Functional characterization and structural modelling of peptidoglycan degrading β-N-acetyl-glucosaminidase from a dental isolate of Serratia marcescens

2020 ◽  
Vol 23 ◽  
Author(s):  
Aditi Rathee ◽  
Anil Panwar ◽  
Seema Kumari ◽  
Sanjay Chhibber ◽  
Ashok Kumar
Keyword(s):  
Functional Characterization ◽  
Major Change ◽  
Crystal Form ◽  
Bound State ◽  
Dynamics Simulation ◽  
Gram Positive ◽  
Structural Cell ◽  
Stability Structure ◽  
Arginine Residues ◽  
The Stability

Introduction:: Enzymatic degradation of peptidoglycan, a structural cell wall component of Gram-positive bacteria, has attracted considerable attention being a specific target for many known antibiotics. Methods:: Peptidoglycan hydrolases are involved in bacterial lysis through peptidoglycan degradation. β-N-acetylglucosaminidase, a peptidoglycan hydrolase, acts on O-glycosidic bonds formed by N-acetylglucosamine and N-acetyl muramic acid residues of peptidoglycan. Aim of present study was to study the action of β-N-acetylglucosaminidase, on methicillin- resistant Staphylococcus aureus (MRSA) and other Gram-negative bacteria. Results:: We investigated its dynamic behaviour using molecular dynamics simulation and observed that serine and alanine residues are involved in catalytic reaction in addition to aspartic acid, histidine, lysine and arginine residues. When simulated in its bound state, the RMSD values were found lesser than crystal form in the time stamp of 1000 picoseconds revealing its stability. Structure remained stably folded over 1000 picoseconds without undergoing any major change further confirming the stability of complex. Conclusion:: It can be concluded that enzymes belonging to this category can serve as a tool in eradicating Gram-positive pathogens and associated infections.

scholarly journals Rational thermostabilisation of four-helix bundle dimeric de novo proteins

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Shin Irumagawa ◽  
Kaito Kobayashi ◽  
Yutaka Saito ◽  
Takeshi Miyata ◽  
Mitsuo Umetsu ◽  
...  
Keyword(s):  
Protein Design ◽  
De Novo ◽  
Protein Complexes ◽  
Salt Bridge ◽  
Dynamics Simulation ◽  
Saturation Mutagenesis ◽  
Helix Bundle ◽  
Stable Mutant ◽  
Four Helix Bundle ◽  
The Stability

AbstractThe stability of proteins is an important factor for industrial and medical applications. Improving protein stability is one of the main subjects in protein engineering. In a previous study, we improved the stability of a four-helix bundle dimeric de novo protein (WA20) by five mutations. The stabilised mutant (H26L/G28S/N34L/V71L/E78L, SUWA) showed an extremely high denaturation midpoint temperature (Tm). Although SUWA is a remarkably hyperstable protein, in protein design and engineering, it is an attractive challenge to rationally explore more stable mutants. In this study, we predicted stabilising mutations of WA20 by in silico saturation mutagenesis and molecular dynamics simulation, and experimentally confirmed three stabilising mutations of WA20 (N22A, N22E, and H86K). The stability of a double mutant (N22A/H86K, rationally optimised WA20, ROWA) was greatly improved compared with WA20 (ΔTm = 10.6 °C). The model structures suggested that N22A enhances the stability of the α-helices and N22E and H86K contribute to salt-bridge formation for protein stabilisation. These mutations were also added to SUWA and improved its Tm. Remarkably, the most stable mutant of SUWA (N22E/H86K, rationally optimised SUWA, ROSA) showed the highest Tm (129.0 °C). These new thermostable mutants will be useful as a component of protein nanobuilding blocks to construct supramolecular protein complexes.

scholarly journals Molecular Dynamics Simulation of the Interaction of Two Linear Battacin Analogs with Model Gram-Positive and Gram-Negative Bacterial Cell Membranes

ACS Omega ◽  
2020 ◽  
Author(s):  
Aparajita Chakraborty ◽  
Elisey Kobzev ◽  
Jonathan Chan ◽  
Gayan Heruka de Zoysa ◽  
Vijayalekshmi Sarojini ◽  
...  
Keyword(s):  
Molecular Dynamics ◽  
Molecular Dynamics Simulation ◽  
Bacterial Cell ◽  
Cell Membranes ◽  
Dynamics Simulation ◽  
Gram Positive ◽  
Gram Negative

scholarly journals Prediction of Functional Consequences of Missense Mutations in ANO4 Gene

2021 ◽  
Vol 22 (5) ◽  
pp. 2732
Author(s):  
Nadine Reichhart ◽  
Vladimir M. Milenkovic ◽  
Christian H. Wetzel ◽  
Olaf Strauß
Keyword(s):  
Transmembrane Protein ◽  
Functional Characterization ◽  
Missense Mutations ◽  
Mutant Proteins ◽  
Functional Consequences ◽  
New Perspective ◽  
The Stability ◽  
Dynamics Simulations ◽  
And Function

The anoctamin (TMEM16) family of transmembrane protein consists of ten members in vertebrates, which act as Ca2+-dependent ion channels and/or Ca2+-dependent scramblases. ANO4 which is primarily expressed in the CNS and certain endocrine glands, has been associated with various neuronal disorders. Therefore, we focused our study on prioritizing missense mutations that are assumed to alter the structure and stability of ANO4 protein. We employed a wide array of evolution and structure based in silico prediction methods to identify potentially deleterious missense mutations in the ANO4 gene. Identified pathogenic mutations were then mapped to the modeled human ANO4 structure and the effects of missense mutations were studied on the atomic level using molecular dynamics simulations. Our data show that the G80A and A500T mutations significantly alter the stability of the mutant proteins, thus providing new perspective on the role of missense mutations in ANO4 gene. Results obtained in this study may help to identify disease associated mutations which affect ANO4 protein structure and function and might facilitate future functional characterization of ANO4.

scholarly journals Treatment of Rheumatoid Arthritis with Traditional Chinese Medicine

2014 ◽  
Vol 2014 ◽  
pp. 1-11 ◽  
Author(s):  
Wen-Yuan Lee ◽  
Hsin-Yi Chen ◽  
Kuan-Chung Chen ◽  
Calvin Yu-Chian Chen
Keyword(s):  
Rheumatoid Arthritis ◽  
Chinese Medicine ◽  
Traditional Chinese Medicine ◽  
Protein Complex ◽  
Chronic Inflammatory Disease ◽  
Dynamics Simulation ◽  
Current Therapy ◽  
Potential Candidate ◽  
Interleukin 6 Receptor ◽  
The Stability

Rheumatoid arthritis (RA) is a chronic inflammatory disease that will affect quality of life and, working efficiency, and produce negative thoughts for patients. Current therapy of RA is treated with disease-modifying antirheumatic drugs (DMARDs). Although most of these treatment methods are effective, most patients still have a pleasant experience either due to poor efficacy or side effects or both. Interleukin-6 receptor (IL6R) is important in the pathogenesis of RA. In this study, we would like to detect the potential candidates which inhibit IL6R against RA from traditional Chinese medicine (TCM). We use TCM compounds from the TCM Database@Taiwan for virtually screening the potential IL6R inhibitors. The TCM candidate compound, calycosin, has potent binding affinity with IL6R protein. The molecular dynamics simulation was employed to validate the stability of interaction in the protein complex with calycosin. The analysis indicates that protein complex with calycosin is more stable. In addition, calycosin is known to be one of the components ofAngelica sinensis, which has been indicated to have an important role in the treatment of rheumatoid arthritis. Therefore, calycosin is a potential candidate as lead compounds for further study in drug development process with IL6R protein against rheumatoid arthritis.

Virtual Screening of Phyto Chemicals Against SARS-CoV-2 Targets

2021 ◽  
Vol 6 (3) ◽  
pp. 61-76
Author(s):  
Shahanas Naisam ◽  
Vidhya V. S. ◽  
Suvanish Kumar ◽  
Nidhin Sreekumar
Keyword(s):  
Dynamics Simulation ◽  
Spike Protein ◽  
Ligand Interaction ◽  
Docking Analysis ◽  
Drug Molecules ◽  
In Vivo Analysis ◽  
Protein Ligand Interaction ◽  
The Stability ◽  
3Cl Protease

The COVID-19 pandemic wave has recommenced and is spreading like wildfire across the globe. The well-reported antiviral potency of phyto compounds could offer potential drug molecules for the current predicament. The present study analyses the molecular interaction of selected phyto compounds and SARS-CoV-2 molecular target proteins, namely spike protein, RNA-dependent RNA polymerase, 3C-like proteases, and papain-like protease. Ten newly modeled ligands were also considered for the study. Molecular docking analysis was carried out independently using MOE, AutoDock Vina, Schrodinger-Glide, and the stability of protein-ligand interaction was validated through molecular dynamics simulation. Petunidin interacts with spike protein resulting in a good Gscore, binding energy, and H-bond interaction. Also, alions, letestuianin-A, (+)-pinitol show better interaction with RdRp, 3CL-protease, and papain-like protease, respectively. The presented work screens through 2314 ligands to yield top-ranked molecules which could be taken up to develop potential lead molecules via in-vivo analysis.

scholarly journals Study of Caspase 8 Inhibition for the Management of Alzheimer’s Disease: A Molecular Docking and Dynamics Simulation

Molecules ◽  
2020 ◽  
Vol 25 (9) ◽  
pp. 2071
Author(s):  
Syed Sayeed Ahmad ◽  
Meetali Sinha ◽  
Khurshid Ahmad ◽  
Mohammad Khalid ◽  
Inho Choi
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Molecular Docking ◽  
Md Simulation ◽  
Simulation Analysis ◽  
Dynamics Simulation ◽  
Caspase 8 ◽  
Amino Acid Residues ◽  
The Stability ◽  
Molecular Docking And Dynamics

Alzheimer’s disease (AD) is the most common type of dementia and usually manifests as diminished episodic memory and cognitive functions. Caspases are crucial mediators of neuronal death in a number of neurodegenerative diseases, and caspase 8 is considered a major therapeutic target in the context of AD. In the present study, we performed a virtual screening of 200 natural compounds by molecular docking with respect to their abilities to bind with caspase 8. Among them, rutaecarpine was found to have the highest (negative) binding energy (−6.5 kcal/mol) and was further subjected to molecular dynamics (MD) simulation analysis. Caspase 8 was determined to interact with rutaecarpine through five amino acid residues, specifically Thr337, Lys353, Val354, Phe355, and Phe356, and two hydrogen bonds (ligand: H35-A: LYS353:O and A:PHE355: N-ligand: N5). Furthermore, a 50 ns MD simulation was conducted to optimize the interaction, to predict complex flexibility, and to investigate the stability of the caspase 8–rutaecarpine complex, which appeared to be quite stable. The obtained results propose that rutaecarpine could be a lead compound that bears remarkable anti-Alzheimer’s potential against caspase 8.

On the stability of a dipole-bound state in the presence of a molecule

2019 ◽  
Vol 21 (44) ◽  
pp. 24286-24290 ◽  
Author(s):  
Maria Elena Castellani ◽  
Cate S. Anstöter ◽  
Jan R. R. Verlet
Keyword(s):  
Alkyl Chain ◽  
Bound State ◽  
The Stability

A dipole-bound state is found to survive despite its disruption by an alkyl chain.

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