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"Sebagai upaya dalam memahami netralisasi virus H5N1 oleh antibodi manusia, simulasi dinamika molekuler dua kompleks antibodi-antigen dilakukan. Tiga struktur molekul yang membentuk dua kompleks tersbeut dibentuk termasuk antigen hemagglutinin Vietnam 2IBX, hemagglutinin Indonesia CDC, dan fragmen variabel dari antibodi 8H5 atau 8H5Fv.Dalam penelitian ini komplesks 8H5Fv-2IBX dan 8H5Fv-CDC diproduksi melalui pemodelan struktur molekul, homology modeling, dan molecular docking. Dua kompleks tersebut lalu melewati simulasi dinamika molekuler selama 2 nanosekon untuk menginvestigasi kestabilan struktur kompleks dan aktivitas netralisasi yang dapat diamati dengan berfokus pada epitope netralisasi masing ? masing hemagglutinin yang didapatkan hasil molecular docking.Didapatkan bahwa sifat dinamis atom ? atom pembentuk molekul tidak menihilkan aktivitas netralisasi. Dengan mengamati epitope netralisasi masing ? masing hemagglutinin juga didapatkan bahwa aktivitas netralisasi lebih efektif pada hemagglutinin 2IBX (Vietnam) dibandingkan dengan hemagglutinin Indonesia (CDC) berdasarkan kalkulasi solvent accessible surface (SAS), energi, root mean square displacement (RMSD), dan analisis okupansi ikatan hidrogen.

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In an effort to study the H5N1 virus neutralisation by a human antibody, molecular dynamics simulations on two antibody-antigen complexes were conducted. Three molecular structures were formed in this study including the Vietnamese hemagglutinin 2IBX, the Indonesian hemagglutinin CDC, and a variable fragment of the 8H5 antibody or 8H5Fv.

In this study the complexes 8H5Fv-2IBX and 8H5Fv-CDC, that were produced by molecular modeling, homology modeling and molecular docking, was subjected to a 2 nanosecond molecular dynamics simulation each to investigate the stability of such complexes and the maintenance of the neutralising activity that was observed by focusing on the neutralising epitopes that were predicted by molecular docking.

It is was found that the dynamic nature of the molecules in study did not negate the steric hindrance occuring from the antibody variable fragment 8H5Fv with the hemagglutinins, therefore suggesting that the 8H5 antibody should be able to neutralise these two hemagglutinins. By solvent accessible surface (SAS) calculations, energy analysis, root mean square displacement (RMSD) analysis, and also hydrogen bond occupance it was also found that the the 8H5Fv seem to be more effective against the 2IBX (Vietnamese) hemagglutinin than against the CDC (Indonesian) hemagglutinin."

"Ab initio molecular dynamics revolutionized the field of realistic computer simulation of complex molecular systems and processes, including chemical reactions, by unifying molecular dynamics and electronic structure theory. This text provides a presentation of this rapidly growing field"

"Rem GTPase is a member ofRGK subfamily (Rad, Rem, Rem2, Gem and Kir) found recently. Rem is highly expressed at cardiac muscle.[l] Crystal structure of Rem (2NZJ) unveiled disordered structures of switch I (residue 102-110) and switch II (residue 135-145). These both regions have been acknowledged to be involved in nucleotide binding and GTP hydrolysis . The purpose of this study is to construct Rem GTPase model by using homology modeling method and to analyze the movements of Rem by performing molecular dynamics (MD) simulation. The selected Rem model, model_Rem_6.pdb, was constructed from multiple templates composed of 421P _A (Ras), 2A78_A (RalA), and 2NZJ_A. Furthermore Rem model was used for ten nanoseconds MD simulation provided for GDP, GTP and without ligand system by using GROMACS 3.3.2. The result was observed from visualization point of view, potential energy, RMSD and RMSF factors. MD simulation revealed that switch regions moved more flexible than other regions in the structure and tended to move away from nucleotide binding site, distinct from the movements of Ras switches which had shown interactions occurred within y­phosphate and both switches."

"ABSTRAKDemam dengue adalah penyakit menular yang ditransmisikan oleh nyamuk Aedes aegypti. WHO melaporkan bahwa wilayah Asia tenggara dan daerah Pasifik barat menanggung hampir 75% penyakit dengue secara global. Virus dengue menimbulkan ancaman global yang mempengaruhi 3,9 milyar orang di 128 negara dengan perkiraan 2,1 juta kasus demam berdarah dengue dan 21.000 kematian per tahun di seluruh dunia. Pada tahun 2015 tercatat terdapat 126.675 kasus DBD di 34 provinsi di Indonesia, dengan 1.229 orang di antaranya meninggal dunia. Enzim alfa-glukosidase merupakan target antiviral yang valid untuk enveloped virus. Inhibisi enzim RE alfa-glukosidase akan mengganggu proses pematangan dan fungsi glikoprotein envelop pada virus. Hal ini  menghambat proses perakitan partikel virus dan sekresinya. Hasil penelitian membuktikan bahwa inhibisi enzim alfa-glukosidase II  cukup dalam aktivitas antiviral sel inang  melawan demam dengue secara in vitro dan in vivo. Penemuan obat berbasis fragmen telah menjadi metode untuk menemukan kandidat obat baru. Pendekatan metode ini pertama-tama adalah mengidentifikasi fragmen yaitu molekul sangat kecil yang memiliki ukuran setengah dari ukuran obat-obatan secara umum. Fragmen-fragmen kemudian ditautkan bersama untuk membentuk obat baru. Pada penelitian ini digunakan enzim RE alfa-glukosidase II dengan kode 5IED. Sebanyak 281 senyawa baru berhasil diciptakan secara komputasi berdasarkan struktur 3D protein 5IED. Setelah dilakukan simulasi penambatan molekuler, uji toksisitas, uji druglikeness, uji farmakokinetika dan analisis interaksi protein-ligan, dipilih tiga senyawa terbaik yaitu LB.5 G2D, LO.1 G2D dan LX.23 G2D. Studi dinamika molekuler menunjukkan tiga residu asam amino yang berperan penting dalam pengikatan ligan LX.23 G2D dengan protein 5IED yaitu Asp451, Met565 dan Asp640.

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Dengue fever is a contagious disease transmitted by Aedes aegypti mosquitoes. WHO reported that south east Asia and the western Pacific region bear nearly 75% of global dengue diseases. The dengue virus poses a global threat affecting 3.9 billion people in 128 countries with an estimated 2.1 million cases of DHF / DSS and 21,000 deaths per year worldwide. In 2015 there were 126,675 dengue cases recorded in 34 provinces in Indonesia, with 1,229 of them dying. The alpha-glucosidase enzyme is a valid antiviral target for enveloped viruses. Inhibition of ER alpha-glucosidase enzyme will interfere the maturation process and function of viral envelope glycoproteins. This inhibits the process of assembling virus particles and their secretions. Inhibition of ER alpha-glucosidase II enzyme is sufficient in antiviral activity of host cells against dengue fever in vitro and in vivo. Fragment-based drug discovery (FBDD) has become a tool for discovering drug leads. The approach first identifies fragments, tiny molecules, which are about half size of common drugs. The fragments are then linked together to generate drug leads. This research used ER alpha-glucosidase II enzyme with PDB ID 5IED. As much as 281 new compounds were developed computationally based on 3D structure of 5IED protein. After molecular docking simulations, toxicity tests, druglikeness tests, pharmacokinetic tests and protein-ligand interactions analyses, three best ligands were chosen namely LB.5 G2D, LO.1 G2D and LX.23 G2D. An LX.23 G2D molecular dynamics simulation showed that three amino acid residues played a very important role in ligand binding to 5IED protein. The amino acid residues were Asp451, Met565 and Asp640.     

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"Pada penelitian terdahulu telah diusulkan dua buah ligan polipeptida siklik disulfida-CDEEC dan CDGSC-sebagai inhibitor potensial untuk enzim RNA-dependent RNA-polymerase virus dengue melalui molecular docking. Simulasi molecular docking dilakukan dengan keadaan tanpa pelarut dimana enzim dibuat rigid dan ligan dibiarkan bebas berotasi untuk mencari konformasi terbaik. Pada kenyataan dalam sistem seluler terdapat pelarut yang membuat enzim memiliki pergerakan dinamis. Oleh karena itu dalam penelitian ini dilakukan simulasi dinamika molekul untuk memperkirakan sistem kompleks enzim-ligan yang lebih nyata. Simulasi dinamika molekul dijalankan pada selama 5ns pada suhu 300 dan 312 K. Pada akhir simulasi 300 K CDEEC membentuk ikatan dengan dua residu penting pada RdRp yaitu Arg-729 dan Arg-737 sedangkan CDGSC tidak berikatan dengan residu penting manapun. CDEEC juga memberikan hasil yang lebih baik dibanding CDGSC pada simulasi 312 K. CDEEC membentuk ikatan dengan dua residu penting yaitu Arg-737 dan Ser-710 sementara CDGSC tidak berikatan dengan satupun residu penting. Berdasarkan hasil tersebut CDEEC merupakan inhibitor yang lebih baik dan layak untuk dikembangkan sebagai obat anti dengue.

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Previous researches have proposed two ligands of disulfide cyclic polypeptide which are CDEEC and CDGSC as potential inhibitor of RNA-dependent RNA-polymerase dengue virus by molecular docking. Molecular docking simulation is done without a solvent in which enzyme is made rigid and ligand was left free to rotate to find teh best conformation. In fact in a cellular system there is a solvent that makes the enzyme has a dynamic movement. Therefore in this paper molecular dynamics simulation is done to estimate more reliable condition of enzyme-ligand complex. In this work molecular dynamics simulation is done during 5 ns with two different temperature, 300 and 312 K. At the end of MD simulation at 300 K, CDEEC binds to two RdRp important residues, Arg-729 and Arg-737 while CDGSC doesn’t bind to any important residues. Simulation at 312 K also revealed nearly the same result, CDEEC binds to two RdRP important residues, Arg-737 and Ser-710, whereas CDGSC doesn’t bind to any important residues. Based on the result of these two simulation, CDEEC is proposed as a better inhibitor of RdRp dengue virus and feasible to be developed as anti-dengue drug."

"Liposom adalah teknologi pengiriman obat untuk meningkatkan kemanjuran dan keamanan obat. Liposom adalah vesikel amphiphilic yang memiliki bagian kutub dan non-kutub. Ini memungkinkan liposom untuk membawa obat-obatan hidrofilik dan hidrofobik. Kafein adalah zat psikoaktif yang disebut xanthine alkaloid yang memiliki sifat penetrasi kulit yang buruk. Ini karena kafein memiliki sifat hidrofilik. Jadi untuk meningkatkan konsentrasi kafein di lapisan kulit yang lebih dalam, diperlukan vesikel seperti liposom. Proses pembuatan liposom konvensional membutuhkan waktu lama, rumit dan dapat menghasilkan racun dari residu pelarut organik yang digunakan. Simulasi dinamika molekul dapat mengatasi keterbatasan pembuatan liposom konvensional dengan memvisualisasikan ikatan molekul dan menganalisis sifat-sifat liposom berdasarkan interaksi antar ikatan. Molekul kafein akan dikombinasikan dengan molekul kolesterol dan fosfolipid DPPC (1,2-dipalmitoyl-sn-glycero-3-phosphocholine). Simulasi dinamika molekul dilakukan pada Kafein dan liposom dengan komposisi Kolesterol - DPPC (1: 1; 1: 2; 1: 4) yang dipanaskan oleh 323 K dalam kotak virtual 100 Å dan diproduksi pada 125 ns. Sistem akan diproses menggunakan kuning. Visualisasi menghasilkan ikatan antar molekul untuk membentuk koleksi padat, ikatan tidak sempurna antar molekul dalam bentuk bola berlubang. Ini karena keterbatasan komputer dan kebutuhan untuk pelarut yang cocok. Sedangkan hasil analisis yang diperoleh dari ketiga liposom di atas stabil pada 323 K dan Kolesterol-DPPC (1: 4) memiliki ikatan paling padat dan volume terkecil adalah 44,7 Å X 43,4 Å X 58,8 Å (X, Y, Z). Energi potensial dari ketiga liposom akan berkurang yang menunjukkan keseimbangan energi di semua liposom.

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Liposomes are a drug delivery technology to improve the efficacy and safety of drugs. Liposomes are amphiphilic vesicles that have polar and non-polar sections. This allows the liposome to carry hydrophilic and hydrophobic drugs. Caffeine is a psychoactive substance called xanthine alkaloid which has poor skin penetration properties. This is because caffeine has hydrophilic properties. So to increase the concentration of caffeine in the deeper layers of the skin, vesicles such as liposomes are needed. The process of making conventional liposomes takes a long time, is complicated and can produce toxins from the residues of organic solvents used. Molecular dynamics simulations can overcome the limitations of making conventional liposomes by visualizing molecular bonds and analyzing the properties of liposomes based on interactions between bonds. Caffeine molecules will be combined with cholesterol molecules and DPPC phospholipids (1,2-dipalmitoyl-sn-glycero-3-phosphocholine). Molecular dynamics simulations were carried out on Caffeine and liposomes with Cholesterol-DPPC composition (1: 1; 1: 2; 1: 4) heated by 323 K in a 100 Å virtual box and produced at 125 ns. The system will be processed using yellow. Visualization produces bonds between molecules to form solid collections, imperfect bonds between molecules in the shape of a hollow ball. This is due to computer limitations and the need for suitable solvents. While the analysis results obtained from the three liposomes above are stable at 323 K and Cholesterol - DPPC (1: 4) has the densest bond and the smallest volume is 44.7 Å X 43.4 Å X 58.8 Å (X, Y, Z). The potential energy of all three liposomes will decrease which shows the energy balance in all liposomes."

"Biopelumas berbahan dasar metil ester dari minyak kelapa sawit (POME) adalah salah satu pelumas alternatif yang paling mungkin dikembangkan saat ini karena berasal dari minyak tumbuhan yang ketersediaannya tidak terbatas. Sementara itu, MXene, material baru berdimensi dua, belum banyak diaplikasikan sebagai zat aditif ke dalam pelumas terutama biopelumas. Menggunakan pendekatan simulasi dinamika molekuler, kestabilan MXene didalam POME beserta sifat termofisika campurannya akan diprediksikan. Kedalam campuran POME-MXene kemudian ditambahkan juga partikel nano unggul lainnya yaitu Al2O3. Dengan visualisasi, fenomena interaksi secara atomik yang terjadi diantara; POME-MXene, MXene- Al2O3 dan POME-MXene/Al2O3 dapat diketahui. Prediksi kestabilan, densitas, koefisien difusi dan konduktivitas termal dihasilkan dengan metode Equilibrium Molecular Dynamics (EMD) sedangkan metode Non-Equilibrium Molecular Dynamics (NEMD) diterapkan untuk memprediksikan nilai viskositas. Potensial Condensed-phase Optimized Molecular Potential for Atomistic Potential Studies (COMPASS) yang dihibridisasi dengan potensial sederhana LJ 12-6 digunakan untuk mendefinisikan interaksi intra dan inter-molekular pada molekul MXene, Al2O3 serta campuran POME-MXene/Al2O3. Dibandingkan dengan hasil uji laboratorium, didapatkan deviasi rata-rata kurang dari 10% sehingga sifat termofisika pada POME dapat diprediksikan dengan baik. Hasil visualisasi yang diperoleh mampu menjawab bagaimana mekanisme dan bentuk agregasi nanopartikel dalam POME, sehingga dapat menjelaskan sifat termofisika yang khas pada campuran POME dan MXene beserta hibridisasinya. Terutama nilai konduktivitas termal yang semakin turun seiring naiknya temperatur.

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Due to its sustainable resources, Palm Oil Methyl Ester-based lubricants (POME) is one of the alternative lubricants most likely to be developed today. In this study, POME was reinforced by a novel 2D nanomaterial, MXene and other prominent nano material Al2O3. Using molecular dynamics simulation, the stability of MXene in POME and its thermophysical properties were predicted. The predicted interaction between two different dimension (MXene-Al2O3) were also covered. With visualization, other phenomenon of atomic interactions that occur between; POME-MXene and POME-MXene/Alumina were revealed. Predictions of stability, density, diffusion coefficient and thermal conductivity were generated by EMD method while the NEMD method was applied to predict viscosity values. COMPASS which was used to define intra-molecular interactions of POME was hybridized with the simple potential LJ 12-6 which defines the intra and inter-molecular interactions of MXene, Alumina and POME-MXene/Alumina molecules. Compared to laboratory test results, the average deviation is less than 10% so that the thermophysical properties of POME in a good agreement. The visualization results obtained were able to answer how the mechanism and form of nanoparticle aggregation in POME, so as to explain the thermophysical properties typical of the mixture of POME and MXene and its hybridization. Especially the value of thermal conductivity that decreases as the temperature rises."

"ABSTRAKDiabetes merupakan penyakit yang dikarakterisasi dengan meningkatnya kadar gula darah yang yang diakibatkan defisiensi insulin, resistensi insulin atau keduanya. Pengobatan diabetes berfokus pada insulin, dimana efikasinya dapat berkurang seiring penyakit berprogresi. Golongan penghambat Sodium-Glucose Linked Transporter 2 (SGLT2) merupakan golongan obat diabetes baru dengan mekanisme pengaturan kadar glukosa darah independent dari insulin, ditambah khasiat menurunkan resiko kardiovaskular dan berat badan. Fakultas Farmasi Universitas Indonesia berkontribusi dalam pengembangan golongan obat ini dengan metode in silico melalui penapisan virtual berbasis ligan berdasarkan gugus farmakofor dari pangkalan data tanaman herbal Indonesia, dan penapisan virtual berbasis struktur dengan model homologi hSGLT2 dari pangkalan data ZINC15. Hasil penapisan virtual tersebut dilakukan identifikasi lebih lanjut dengan simulasi dinamika molekuler selama 20 nanodetik untuk memperoleh perkiraan yang paling mendekati kondisi eksperimental. Sebelum simulasi, dilakukan pemerolehan model interaksi pada hasil penapisan virtual berbasis ligan dilakukan dengan penambatan molekuler dengan AutoDock terhadap makromolekul hasil pemodelan homologi dari SWISSMODEL. Interaksi ligan-reseptor dilihat dari interaksi hidrogen dan energi bebas ikatan ligan dibandingkan kontrol positif dengan MM/PB(GB)SA. Hasil studi dinamika molekuler menunjukkan empat senyawa dengan ∆G MM/PB(GB)SA lebih kecil dibanding kontrol positif, diantaranya zinc000146809581, cucumerin A, zinc000038175116, dan zinc000095913941 dengan jumlah ikatan hidrogen yang lebih banyak atau dapat bersaing dengan kontrol positif.

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ABSTRACT

Diabetes is a non-communicable disease that is characterized by the rising of blood glucose due to deficiency of insulin, insulin resistance, or both. Pharmacological treatment of diabetes mainly focuses on insulin, which decreases in efficacy once the disease progresses. SGLT2 inhibitors are diabetic treatments available in recent years with blood glucose control mechanism independent from insulin. Two in silico research were done in Faculty of Pharmacy from Universitas Indonesia to find more compounds of potential SGLT2 inhibition action by virtual screening of ligand based on Indonesian Herbal Database, dan of structure-based on the ZINC herbal database. In this study, the docked interaction models of the compounds acquired from those two virtual screening methods are analyzed for their ligand-receptor interactions by 20 nanoseconds of molecular dynamic simulations, with the ligand-based virtual screening results were first docked with macromolecule from homology modelling. The ligand-receptor interactions are observed by its calculated binding free energy and their hydrogen interactions with the protein, compared with known drugs of SGLT2 inhibitors as positive controls. The result of this study has shown four compounds with lower ∆G MM/PB(GB)SA than the positive controls, cucumerin A, zinc000146809581, zinc000038175116, and zinc000095913941 with more or comparable hydrogen interactions with positive controls.

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