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 IMAAAGINE: a webserver for searching hypothetical 3D amino acid side chain arrangements in the Protein Data Bank

2013 ◽  
Vol 41 (W1) ◽  
pp. W432-W440 ◽  
Author(s):  
Nurul Nadzirin ◽  
Peter Willett ◽  
Peter J. Artymiuk ◽  
Mohd Firdaus-Raih
Keyword(s):  
Amino Acid ◽  
Protein Data Bank ◽  
Data Bank ◽  
Side Chain ◽  
Amino Acid Side Chain

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 Analysis of Amino Acid Residues Involved in Catalysis of Polyethylene Glycol Dehydrogenase from Sphingopyxis terrae, Using Three-Dimensional Molecular Modeling-Based Kinetic Characterization of Mutants

2006 ◽  
Vol 72 (6) ◽  
pp. 4388-4396 ◽  
Author(s):  
Takeshi Ohta ◽  
Takeshi Kawabata ◽  
Ken Nishikawa ◽  
Akio Tani ◽  
Kazuhide Kimbara ◽  
...  
Keyword(s):  
Polyethylene Glycol ◽  
Amino Acid ◽  
Molecular Modeling ◽  
Binding Site ◽  
Active Sites ◽  
Substrate Binding ◽  
Three Dimensional ◽  
Kinetic Characterization ◽  
Amino Acid Residues

ABSTRACT Polyethylene glycol dehydrogenase (PEGDH) from Sphingopyxis terrae (formerly Sphingomonas terrae) is composed of 535 amino acid residues and one flavin adenine dinucleotide per monomer protein in a homodimeric structure. Its amino acid sequence shows 28.5 to 30.5% identity with glucose oxidases from Aspergillus niger and Penicillium amagasakiense. The ADP-binding site and the signature 1 and 2 consensus sequences of glucose-methanol-choline oxidoreductases are present in PEGDH. Based on three-dimensional molecular modeling and kinetic characterization of wild-type PEGDH and mutant PEGDHs constructed by site-directed mutagenesis, residues potentially involved in catalysis and substrate binding were found in the vicinity of the flavin ring. The catalytically important active sites were assigned to His-467 and Asn-511. One disulfide bridge between Cys-379 and Cys-382 existed in PEGDH and seemed to play roles in both substrate binding and electron mediation. The Cys-297 mutant showed decreased activity, suggesting the residue's importance in both substrate binding and electron mediation, as well as Cys-379 and Cys-382. PEGDH also contains a motif of a ubiquinone-binding site, and coenzyme Q10 was utilized as an electron acceptor. Thus, we propose several important amino acid residues involved in the electron transfer pathway from the substrate to ubiquinone.

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 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.

Schistosomal Sulfotransferase Interaction with Oxamniquine Involves Hybrid Mechanism of Induced-fit and Conformational Selection

2020 ◽  
Vol 16 (4) ◽  
pp. 451-459 ◽  
Author(s):  
Fortunatus C. Ezebuo ◽  
Ikemefuna C. Uzochukwu
Keyword(s):  
Molecular Dynamics ◽  
Amino Acid ◽  
Binding Energy ◽  
Binding Site ◽  
Conformational Dynamics ◽  
Side Chain ◽  
Amino Acid Residues ◽  
Conformational Selection ◽  
Hybrid Mechanism ◽  
Dynamics Simulations

Background: Sulfotransferase family comprises key enzymes involved in drug metabolism. Oxamniquine is a pro-drug converted into its active form by schistosomal sulfotransferase. The conformational dynamics of side-chain amino acid residues at the binding site of schistosomal sulfotransferase towards activation of oxamniquine has not received attention. Objective: The study investigated the conformational dynamics of binding site residues in free and oxamniquine bound schistosomal sulfotransferase systems and their contribution to the mechanism of oxamniquine activation by schistosomal sulfotransferase using molecular dynamics simulations and binding energy calculations. Methods: Schistosomal sulfotransferase was obtained from Protein Data Bank and both the free and oxamniquine bound forms were subjected to molecular dynamics simulations using GROMACS-4.5.5 after modeling it’s missing amino acid residues with SWISS-MODEL. Amino acid residues at its binding site for oxamniquine was determined and used for Principal Component Analysis and calculations of side-chain dihedrals. In addition, binding energy of the oxamniquine bound system was calculated using g_MMPBSA. Results: The results showed that binding site amino acid residues in free and oxamniquine bound sulfotransferase sampled different conformational space involving several rotameric states. Importantly, Phe45, Ile145 and Leu241 generated newly induced conformations, whereas Phe41 exhibited shift in equilibrium of its conformational distribution. In addition, the result showed binding energy of -130.091 ± 8.800 KJ/mol and Phe45 contributed -9.8576 KJ/mol. Conclusion: The results showed that schistosomal sulfotransferase binds oxamniquine by relying on hybrid mechanism of induced fit and conformational selection models. The findings offer new insight into sulfotransferase engineering and design of new drugs that target sulfotransferase.

Synthesis and conformation of sequential basic polypeptides with branched and linear side chains

1985 ◽  
Vol 50 (12) ◽  
pp. 2925-2936 ◽  
Author(s):  
Štěpánka Štokrová ◽  
Jan Pospíšek ◽  
Jaroslav Šponar ◽  
Karel Bláha
Keyword(s):  
Amino Acid ◽  
Salt Concentration ◽  
Salt Solution ◽  
Theoretical Work ◽  
Side Chain ◽  
Amino Acid Residues ◽  
Cd Spectra ◽  
Low Salt ◽  
Conformational Freedom ◽  
Basic Polypeptides

Polypeptides (Lys-X-Ala)n and (Lys-X-Gly)n in which X represents residues of isoleucine and norleucine, respectively, and polypeptide (Tle-Lys-Ala)n, were synthesized via polymerization of 1-hydroxysuccinimidyl esters of the appropriate tripeptides to complete previously studied series. Circular dichroism (CD) spectra of the respective polymers were measured as a function of pH and salt concentration of the medium. The results were correlated with those obtained previously with the same series containing different amino acid residues at the X-position. The helix forming ability of the polypeptides (Lys-X-Ala)n with linear X side chain was found to be independent of the length. In the series (Lys-X-Gly)n the unordered conformation was the most probable one except (Lys-Ile-Gly)n. This polymer assumed the β conformation even in low salt solution at neutral pH. An agreement with some theoretical work concerned with the restriction of conformational freedom of amino acid residue branching at Cβ atom with our experimental results is evident.

Analogues of the cholecystokinin octapeptide modified in the central part of the molecule

1991 ◽  
Vol 56 (9) ◽  
pp. 1963-1970 ◽  
Author(s):  
Jan Hlaváček ◽  
Václav Čeřovský ◽  
Jana Pírková ◽  
Pavel Majer ◽  
Lenka Maletínská ◽  
...  
Keyword(s):  
Amino Acid ◽  
Biological Activities ◽  
Point Of View ◽  
Biologically Active ◽  
Side Chain ◽  
Amino Acid Residues ◽  
Cholecystokinin Octapeptide ◽  
Biological Tests ◽  
Biological Potency ◽  
Biologically Active Conformation

In a series of analogues of the cholecystokinin octapeptide (CCK-8) the amino acid residues were gradually modified by substituting Gly by Pro in position 4, Trp by His in position 5, Met by Cle in position 6, or the Gly residue was inserted between Tyr and Met in positions 2 and 3 of the peptide chain, and in the case of the cholecystokinin heptapeptide (CCK-7) the Met residues were substituted by Nle or Aib. These peptides were investigated from the point of view of their biological potency in the peripheral and central region. From the results of the biological tests it follows that the modifications carried out in these analogues and in their Nα-Boc derivatives mean a suppression of the investigated biological activities by 2-3 orders of magnitude (at a maximum dose of the tested substance of 2 . 10-2 mg per animal).This means that a disturbance of the assumed biologically active conformation of CCK-8, connected with a considerable decrease of the biological potency of the molecule, takes place not only after introduction of the side chain into its centre (substitution of Gly4), but also after the modification of the side chains of the amino acids or by extension of the backbone in further positions around this central amino acid.

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