-R) and tetrodotoxin-sensitive (TTX-S) sodium channels, deltamethrin greatly prolonged the current during step depolarizing pulse and caused a large and prolonged slow tail current. The activation was shifted by 20 mV in the hyperpolarizing direction. These changes in channel kinetics account for the prolongation of action potential, membrane depolarization an...

The X-ray structure of the bacterial sodium channel NavAb provides a new template for the study of sodium and calcium channels. Unlike potassium channels, NavAb contains P2 helices in the outer-pore region. Because the sequence similarity between eukaryotic and prokaryotic sodium channels in this region is poor, the structural similarity is unclear. We analyzed it by using experimental data on ...

A subset of potassium channels is regulated primarily by changes in the cytoplasmic concentration of ions, including calcium, sodium, chloride, and protons. The eight members of this subfamily were originally all designated as calcium-activated channels. More recent studies have clarified the gating mechanisms for these channels and have documented that not all members are sensitive to calcium....

Cardiac sodium channels are integral membrane proteins whose structure is not known at atomic level yet and their molecular kinetics is still being studied through mathematical modeling. This study has focused on adapting an existing model of cardiac Na channel to analyze molecular kinetics of channels at 9-37°C. Irvine et al developed a Markov model for Na channel using Neuronal Network Model ...

Cardiac sodium channels are integral membrane proteins whose structure is not known at atomic level yet and their molecular kinetics is still being studied through mathematical modeling. This study has focused on adapting an existing model of cardiac Na channel to analyze molecular kinetics of channels at 9-37°C. Irvine et al developed a Markov model for Na channel using Neuronal Network Model ...