SOD1 in amyotrophic lateral sclerosis development – in silico analysis and molecular dynamics of A4F and A4V variants

Amyotrophic Lateral Sclerosis (ALS) is the most frequent motor neuron disorder, with a significant social and economic burden. ALS remains incurable, and the only drugs approved for its treatments confers a survival benefit of a few months for the patients. Missense mutations in superoxide dismutase 1 (SOD1), a major cytoplasmic antioxidant enzyme, has been associated with ALS development, accounting for 23% of its familial cases and 7% of all sporadic cases. This work aims to characterize in silico the structural and functional effects of SOD1 protein variants. Missense mutations in SOD1 were compiled from the literature and databases. Twelve algorithms were used to predict the functional and stability effects of these mutations. ConSurf was used to estimate the evolutionary conservation of SOD1 amino-acids. GROMACS was used to perform molecular dynamics (MD) simulations of SOD1 wild-type and variants A4V, D90A, H46R, and I113T, which account for approximately half of all ALS-SOD1 cases in the United States, Europe, Japan, and United Kingdom, respectively. 233 missense mutations in SOD1 protein were compiled from the databases and literature consulted. The predictive analyses pointed to an elevated rate of deleterious and destabilizing predictions for the analyzed variants, indicating their harmful effects. The ConSurf analysis suggested that mutations in SOD1 mainly affect conserved and possibly functionally essential amino acids. The MD analyses pointed to flexibility and essential dynamics alterations at the electrostatic and metal-binding loops of variants A4V, D90A, H46R, and I113T that could lead to aberrant interactions triggering toxic protein aggregation. These alterations may have harmful implications for SOD1 and explain their association with ALS. Understanding the effects of SOD1 mutations on protein structure and function facilitates the design of further experiments and provides relevant information on the molecular mechanism of pathology, which may contribute to improvements in existing treatments for ALS.

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In vitro evaluation and molecular dynamics, DFT guided investigation of antimalarial activity of ethnomedicinally used Coptis teeta Wall

Combinatorial Chemistry & High Throughput Screening ◽

10.2174/1386207324666210118095503 ◽

2021 ◽

Vol 24 ◽

Author(s):

Ashis Kumar Goswami ◽

Hemanta Kumar Sharma ◽

Neelutpal Gogoi ◽

Ankita Kashyap ◽

Bhaskar Jyoti Gogoi

Keyword(s):

Molecular Dynamics ◽

In Silico ◽

Density Functional ◽

Antimalarial Activity ◽

In Silico Analysis ◽

Dynamics Simulation ◽

Discovery Studio ◽

North East ◽

Silico Analysis

Background: Malaria is caused by different species of Plasmodium; among which P. falciparum is the most severe. Coptis teeta is an ethnomedicinal plant of enormous importance for tribes of north east India. Objective: In this study, the anti malarial activity of the methanol extracts of Coptis teeta was evaluated in vitro and lead identification via in silico study. Method: On the basis of the in vitro results, in silico analysis by application of different modules of Discovery Studio 2018 was performed on multiple targets of P. falciparum taking into consideration some of the compounds reported from C. teeta. Results: The IC50 of the methanol extract of Coptis teeta 0.08 µg/ml in 3D7 strain and 0.7 µg/ml in Dd2 strain of P. falciparum. From the docking study, noroxyhydrastatine was observed to have better binding affinity in comparison to chloroquine. The binding of noroxyhydrastinine with dihydroorotate dehydrogenase was further validated by molecular dynamics simulation and was observed to be significantly stable in comparison to the co-crystal inhibitor. During simulations it was observed that noroxyhydrastinine retained the interactions, giving strong indications of its effectiveness against the P. falciparum proteins and stability in the binding pocket. From the Density-functional theory analysis, the band gap energy of noroxyhydrastinine was found to be 0.186 Ha indicating a favourable interaction. Conclusion: The in silico analysis as an addition to the in vitro results provide strong evidence of noroxyhydrastinine as an anti malarial agent.

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