scholarly journals Probing the Structural Basis of Citrus Phytochrome B using Computational Modelling and Molecular Dynamics Simulation Approaches

2021 ◽  
Author(s):  
Muhammad Tahir ul Qamar ◽  
Muhammad Usman Mirza ◽  
Jia-Ming Song ◽  
Muhammad Junaid Rao ◽  
Xi-Tong Zhu ◽  
...  
Keyword(s):  
Md Simulation ◽  
Red Light ◽  
3D Structure ◽  
Computational Modelling ◽  
Structural Difference ◽  
Dynamics Simulation ◽  
Structural Basis ◽  
Functional Implications ◽  
Domain Organisation ◽  
Photosynthetic Potential

Phytochromes are known as red/far-red light photoreceptors and responsible for directing the photosensory responses across the species. Such responses majorly include photosynthetic potential and pigmentation in bacteria, whereas in a plant, they are involved in chloroplast development and photomorphogenesis. Many prokaryotic Phys have been modelled for their structural/functional analysis, but their plant counterparts have not been explored yet. To date, only the crystal structures of the photo-sensing module of PhyB isoform from Arabidopsis and Glycine have been resolved experimentally. Thus, in this study, we elucidated the complete 3D structure of Citrus PhyB. Initially, the structure and organisation of the Citrus PhyB have been predicted computationally, which were found to have the same domain organisation as A.thaliana and G.max PhyBs, yet their considerable distinct structural difference indicated potential divergence in signaling/functioning. Therefore, to evaluate the structural and functional implications of Citrus PhyB, we compared its structure with A. thaliana and G. max PhyBs using MD simulation. The modeling studies revealed that the region of Citrus PhyB-GAF domain possibly contributes to the variations. Hence, structural/molecular insights into Citrus PhyB can help to discover the Phys signaling and thus, an essential framework can be designed for optogenetic reagents and various agricultural benefits.

scholarly journals Detailed Analysis of 17β-Estradiol-Aptamer InteractionsAptamer Interactions: A Molecular Dynamics Simulation Study

2018 ◽  
Author(s):  
Alexander Eisold ◽  
Dirk Labudde
Keyword(s):  
Md Simulation ◽  
3D Structure ◽  
Dynamics Simulation ◽  
Coarse Grained ◽  
Negative Effects ◽  
Time Step ◽  
Binding Characteristics ◽  
Structure Information ◽  
Potential Binding ◽  
Interior Loop

Micro-pollutants such as 17β-Estradiol (E2) have been detected in different water resources and their negative effects on the environment and organisms have been observed. Aptamers are established as a possible detection tool, but the underlying ligand binding is largely unexplored. In this study, a previously described 35-mer E2-specific aptamer was used to analyse the binding characteristics between E2 and the aptamer with a MD simulation in an aqueous medium. Because there is no 3D structure information available for this aptamer, it was modeled using coarse-grained modeling method. The E2 ligand was positioned inside a potential binding area of the predicted aptamer structure, the complex was used for an 25 ns MD simulation, and the interactions were examined for each time step. We identified E2-specific bases within the interior loop of the aptamer and also demonstrated the influence of frequently underestimated water-mediated hydrogen bonds. The study contributes to the understanding of the behavior of ligands binding with aptamer structure in an aqueous solution. The developed workflow allows generating and examining further appealing ligand-aptamer complexes.

scholarly journals Probing the Structural Basis of Citrus Phytochrome B using Computational Modelling and Molecular Dynamics Simulation Approaches

2021 ◽  
pp. 116895
Author(s):  
Muhammad Tahir ul Qamar ◽  
Muhammad Usman Mirza ◽  
Jia-Ming Song ◽  
Muhammad Junaid Rao ◽  
Xitong Zhu ◽  
...  
Keyword(s):  
Molecular Dynamics ◽  
Molecular Dynamics Simulation ◽  
Computational Modelling ◽  
Dynamics Simulation ◽  
Structural Basis ◽  
Phytochrome B

MODELING OF THREE DIMENSIONAL STRUCTURE OF HUMAN ALPHA-FETOPROTEIN COMPLEXED WITH DIETHYLSTILBESTROL: DOCKING AND MOLECULAR DYNAMICS SIMULATION STUDY

2012 ◽  
Vol 10 (02) ◽  
pp. 1241012 ◽  
Author(s):  
ALEXANDER A. TERENTIEV ◽  
NURBUBU T. MOLDOGAZIEVA ◽  
OLGA V. LEVTSOVA ◽  
DMITRY M. MAXIMENKO ◽  
DENIS A. BOROZDENKO ◽  
...  
Keyword(s):  
Molecular Dynamics ◽  
Binding Site ◽  
Simulation Study ◽  
Md Simulation ◽  
Hydrophobic Interactions ◽  
3D Structure ◽  
Three Dimensional ◽  
Alpha Fetoprotein ◽  
Dynamics Simulation ◽  
Dimensional Structure

It has been long experimentally demonstrated that human alpha-fetoprotein (HAFP) has an ability to bind immobilized estrogens with the most efficiency for synthetic estrogen analog — diethylstilbestrol (DES). However, the question remains why the human AFP (HAFP), unlike rodent AFP, cannot bind free estrogens. Moreover, despite the fact that AFP was first discovered more than 50 years ago and is presently recognized as a "golden standard" among onco-biomarkers, its three-dimensional (3D) structure has not been experimentally solved yet. In this work using MODELLER program, we generated 3D model of HAFP on the basis of homology with human serum albumin (HSA) and Vitamin D–binding protein (VTDB) with subsequent molecular docking of DES to the model structure and molecular dynamics (MD) simulation study of the complex obtained. The model constructed has U-shaped structure in which a cavity may be distinguished. In this cavity the putative estrogen-binding site is localized. Validation by RMSD calculation and with the use of PROCHECK program showed good quality of the model and stability of extended region of four alpha-helical structures that contains putative hormone-binding residues. Data extracted from MD simulation trajectory allow proposing two types of interactions between amino acid residues of HAFP and DES molecule: (1) hydrogen bonding with involvement of residues S445, R452, and E551; (2) hydrophobic interactions with participation of L138, M448, and M548 residues. A suggestion is made that immobilization of the hormone using a long spacer provides delivery of the estrogen molecule to the binding site and, thereby, facilitates interaction between HAFP and the hormone.

Structural Insights into the IL12:IL12 Receptor Complex Assembly by Molecular Modeling, Docking, and Molecular Dynamics Simulation

2020 ◽  
Vol 23 ◽  
Author(s):  
Sakshi Singh ◽  
Geeta Rai
Keyword(s):  
Structure Prediction ◽  
Md Simulation ◽  
De Novo ◽  
3D Structure ◽  
Computational Method ◽  
Dynamics Simulation ◽  
Hematopoietic Progenitor Cell ◽  
Interleukin 12 ◽  
Type I ◽  
Progenitor Cell Proliferation

Background: Interleukin-12 receptor (IL12R) is a type I cytokine receptor that can promote hematopoiesis and regulate innate and adaptive immunity. It binds with the IL12 ligand, which activates the IL-12 signaling pathway that triggers hematopoietic progenitor cell proliferation and differentiation process. The structure of IL12:IL12R complex is not known. Objective: The present work describes a de novo computational method for rational protein designing to elucidate the structure of IL12:IL12R complex. Methods: Homology modeling, docking, and MD simulation methods were used to design mimics of the interaction of IL12 and IL12R. Results: 3D structure prediction and validation confirms the accurate structure of IL12R protein that contains immunoglobin domain, fibronectin type three domain, cytokine-binding domain, and WSXWS motif. Molecular docking and MD simulation revealed that IL12R bound tightly with IL12 ligand at their interface. The estimated binding energy of the docked complex was -26.7 kcal/mol, and the interface area was 281.4 Å2. Hotspot prediction suggested that ARG34, SER58, GLU61, CYS62, LEU63, SER73, ASP142, GLN146, LYS168, THR169 ARG181, ARG183, ARG189, and TYR193 residues in IL12 ligand interacted with SER175, ALA176, CYS177, PRO178, ALA179, ALA180, GLU181, GLU182, ALA192, VAL193, HIS194, ARG208, TYR246, GLN289, ASP290, ARG291, TYR292, TYR293 and SER294 residues in IL12 receptor. Conclusion: The results of the study provides a simulated molecular structure of IL12:IL12R complex that could offer a promising target complex to substantiate IL12 based drug-designing approaches.

Towards red-light o-carborane derivatives with both aggregation induced emission and thermally activated delayed fluorescence combining quantum chemistry calculation with molecular dynamics simulation

2019 ◽  
Vol 7 (9) ◽  
pp. 2699-2709 ◽  
Author(s):  
Ying-Chen Duan ◽  
Ying Gao ◽  
Yun Geng ◽  
Yong Wu ◽  
Guo-Gang Shan ◽  
...  
Keyword(s):  
Molecular Dynamics ◽  
Molecular Dynamics Simulation ◽  
Md Simulation ◽  
Red Light ◽  
Delayed Fluorescence ◽  
Dynamics Simulation ◽  
Quantum Chemistry Calculation ◽  
Thermally Activated Delayed Fluorescence ◽  
Thermally Activated ◽  
Chemistry Calculation

We investigated a series of o-carborane derivatives and designed new red-light derivatives by combining DFT with MD simulation. The reason of their TADF was explored and the AIE property was analyzed in water, crystal and film surroundings.

scholarly journals Detailed Analysis of 17β-Estradiol-Aptamer Interactions – A Molecular Dynamics Simulation Study

2018 ◽  
Author(s):  
Alexander Eisold ◽  
Dirk Labudde
Keyword(s):  
Md Simulation ◽  
3D Structure ◽  
Dynamics Simulation ◽  
Coarse Grained ◽  
Negative Effects ◽  
Time Step ◽  
Binding Characteristics ◽  
Structure Information ◽  
Low Concentrations ◽  
Interior Loop

Micro pollutants such as 17β-Estradiol (E2) have been detected in low concentrations in different water resources and their negative effects on the environment and organisms are observed. In this study, a previously described 35-mer E2-specific aptamer was used to investigate the underlying binding characteristics between E2 and the aptamer through an MD simulation in an aqueous medium. There is no 3D structure information for this aptamer, so it was modeled using coarse-grained modeling method. The E2 ligand was positioned inside the potential binding area of the aptamer structure, the underlying complex was used for an 25 ns MD simulation, and the interactions were examined by an interaction profiler tool for each time step. The E2-specific bases of the aptamer had presumably dominant roles in the binding of E2 in terms of the different interaction types. We identified the specific bases within the interior loop of the aptamer and we also demonstrate the influence of oftentimes underestimated water-mediated hydrogen bonds. The study contributes to the understanding of the behavior of ligands binding through aptamer structure in an aqueous solution. The developed workflow allows to generate and examine further appealing ligand aptamer complexes.

Structure prediction of SPAK C-terminal domain and analysis of its binding to RFXV/I motifs by homology modelling, docking, and molecular dynamics simulation studies

2020 ◽  
Vol 16 ◽  
Author(s):  
Mubarak A. Alamri ◽  
Ahmed D. Alafnan ◽  
Obaid Afzal ◽  
Alhumaidi B. Alabbas ◽  
Safar M. Alqahtani
Keyword(s):  
Molecular Dynamic ◽  
Dynamic Stability ◽  
Md Simulation ◽  
Homology Modelling ◽  
Antihypertensive Agents ◽  
Structure And Function ◽  
Dynamics Simulation ◽  
Dimensional Structure ◽  
Terminal Domain ◽  
And Function

Background: The STE20/SPS1-related proline/alanine-rich kinase (SPAK) is a component of WNKSPAK/OSR1 signaling pathway that plays an essential role in blood pressure regulation. The function of SPAK is mediated by its highly conserved C-terminal domain (CTD) that interacts with RFXV/I motifs of upstream activators, WNK kinases, and downstream substrate, cation-chloride cotransporters. Objective: To determine and validate the three-dimensional structure of the CTD of SPAK and to study and analyze its interaction with the RFXV/I motifs. Methods: A homology model of SPAK CTD was generated and validated through multiple approaches. The model was based on utilizing the OSR1 protein kinase as a template. This model was subjected to 100 ns molecular dynamic (MD) simulation to evaluate its dynamic stability. The final equilibrated model was used to dock the RFQV-peptide derived from WNK4 into the primary pocket that was determined based on the homology sequence between human SPAK and OSR1 CTDs. The mechanism of interaction, conformational rearrangement and dynamic stability of the binding of RFQV-peptide to SPAK CTD were characterized by molecular docking and molecular dynamic simulation. Results: The MD simulation suggested that the binding of RFQV induces a large conformational change due to the distribution of salt bridge within the loop regions. These results may help in understanding the relation between the structure and function of SPAK CTD and to support drug design of potential SPAK kinase inhibitors as antihypertensive agents. Conclusion: This study provides deep insight into SPAK CTD structure and function relationship.

scholarly journals Molecular dynamics simulation of sI methane hydrate under compression and tension

2020 ◽  
Vol 18 (1) ◽  
pp. 69-76
Author(s):  
Qiang Wang ◽  
Qizhong Tang ◽  
Sen Tian
Keyword(s):  
Molecular Dynamics ◽  
Methane Hydrate ◽  
Fracture Process ◽  
Md Simulation ◽  
Maximum Stress ◽  
Dynamics Simulation ◽  
Tensile Fracture ◽  
Maximum Compressive Stress ◽  
Motion State ◽  
Stress States

AbstractMolecular dynamics (MD) analysis of methane hydrate is important for the application of methane hydrate technology. This study investigated the microstructure changes of sI methane hydrate and the laws of stress–strain evolution under the condition of compression and tension by using MD simulation. This study further explored the mechanical property and stability of sI methane hydrate under different stress states. Results showed that tensile and compressive failures produced an obvious size effect under a certain condition. At low temperature and high pressure, most of the clathrate hydrate maintained a stable structure in the tensile fracture process, during which only a small amount of unstable methane broke the structure, thereby, presenting a free-motion state. The methane hydrate cracked when the system reached the maximum stress in the loading process, in which the maximum compressive stress is larger than the tensile stress under the same experimental condition. This study provides a basis for understanding the microscopic stress characteristics of methane hydrate.

scholarly journals Modeling and Molecular Dynamics of the 3D Structure of the HPV16 E7 Protein and Its Variants

2021 ◽  
Vol 22 (3) ◽  
pp. 1400
Author(s):  
Ciresthel Bello-Rios ◽  
Sarita Montaño ◽  
Olga Lilia Garibay-Cerdenares ◽  
Lilian Esmeralda Araujo-Arcos ◽  
Marco Antonio Leyva-Vázquez ◽  
...  
Keyword(s):  
Molecular Dynamics ◽  
3D Structure ◽  
Epidemiological Studies ◽  
Dynamics Simulation ◽  
Structural Refinement ◽  
Oncogenic Potential ◽  
Structural Differences ◽  
Reference Protein ◽  
E6 And E7 ◽  
First Time

The oncogenic potential of high-risk human papillomavirus (HPV) is predicated on the production of the E6 and E7 oncoproteins, which are responsible for disrupting the control of the cell cycle. Epidemiological studies have proposed that the presence of the N29S and H51N variants of the HPV16 E7 protein is significantly associated with cervical cancer. It has been suggested that changes in the amino acid sequence of E7 variants may affect the oncoprotein 3D structure; however, this remains uncertain. An analysis of the structural differences of the HPV16 E7 protein and its variants (N29S and H51N) was performed through homology modeling and structural refinement by molecular dynamics simulation. We propose, for the first time, a 3D structure of the E7 reference protein and two of Its variants (N29S and H51N), and conclude that the mutations induced by the variants in N29S and H51N have a significant influence on the 3D structure of the E7 protein of HPV16, which could be related to the oncogenic capacity of this protein.

scholarly journals Identification of fidelity-governing factors in human recombinases DMC1 and RAD51 from cryo-EM structures

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Shih-Chi Luo ◽  
Hsin-Yi Yeh ◽  
Wei-Hsuan Lan ◽  
Yi-Min Wu ◽  
Cheng-Han Yang ◽  
...  
Keyword(s):  
Functional Analysis ◽  
Structural Analysis ◽  
Md Simulation ◽  
Structural Basis ◽  
High Fidelity ◽  
Dna Dynamics ◽  
Genomic Integrity ◽  
Mismatched Dna ◽  
Dna Backbone ◽  
Loop 2

AbstractBoth high-fidelity and mismatch-tolerant recombination, catalyzed by RAD51 and DMC1 recombinases, respectively, are indispensable for genomic integrity. Here, we use cryo-EM, MD simulation and functional analysis to elucidate the structural basis for the mismatch tolerance of DMC1. Structural analysis of DMC1 presynaptic and postsynaptic complexes suggested that the lineage-specific Loop 1 Gln244 (Met243 in RAD51) may help stabilize DNA backbone, whereas Loop 2 Pro274 and Gly275 (Val273/Asp274 in RAD51) may provide an open “triplet gate” for mismatch tolerance. In support, DMC1-Q244M displayed marked increase in DNA dynamics, leading to unobservable DNA map. MD simulation showed highly dispersive mismatched DNA ensemble in RAD51 but well-converged DNA in DMC1 and RAD51-V273P/D274G. Replacing Loop 1 or Loop 2 residues in DMC1 with RAD51 counterparts enhanced DMC1 fidelity, while reciprocal mutations in RAD51 attenuated its fidelity. Our results show that three Loop 1/Loop 2 residues jointly enact contrasting fidelities of DNA recombinases.

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