Opening and closing of the central ion-conducting pore in voltage-dependent ion channels is gated by changes in membrane potential. Although a gate residue in the eukaryotic voltage-gated sodium channel has been identified, the minimal molecular determinants of this gate region remain unknown. Here, by measuring the closed- and open-state reactivity of MTSET to substituted cysteines in all the ...

We investigated the effect of the phenylalkylamine Ca(2+) channel inhibitor verapamil on voltage-dependent K(+) (Kv) channels in rabbit coronary arterial smooth muscle cells using a whole-cell patch clamp technique. Verapamil reduced the Kv current amplitude in a concentration-dependent manner. The apparent K(d) value for Kv channel inhibition was 0.82 microM. Although verapamil had no effect o...

Cystic fibrosis transmembrane conductance regulator (CFTR) is an adenosine triphosphate (ATP)-gated chloride channel. ATP-induced dimerization of CFTR's two nucleotide-binding domains (NBDs) has been shown to reflect the channel open state, whereas hydrolysis of ATP is associated with channel closure. Pyrophosphate (PPi), like nonhydrolytic ATP analogues, is known to lock open the CFTR channel ...

RSD 921 is a novel, structurally unique, class I Na+ channel blocking drug under development as a local anaesthetic agent and possibly for the treatment of cardiac arrhythmias. The effects of RSD 921 on wild-type heart, skeletal muscle, neuronal and non-inactivating IFMQ3 mutant neuronal Na+ channels expressed in Xenopus laevis oocytes were examined using a two-electrode voltage clamp. RSD 921 ...

A voltage-dependent, K+-selective ionic channel from sarcoplasmic reticulum of rabbit skeletal muscle has been studied in a planar phospholipid bilayer membrane. The purpose [corrected] of this work is to study the mechanism by which the channel undergoes transitions between its conducting and nonconducting states. Thermodynamic studies show that the "open" and "closed" states of the channel ex...

A memoryless state sequence governing the behavior of a state-dependent channel is to be described causally an encoder wishing communicate over said channel. Given maximal-allowed description rate, we seek that maximizes Shannon capacity. It shown maximum need not achieved by (symbol-by-symbol) description. Such descriptions are, however, optimal when receiver cognizant or allowed depend on mes...

Kv1.2 is a member of the Shaker family of voltage-sensitive potassium channels and contributes to regulation of membrane excitability. The electrophysiological activity of Kv1.2 undergoes tyrosine kinase-dependent suppression in a process involving RhoA. We report that RhoA elicits suppression of Kv1.2 ionic current by modulating channel endocytosis. This occurs through two distinct pathways, o...

objective(s): angiotensin ⅱ type 1 receptor blockers (arbs) represent one of the widely used antihypertensive agents. in addition to anti-hypertension effect, some arbs also show other molecular effects such as activating peroxisome proliferator-activated receptor-γ and so on. here we studied the effects of telmisartan on the rat isolated mesenteric artery rings pre-contracted by phenylephrine ...