Polypeptide neurotoxins alter ion channel gating by binding to extracellular receptor sites, even though the voltage sensors are in their S4 transmembrane segments. By analysis of sodium channel chimeras, a beta-scorpion toxin is shown here to negatively shift voltage dependence of activation and enhance closed state inactivation by binding to a receptor site that requires glycine 845 (Gly-845)...

Deletion of a phenylalanine at position 1617 (delF1617) in the extracellular linker between segments S3 and S4 in domain IV of the human heart Na(+) channel (hH1a) has been tentatively associated with long QT syndrome type 3 (LQT3). In a mammalian cell expression system, we compared whole cell, gating, and single-channel currents of delF1617 with those of wild-type hH1a. The half points of the ...

Chronic pain is a common complication of diabetes. The aim of the present study was to characterise pain behaviour in a high fat diet/streptozotocin (HFD/STZ) model of diabetes in the rat, investigate spinal mechanisms, and determine the effects of antidiabetic interventions. Three-week consumption of a high fat diet followed by single injection of STZ (45 mgkg(-1)) produced sustained changes i...

The rotational spectrum of S4 has been observed for the first time in an electrical discharge through sulfur vapor. Two techniques have been used: Fourier transform microwave spectroscopy and long-path millimeter-wave absorption spectroscopy. Small, but systematic shifts of the measured transition frequencies of the normal isotopic species indicate that S4 has C2v symmetry but with a low-lying ...

A field experiment was conducted at Sugarcane Research Station, Tamil Nadu Agricultural University, Sirugamani during (Plant crop) 2017-18 to find out the effect of intercropping and double row planting on growth attributes, yield sugarcane under Sustainable initiative. The experiments were laid in a strip plot design with three replications. main treatments comprised crop geometry viz., M1- 15...

The objective of this study was to evaluate the quality white-fleshed dragon fruit (Hylocereus undatus) at harvest and postharvest determine feasibility harvesting fruits different outer color stages. treatments consisted four peel stages – S1 (<25% red peel), S2 (25%-49% S3 (50% 75% peel) S4 (>75% two evaluation times (at one day after full color), which corresponded 1, 3, 5 7 days for S...

Each of the four subunits in a voltage-gated potassium channel has a voltage sensor domain (VSD) that is formed by four transmembrane helical segments (S1-S4). In response to changes in membrane potential, intramembrane displacement of basic residues in S4 produces a gating current. As S4 moves through the membrane, its basic residues also form sequential electrostatic interactions with acidic ...