scholarly journals The scorpion toxin and the potassium channel

eLife ◽  
2013 ◽  
Vol 2 ◽  
Author(s):  
Kenton J Swartz

The structure of a complex containing a toxin bound to a potassium ion channel has been solved for the first time, revealing how scorpions have designed toxins that can recognize and target the filter that controls the movement of potassium ions through these channels.

Author(s):  
Patricia S. Langan ◽  
Venu Gopal Vandavasi ◽  
Brendan Sullivan ◽  
Joel Harp ◽  
Kevin Weiss ◽  
...  

The mechanism by which potassium ions are transported through ion channels is currently being investigated by several groups using many different techniques. Clarification of the location of water molecules during transport is central to understanding how these integral membrane proteins function. Neutrons have a unique sensitivity to both hydrogen and potassium, rendering neutron crystallography capable of distinguishing waters from K+ ions. Here, the collection of a complete neutron data set from a potassium ion channel to a resolution of 3.55 Å using the Macromolecular Neutron Diffractometer (MaNDi) is reported. A room-temperature X-ray data set was also collected from the same crystal to a resolution of 2.50 Å. Upon further refinement, these results will help to further clarify the ion/water population within the selectivity filter of potassium ion channels.


2001 ◽  
Vol 80 (4) ◽  
pp. 1659-1669 ◽  
Author(s):  
Meng Cui ◽  
Jianhua Shen ◽  
James M. Briggs ◽  
Xiaomin Luo ◽  
Xiaojian Tan ◽  
...  

Author(s):  
Ryan Collins

The electrical signaling capabilities of neurons depend on the flows of ions into and out of their axons. Potassium ions exit an axon’s interior through a potassium channel or pore that connects the intracellular region with the extracellular region. The channel opens, or is activated, allowing potassium ions to exit. The channel then undergoes a blocking transition in which the channel is physically open but is blocked by some part of the larger channel molecule. This blocking process is called inactivation, and the physics by which it might occur forms the topic of our investigation. The N-terminus region of the Drosophila shaker potassium ion channel was identified by Hoshi et al as having an important role in channel inactivation. Using the last 19 amino acids in the N-terminus region, a mass and net charge were calculated. We investigated two forces that might affect the motion of this N-terminus mass (tentatively identified as the blocking or inactivation particle): the magnetic field effects due to potassium ion current in the channel, and an electric force due to the decreasing density of potassium ions from the intracellular region. Time-of-flight calculations were calculated for the inactivation particle. These times will be discussed in terms of typical inactivation processes.


Planta Medica ◽  
2015 ◽  
Vol 81 (16) ◽  
Author(s):  
A Vasas ◽  
P Orvos ◽  
L Tálosi ◽  
P Forgo ◽  
G Pinke ◽  
...  

2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Ozada Khamdiyeva ◽  
Zhanerke Tileules ◽  
Gulminyam Baratzhanova ◽  
Anastassiya Perfilyeva ◽  
Leyla Djansugurova

Abstract Background Epilepsy is one of the most common and heterogeneous neurological diseases. The main clinical signs of the disease are repeated symptomatic or idiopathic epileptic seizures of both convulsive and non-convulsive nature that develop against a background of lost or preserved consciousness. The genetic component plays a large role in the etiology of idiopathic forms of epilepsy. The study of the molecular genetic basis of neurological disorders has led to a rapidly growing number of gene mutations known to be involved in hereditary ion channel dysfunction. The aim of this research was to evaluate the involvement of single-nucleotide variants that modify the function of genes (SCN1A, KCNT1, KCNTС1, and KCNQ2) encoding sodium and potassium ion channel polypeptides in the development of epilepsy. Results De novo mutations in the sodium channel gene SCN1A c.5347G>A (p. Ala1783Thr) were detected in two patients with Dravet syndrome, with a deletion in exon 26 found in one. Three de novo mutations in the potassium channel gene KCNT1 c.2800G>A (p. Ala934Thr), were observed in two patients with temporal lobe epilepsy (TLE) and one patient with residual encephalopathy. Moreover, a control cohort matched to the case cohort did not reveal any SNVs among conditionally healthy individuals, supporting the pathogenic significance of the studied SNVs. Conclusion Our results are supported by literature data showing that the sodium ion channel gene SCN1A c.5347G>A mutation may be involved in the pathogenesis of Dravet syndrome. We also note that the c.2800G>A mutation in the potassium channel gene KCNT1 can cause not only autosomal dominant nocturnal frontal lobe epilepsy (ADNFLE) but also other forms of epilepsy. To treat pathogenetic mutations that accelerate the function of sodium and potassium ion channels, we recommend ion channel blockade drug therapy.


Heart ◽  
2013 ◽  
Vol 99 (Suppl 3) ◽  
pp. A187.1-A187
Author(s):  
Wulasihan Muhuyati ◽  
Ma Xiao-yun ◽  
Lu Wu-hong ◽  
Yang Yu-chun ◽  
Nan Yue-long

1995 ◽  
Vol 14 (21) ◽  
pp. 5170-5178 ◽  
Author(s):  
H. Schrempf ◽  
O. Schmidt ◽  
R. Kümmerlen ◽  
S. Hinnah ◽  
D. Müller ◽  
...  

eLife ◽  
2013 ◽  
Vol 2 ◽  
Author(s):  
David E Clapham

Human sperm cells rely on an unusual type of potassium ion channel.


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