scholarly journals POTENSI SENYAWA BIOAKTIF TANAMAN GENUS Phyllanthus SEBAGAI INHIBITOR REPLIKASI VIRUS HEPATITIS B

2017 ◽  
Vol 4 (2) ◽  
pp. 85
Author(s):  
. Firdayani ◽  
Susi Kusumaningrum ◽  
Yosephine Ria Miranti
Keyword(s):  
Molecular Docking ◽  
Amino Acid ◽  
Hepatitis B ◽  
Protein Data Bank ◽  
Bioactive Compounds ◽  
Core Protein ◽  
Data Bank ◽  
Amino Acid Residues ◽  
Virus Hepatitis ◽  
Molegro Virtual Docker

Potency of Plant Bioactive Compounds from the Genus Phyllanthus as Hepatitis B Virus Replication InhibitorIn this research, simulations of molecular docking of Phyllanthus bioactive compounds were performed into the core protein of HBV. This simulation aimed to predict the interaction between compounds with virus core protein causing disruption of capsid formation and inhibiting its replication. The docking simulation was completed by Molegro Virtual Docker 6.0. The 3D stable conformation of molecule structures were docked into HBV core protein downloaded from Protein Data Bank, then the results were analyzed to view the minimum energy and interactions that occurred. The coordinate docking was done at the same coordinate as the previously docked reference ligand position and was validated. From the results it was known that repandusinic acid formed the most stable affinity bond with amino acid residues of viral core proteins. Interaction of B chain forming hydrogen bonds with the amino acid residues of Thr 33, Trp 102, Phe 23, Leu 140, Tyr 118 and Ser 141, and C chain with Thr 128, Val 124 and Glu 117.These compounds can be used as marker for anti HBV.Keyword: Bioactive compounds, core protein, HBV , molecular docking, Phyllanthus ABSTRAKPada penelitian ini dilakukan simulasi penambatan molekul senyawa-senyawa bioaktif Phyllanthus ke dalam protein inti virus hepatitis B. Simulasi ini bertujuan untuk memprediksi interaksi terbentuk antara senyawa dengan protein yang menyebabkan terganggunya pembentukan kapsid virus dan menghambat replikasinya. Simulasi penambatan molekul dilakukan menggunakan program Molegro Virtual Docker 6.0. Sebagai reseptor target digunakan struktur 3D protein inti yang diunduh dari Protein Data Bank. Posisi penambatan dilakukan pada koordinat yang sama dengan posisi ligan referensi yang sudah tertambat sebelumnya dan tervalidasi. Dari hasil simulasi diketahui bahwa asam repandusinat membentuk komplek dengan energi afinitas ikatan yang paling kecil dengan residu asam amino protein inti virus. Interaksi terjadi dengan rantai B yang membentuk ikatan hidrogen dengan asam amino Thr 33, Trp 102, Phe 23, Leu 140, Tyr 118 dan Ser 141, dan rantai C dengan asam amino Thr 128, Val 124 dan Glu 117. Senyawa ini dapat dijadikan sebagai marka untuk anti VHB.Kata kunci: Penambatan molekul, Phyllanthus, protein inti, senyawa bioaktif, VHBReceived: 11 December 2017                 Accepted: 27 December 2017           Published: 31 December 2017 

scholarly journals Amino acid residues at core protein dimer-dimer interface modulate multiple steps of hepatitis B virus replication and HBeAg biogenesis

2021 ◽  
Vol 17 (11) ◽  
pp. e1010057
Author(s):  
Hui Liu ◽  
Junjun Cheng ◽  
Usha Viswanathan ◽  
Jinhong Chang ◽  
Fengmin Lu ◽  
...  
Keyword(s):  
Amino Acid ◽  
Hepatitis B Virus ◽  
Hepatitis B ◽  
Core Protein ◽  
Amino Acid Residues ◽  
Viral Dna ◽  
Viral Dna Replication ◽  
Dimer Interface ◽  
Rich Domain ◽  
B Virus

The core protein (Cp) of hepatitis B virus (HBV) assembles pregenomic RNA (pgRNA) and viral DNA polymerase to form nucleocapsids where the reverse transcriptional viral DNA replication takes place. Core protein allosteric modulators (CpAMs) inhibit HBV replication by binding to a hydrophobic “HAP” pocket at Cp dimer-dimer interfaces to misdirect the assembly of Cp dimers into aberrant or morphologically “normal” capsids devoid of pgRNA. We report herein that a panel of CpAM-resistant Cp with single amino acid substitution of residues at the dimer-dimer interface not only disrupted pgRNA packaging, but also compromised nucleocapsid envelopment, virion infectivity and covalently closed circular (ccc) DNA biosynthesis. Interestingly, these mutations also significantly reduced the secretion of HBeAg. Biochemical analysis revealed that the CpAM-resistant mutations in the context of precore protein (p25) did not affect the levels of p22 produced by signal peptidase removal of N-terminal 19 amino acid residues, but significantly reduced p17, which is produced by furin cleavage of C-terminal arginine-rich domain of p22 and secreted as HBeAg. Interestingly, p22 existed as both unphosphorylated and phosphorylated forms. While the unphosphorylated p22 is in the membranous secretary organelles and the precursor of HBeAg, p22 in the cytosol and nuclei is hyperphosphorylated at the C-terminal arginine-rich domain and interacts with Cp to disrupt capsid assembly and viral DNA replication. The results thus indicate that in addition to nucleocapsid assembly, interaction of Cp at dimer-dimer interface also plays important roles in the production and infectivity of progeny virions through modulation of nucleocapsid envelopment and uncoating. Similar interaction at reduced p17 dimer-dimer interface appears to be important for its metabolic stability and sensitivity to CpAM suppression of HBeAg secretion.

scholarly journals Making glycoproteins a little bit sweeter withPDB-REDO

2018 ◽  
Vol 74 (8) ◽  
pp. 463-472 ◽  
Author(s):  
Bart van Beusekom ◽  
Thomas Lütteke ◽  
Robbie P. Joosten
Keyword(s):  
Experimental Data ◽  
Amino Acid ◽  
Protein Data Bank ◽  
Model Building ◽  
Data Bank ◽  
Structure Model ◽  
Amino Acid Residues ◽  
Post Translational Modification ◽  
High Quality ◽  
Glycoprotein Structure

Glycosylation is one of the most common forms of protein post-translational modification, but is also the most complex. Dealing with glycoproteins in structure model building, refinement, validation and PDB deposition is more error-prone than dealing with nonglycosylated proteins owing to limitations of the experimental data and available software tools. Also, experimentalists are typically less experienced in dealing with carbohydrate residues than with amino-acid residues. The results of the reannotation and re-refinement byPDB-REDOof 8114 glycoprotein structure models from the Protein Data Bank are analyzed. The positive aspects of 3620 reannotations and subsequent refinement, as well as the remaining challenges to obtaining consistently high-quality carbohydrate models, are discussed.

scholarly journals GC-MS- and NMR-Based Metabolomics and Molecular Docking Reveal the Potential Alpha-Glucosidase Inhibitors from Psychotria malayana Jack Leaves

2021 ◽  
Vol 14 (10) ◽  
pp. 978
Author(s):  
Tanzina Sharmin Nipun ◽  
Alfi Khatib ◽  
Zalikha Ibrahim ◽  
Qamar Uddin Ahmed ◽  
Irna Elina Redzwan ◽  
...  
Keyword(s):  
Molecular Docking ◽  
Amino Acid ◽  
Bioactive Compounds ◽  
In Silico ◽  
Partial Least Square ◽  
Least Square ◽  
Amino Acid Residues ◽  
Phytochemical Study ◽  
Glucosidase Inhibitors ◽  
Alpha Glucosidase

Psychotria malayana Jack leaf, known in Indonesia as “daun salung”, is traditionally used for the treatment of diabetes and other diseases. Despite its potential, the phytochemical study related to its anti-diabetic activity is still lacking. Thus, this study aimed to identify putative inhibitors of α-glucosidase, a prominent enzyme contributing to diabetes type 2 in P. malayana leaf extract using gas chromatography-mass spectrometry (GC-MS)- and nuclear magnetic resonance (NMR)-based metabolomics, and to investigate the molecular interaction between those inhibitors and the enzyme through in silico approach. Twenty samples were extracted with different solvent ratios of methanol–water (0, 25, 50, 75, and 100% v/v). All extracts were tested on the alpha-glucosidase inhibition (AGI) assay and analyzed using GC-MS and NMR. Multivariate data analysis through a partial least square (PLS) and orthogonal partial square (OPLS) models were developed in order to correlate the metabolite profile and the bioactivity leading to the annotation of the putative bioactive compounds in the plant extracts. A total of ten putative bioactive compounds were identified and some of them reported in this plant for the first time, namely 1,3,5-benzenetriol (1); palmitic acid (2); cholesta-7,9(11)-diene-3-ol (3); 1-monopalmitin (4); β-tocopherol (5); α-tocopherol (6); 24-epicampesterol (7); stigmast-5-ene (8); 4-hydroxyphenylpyruvic acid (10); and glutamine (11). For the evaluation of the potential binding modes between the inhibitors and protein, the in silico study via molecular docking was performed where the crystal structure of Saccharomyces cerevisiae isomaltase (PDB code: 3A4A) was used. Ten amino acid residues, namely ASP352, HIE351, GLN182, ARG442, ASH215, SER311, ARG213, GLH277, GLN279, and PRO312 established hydrogen bond in the docked complex, as well as hydrophobic interaction of other amino acid residues with the putative compounds. The α-glucosidase inhibitors showed moderate to high binding affinities (−5.5 to −9.4 kcal/mol) towards the active site of the enzymatic protein, where compounds 3, 5, and 8 showed higher binding affinity compared to both quercetin and control ligand.

scholarly journals Virtual Screening: Prediksi potensi 8-shogaol terhadap c-Jun N-Terminal Kinase (JNK)

2020 ◽  
Vol 4 (1) ◽  
pp. 1 ◽  
Author(s):  
Yohanes Bare ◽  
Mansur S ◽  
Sri Sulystyaningsih Natalia Daeng Tiring ◽  
Dewi Ratih Tirto Sari ◽  
Andri Maulidi
Keyword(s):  
Hydrogen Bond ◽  
Amino Acid ◽  
Virtual Screening ◽  
Protein Data Bank ◽  
Van Der Waals ◽  
Data Bank ◽  
Software Visualization ◽  
Amino Acid Residues ◽  
Discovery Studio ◽  
Protein Model

JNK adalah gen yang berperan dalam metabolisme DMT2. Dalam pengobatan T2DM digunakan JNK sebagai potensi terapi dengan menggunakan bahan alam. 8-shogaol adalah komponen kimia yang terkandung dalam jahe yang memiliki aktivitas antioksidan. Tujuan dari penelitina ini adalah menginversitagasi dan menganalisis peran 8-shogaol terhadap JNK. Protein JNK (ID: 464Y) diperoleh dari Protein Data Bank dan ligan 8-shogaol (CID:6442560 ) didapat dari pubchem. Ligan dan protein didocking menggunakan Hex 8.0.0. File dalam bentuk pdb divisualtisasi dan analisis menggunakan Discovery Studio Client 4.1 software. Interaksi ligan-protein menunjukan ikatan hidrogen pada residu asam amino LYS93 dan van der Waals pada 18 residu asam amino dengan energi ikatan-289.68cal/mol. Interkasi ini berpotensi sebagai penghambat kerja JNK dan dapat digunakan dalam terapi DMT2.Virtual screening: potential prediction of 8-shogaol againts c-Jun N-Terminal Kinase (JNK)AbstractJNK is one of gene that has a role in T2DM condition. To curve T2DM use JNK as potential healing using natural compounds. Eight-shogaol which found in ginger has function as a antioxidant.. The aim of the research is to investigate and analyze role 8-shogaol againts JNK. Protein JNK (ID: 464Y) was taken from Protein Data Bank and ligand 8-shogaol (CID:6442560 ) acquired from pubchem. Ligand and protein model were docked using Hex 8.0.0 software. Visualization and analysis molecular interactions by the Discovery Studio Client 4.1 software. Interaction ligand-protein showed one hydrogen bond in amino acid residue LYS93 and formed van der Waals in eighteen amino acid residues which energy binding -289.68cal/mol. This interaction has a potential to inhibit JNK role and lead to therapy T2DM.

scholarly journals Alignment of Alzheimer’s Disease Amyloid-β Peptide and Herpes Simplex Virus-1 pUL15 C-Terminal Nuclease Domain

2020 ◽  
Vol 4 (1) ◽  
pp. 373-377
Author(s):  
Steven Lehrer ◽  
Peter H. Rheinstein
Keyword(s):  
Herpes Simplex Virus ◽  
Immune System ◽  
Amino Acid ◽  
Herpes Simplex ◽  
Protein Data Bank ◽  
Amyloid Β ◽  
Data Bank ◽  
Amino Acid Residues ◽  
Simplex Virus ◽  
Hsv 1

Background: The cause of Alzheimer’s disease (AD) is poorly understood. Neurotropic microbes, particularly herpesviruses, might set off chronic neuroinflammation. Amyloid-β (Aβ) has antimicrobial properties and could represent a brain defense against infection. Objective: We searched for protein sequence alignment between herpes simplex virus type I (HSV-1) HSV-2, and Aβ. Methods: Protein data bank (pdb) structures for Aβ, HSV-1, and HSV-2 were searched on the RCSB Protein Data Bank. The protein structures were superimposed and aligned on PYMOL v 2.3.4. Results: For HSV-1 and Aβ, amino acid residues ser549 – his569 of HSV-1 aligned closely with residues asp7 - asn27 of Aβ. For HSV-2 and Aβ, amino acid residues of HSV-2 aligned less closely than those of HSV-1 with residues of Aβ. Conclusion: Conjugating and binding to the same alpha helix in the HSV-1 protease, Aβ could be marking HSV-1 for attack by the immune system, providing a rapid inherited immune response to a destructive neurotropic virus that would otherwise require the more time-consuming involvement of T-cells, B-cells, and the adaptive immune system. But older people do not respond to viral infections as well as younger individuals. When HSV-1 infection advances in an old person, more and more amyloid is produced, forming an adhesive web. As the brain tries to hold the pathologic process in check, neuroinflammation increases and spreads. Progressive neurodegeneration and cognitive decline are the outcome.

scholarly journals Characteristics of Interactions at Protein Segments External to Globular Domains in the Protein Data Bank

2018 ◽  
Author(s):  
Kota Kasahara ◽  
Shintaro Minami ◽  
Yasunori Aizawa
Keyword(s):  
Amino Acid ◽  
Protein Data Bank ◽  
Protein Function ◽  
Three Dimensional ◽  
Data Bank ◽  
Side Chain ◽  
Globular Domain ◽  
Amino Acid Residues ◽  
Structural Elements

ABSTRACTThe principle of three-dimensional protein structure formation is a long-standing conundrum in structural biology. A globular domain of a soluble protein is formed by a network of atomic contacts among amino acid residues, but regions external to globular domains, like loop and linker, often do not have intramolecular contacts with globular domains. Although these regions can play key roles for protein function as interfaces for intermolecular interactions, their nature remains unclear. Here, we termed protein segments external to globular domains as floating segments and sought for them in tens of thousands of entries in the Protein Data Bank. As a result, we found that 0.72 % of residues are in floating segments. Regarding secondary structural elements, coil structures are enriched in floating segments, especially for long segments. Interactions with polypeptides and polynucleotides, but not small compounds, are enriched in floating segments. The amino acid preferences of floating segments are similar to those of surface residues, with exceptions; the small side chain amino acids, Gly and Ala, are preferred, and some charged side chains, Arg and His, are disfavored for floating segments compared to surface residues. Our comprehensive characterization of floating segments may provide insights into understanding protein sequence-structure-function relationships.

scholarly journals In Silico Prediction, Molecular Docking and Dynamics Studies of Steroidal Alkaloids of Holarrhena pubescens Wall. ex G. Don to Guanylyl Cyclase C: Implications in Designing of Novel Antidiarrheal Therapeutic Strategies

Molecules ◽  
2021 ◽  
Vol 26 (14) ◽  
pp. 4147
Author(s):  
Neha Gupta ◽  
Saurav Kumar Choudhary ◽  
Neeta Bhagat ◽  
Muthusamy Karthikeyan ◽  
Archana Chaturvedi
Keyword(s):  
Molecular Docking ◽  
Amino Acid ◽  
Guanylyl Cyclase ◽  
Extracellular Domain ◽  
Enterotoxigenic Escherichia Coli ◽  
Watery Diarrhea ◽  
Guanylyl Cyclase C ◽  
Amino Acid Residues ◽  
Lead Compounds

The binding of heat stable enterotoxin (STa) secreted by enterotoxigenic Escherichia coli (ETEC) to the extracellular domain of guanylyl cyclase c (ECDGC-C) causes activation of a signaling cascade, which ultimately results in watery diarrhea. We carried out this study with the objective of finding ligands that would interfere with the binding of STa on ECDGC-C. With this view in mind, we tested the biological activity of a alkaloid rich fraction of Holarrhena pubescens against ETEC under in vitro conditions. Since this fraction showed significant antibacterial activity against ETEC, we decided to test the screen binding affinity of nine compounds of steroidal alkaloid type from Holarrhena pubescens against extracellular domain (ECD) by molecular docking and identified three compounds with significant binding energy. Molecular dynamics simulations were performed for all the three lead compounds to establish the stability of their interaction with the target protein. Pharmacokinetics and toxicity profiling of these leads demonstrated that they possessed good drug-like properties. Furthermore, the ability of these leads to inhibit the binding of STa to ECD was evaluated. This was first done by identifying amino acid residues of ECDGC-C binding to STa by protein–protein docking. The results were matched with our molecular docking results. We report here that holadysenterine, one of the lead compounds that showed a strong affinity for the amino acid residues on ECDGC-C, also binds to STa. This suggests that holadysenterine has the potential to inhibit binding of STa on ECD and can be considered for future study, involving its validation through in vitro assays and animal model studies.

scholarly journals ANALYSIS OF MOLECULAR DOCKING EFFICIENCY OF CLEISTANTHIN-A, AS AN ALTERNATIVE FOR NICOTINE ADDICTION

2018 ◽  
Vol 10 (4) ◽  
pp. 98
Author(s):  
A. Amala Lourthuraj ◽  
M. Masilamani Selvam ◽  
Bharathi Ravikrishnan ◽  
M. Vinoth ◽  
Waheeta Hopper
Keyword(s):  
Molecular Docking ◽  
Virtual Screening ◽  
Protein Data Bank ◽  
Acetylcholine Receptor ◽  
Nicotinic Acetylcholine Receptor ◽  
High Throughput ◽  
In Silico ◽  
Data Bank ◽  
Tobacco Consumption ◽  
Nicotinic Acetylcholine

Objective: The present research was aimed to understand the molecular docking efficiency of a plant-derived compound cleistanthin-A and a common ingredient in tobacco consumption nicotine with nicotinic acetylcholine receptor (nAChR).Methods: The 3-D structure of nAChR was retrieved from the protein data bank (ID 5AFH). Ligand was obtained from the PUBCHEM. The in silico protocol comprised of three steps: high-throughput virtual screening (HTVS), standard preci­sion (SP) and extra precision (XP). The screened molecules were ranked accordingly using glide score. Schrödinger tool was used to perform the docking analysis.Results: The binding efficiency of the nicotine and cleistanthin-A was found to be docked at the cys-cys loop of the receptor. Based upon the glide score and glide energy it can be reported that, nicotine binding can be inhibited by the binding of cleistanthin-A to the nAChR.Conclusion: The docking efficiency of cleistanthin-A was good compared to nicotine towards nAChR. Hence, cleistanthin–A was derived as a better choice as an alternative for nicotine in smoke therapy.

scholarly journals Molecular Modification of Fluoroquinolone-Biodegrading Enzymes Based on Molecular Docking and Homology Modelling

2019 ◽  
Vol 16 (18) ◽  
pp. 3407 ◽  
Author(s):  
Liu ◽  
Sun ◽  
Cui ◽  
Ding
Keyword(s):  
Molecular Docking ◽  
Amino Acid ◽  
Homology Modelling ◽  
Binding Affinities ◽  
The Novel ◽  
Amino Acid Residues ◽  
Degrading Enzyme ◽  
Degrading Enzymes ◽  
Docking Method ◽  
Degradation Effect

To improve the biodegradation efficiency of fluoroquinolone antibiotics during sewage treatment, fluoroquinolone aerobic, anaerobic and facultative degrading enzymes for fluoroquinolone degradation were modified by molecular docking and homology modelling. First, amino acid residues of the binding sites of degrading enzymes for the target fluoroquinolones ciprofloxacin (CIP), norfloxacin (NOR) and ofloxacin (OFL) were analysed by the molecular docking method. The hydrophobic amino acid residues within 5 Å of the target fluoroquinolone molecules were selected as the modification sites. The hydrophobic amino acid residues at the modified sites were replaced by the hydrophilic amino acid residues, and 150 amino acid sequence modification schemes of the degrading enzymes were designed. Subsequently, a reconstruction scheme of the degrading enzyme amino acid sequence reconstruction scheme was submitted to the SWISS-MODEL server and a selected homology modelling method was used to build a new structure of the degrading enzyme. At the same time, the binding affinities between the novel degrading enzymes and the target fluoroquinolones (represented by the docking scoring function) were evaluated by the molecular docking method. It was found that the novel enzymes can simultaneously improve the binding affinities for the three target fluoroquinolones, and the degradation ability of the six modification schemes was increased by more than 50% at the same time. Among the novel enzymes, the affinity effect of the novel anaerobic enzyme (6-1) with CIP, NOR and OFL was significantly increased, with increases of 129.24%, 165.06% and 169.59%, respectively, followed by the facultative enzyme and aerobic enzyme. In addition, the designed degrading enzymes had certain selectivity for the degradation of the target quinolone. Among the novel enzymes, the binding affinities of the novel anaerobic enzyme (6-3) and CIP, the novel aerobic enzyme (3-6) and NOR, and the novel facultative enzyme (13-6) and OFL were increased by 149.71%, 178.57% and 297.12% respectively. Calculations using the Gaussian09 software revealed that the degradation reaction barrier of the novel degrading enzyme (7-1) and CIP NOR and OFL decreased by 37.65 kcal·mol−1, 6.28 kcal·mol−1 and 6.28 kcal·mol−1, respectively, which would result in efficient degradation of the target fluoroquinolone molecules. By analysing the binding affinity of the degrading enzymes before and after the modification with methanol, it was further speculated that the degradation effect of the modified aerobic degrading enzymes on organic matter was lower than that before the modification, and the increase or decrease in the degradation effect was less than 10%. The mechanism analysis found that the interaction between the modified amino acid residues of the degrading enzymes and the fluoroquinolone molecules increased. The average distance between the amino acid residues and the fluoroquinolone molecules represented a comprehensive affinity effect, and its value was positively correlated with the degradation effect of the novel degrading enzymes.

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