scholarly journals Persistent sodium current blockers can suppress seizures caused by loss of low‐threshold D‐type potassium currents: Predictions from an in silico study of K v 1 channel disorders

2020 ◽  
Vol 5 (1) ◽  
pp. 86-96 ◽  
Author(s):  
Jiaxin Du ◽  
Viktor Vegh ◽  
David C. Reutens
Keyword(s):  
In Silico ◽  
Sodium Current ◽  
Potassium Currents ◽  
Persistent Sodium Current ◽  
In Silico Study ◽  
Low Threshold

scholarly journals Persistent Sodium and Calcium Currents Cause Plateau Potentials in Motoneurons of Chronic Spinal Rats

2003 ◽  
Vol 90 (2) ◽  
pp. 857-869 ◽  
Author(s):  
Yunru Li ◽  
David J. Bennett
Keyword(s):  
Spinal Cord ◽  
Sodium Current ◽  
Negative Slope ◽  
Primary Role ◽  
Persistent Sodium Current ◽  
Plateau Potentials ◽  
Spike Threshold ◽  
Low Threshold ◽  
Chronic Spinal Rats ◽  
Initial Peak

After chronic spinal cord injury motoneurons exhibit large plateau potentials (sustained depolarizations triggered by brief inputs) that play a primary role in the development of muscle spasms and spasticity (Bennett et al. 2001a , b ). The present study examined the voltage-gated persistent inward currents (PICs) underlying these plateaus. Adult rats were spinalized at the S2 sacral spinal level and after 2 mo, when spasticity developed, intracellular recordings were made from motoneurons below the injury. For recording, the whole sacrocaudal spinal cord was removed and maintained in vitro in normal artificial cerebral spinal fluid (nACSF), without application of neuromodulators. During a slow triangular voltage-clamp command (ramp) a PIC was activated with a threshold of –54.2 ± 4.8 mV (similar to plateau threshold), with a peak current of 2.88 ± 0.95 nA and produced a pronounced negative-slope region in the V–I relation. This PIC was in part mediated by Cav1.3 L-type calcium channels because it was low threshold and significantly reduced by 10 to 20 μM nimodipine or 400 μM Cd2+. The PIC that remained during a calcium channel blockade (in Cd2+) was completely and rapidly blocked by tetrodotoxin (TTX; 0.5 to 2 μM), and thus was a TTX-sensitive persistent sodium current. This persistent sodium current was activated rapidly about 7 mV below the spike threshold (spike threshold –46.1 ± 4.5 mV), contributed approximately 1/2 of the initial peak of the total PIC, inactivated partly to contribute only approximately 1/3 of the sustained PIC (at 5 to 10 s), and deactivated rapidly with hyperpolarization (<50 ms). When TTX was added to the bath first, the nimodipine-sensitive persistent calcium current (L-type) was seen in isolation; it was slowly activated (>250 ms), had a low but variable threshold (either slightly above or below the spike threshold), contributed the other approximately 1/2 of the initial peak of the total PIC (before TTX), did not usually inactivate with time (contributed approximately two-thirds of the sustained PIC), and deactivated slowly with hyperpolarization to rest (in >300 ms). In summary, low-threshold persistent calcium (Cav1.3) and sodium currents spontaneously develop in motoneurons of chronic spinal rats and these enable large, rapidly activated plateaus that ultimately lead to spasticity.

In Silico Study of Structural and Geometrical Requirements of Natural Sesquiterpene Lactones with Trypanocidal Activity

2013 ◽  
Vol 13 (10) ◽  
pp. 1407-1414 ◽  
Author(s):  
L. Fabian ◽  
V. Sulsen ◽  
F. Frank ◽  
S. Cazorla ◽  
E. Malchiodi ◽  
...  
Keyword(s):  
In Silico ◽  
Sesquiterpene Lactones ◽  
Trypanocidal Activity ◽  
In Silico Study

In Silico Study of 1, 4 Alpha Glucan Branching Enzyme and Substrate Docking Studies

2020 ◽  
Vol 17 (1) ◽  
pp. 40-50
Author(s):  
Farzane Kargar ◽  
Amir Savardashtaki ◽  
Mojtaba Mortazavi ◽  
Masoud Torkzadeh Mahani ◽  
Ali Mohammad Amani ◽  
...  
Keyword(s):  
Phylogenetic Tree ◽  
In Silico ◽  
Alpha Helix ◽  
In Silico Analysis ◽  
Glycogen Storage ◽  
Docking Studies ◽  
Random Coil ◽  
Special Topic ◽  
Industrial Biotechnology ◽  
In Silico Study

Background: The 1,4-alpha-glucan branching protein (GlgB) plays an important role in the glycogen biosynthesis and the deficiency in this enzyme has resulted in Glycogen storage disease and accumulation of an amylopectin-like polysaccharide. Consequently, this enzyme was considered a special topic in clinical and biotechnological research. One of the newly introduced GlgB belongs to the Neisseria sp. HMSC071A01 (Ref.Seq. WP_049335546). For in silico analysis, the 3D molecular modeling of this enzyme was conducted in the I-TASSER web server. Methods: For a better evaluation, the important characteristics of this enzyme such as functional properties, metabolic pathway and activity were investigated in the TargetP software. Additionally, the phylogenetic tree and secondary structure of this enzyme were studied by Mafft and Prabi software, respectively. Finally, the binding site properties (the maltoheptaose as substrate) were studied using the AutoDock Vina. Results: By drawing the phylogenetic tree, the closest species were the taxonomic group of Betaproteobacteria. The results showed that the structure of this enzyme had 34.45% of the alpha helix and 45.45% of the random coil. Our analysis predicted that this enzyme has a potential signal peptide in the protein sequence. Conclusion: By these analyses, a new understanding was developed related to the sequence and structure of this enzyme. Our findings can further be used in some fields of clinical and industrial biotechnology.

In Silico Study of Ethylene Biosynthesis: Seeking New Effectors of ACC Synthase and ACC Oxidase

2016 ◽  
Vol 11 (3) ◽  
pp. 346-356
Author(s):  
Nada Ayadi ◽  
Sarra Aloui ◽  
Rabeb Shaiek ◽  
Oussama Rokbani ◽  
Faten Raboud ◽  
...  
Keyword(s):  
In Silico ◽  
Acc Oxidase ◽  
Acc Synthase ◽  
Ethylene Biosynthesis ◽  
In Silico Study

In Silico Identification of a Potent Arsenic Based Approved Drug Darinaparsin against SARS-CoV-2: Inhibitor of RNA Dependent RNA polymerase (RdRp) and Essential Proteases

2020 ◽  
Vol 20 ◽  
Author(s):  
Trinath Chowdhury ◽  
Gourisankar Roymahapatra ◽  
Santi M. Mandal
Keyword(s):  
Rna Polymerase ◽  
Viral Entry ◽  
In Silico ◽  
Rna Dependent Rna Polymerase ◽  
Replication Complex ◽  
In Silico Study ◽  
Life Threatening ◽  
In Vivo Analysis ◽  
3Cl Protease

Background: COVID-19 is a life threatening novel corona viral infection to our civilization and spreading rapidly. Terrific efforts are generous by the researchers to search for a drug to control SARS-CoV-2. Methods: Here, a series of arsenical derivatives were optimized and analyzed with in silico study to search the inhibitor of RNA dependent RNA polymerase (RdRp), the major replication factor of SARS-CoV-2. All the optimized derivatives were blindly docked with RdRp of SARS-CoV-2 using iGEMDOCK v2.1. Results: Based on the lower idock score in the catalytic pocket of RdRp, darinaparsin (-82.52 kcal/mol) revealed most effective among them. Darinaparsin strongly binds with both Nsp9 replicase protein (-8.77 kcal/mol) and Nsp15 endoribonuclease (-8.3 kcal/mol) of SARS-CoV-2 as confirmed from the AutoDock analysis. During infection, the ssRNA of SARS-CoV2 is translated into large polyproteins forming viral replication complex by specific proteases like 3CL protease and papain protease. This is also another target to control the virus infection where darinaparsin also perform the inhibitory role to proteases of 3CL protease (-7.69 kcal/mol) and papain protease (-8.43 kcal/mol). Conclusion: In host cell, the furin protease serves as a gateway to the viral entry and darinaparsin docked with furin protease which revealed a strong binding affinity. Thus, screening of potential arsenic drugs would help in providing the fast invitro to in-vivo analysis towards development of therapeutics against SARS-CoV-2.

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