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"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."

"SIRT1 merupakan salah satu dari tujuh sirtuin manusia SIRT1-7 yang termasuk dalam HDAC kelas III. Sejumlah penelitian tentang SIRT1 telah banyak dibuktikan berperan dalam regulasi metabolisme seluler serta sering dihubungkan dengan pathogenesis penyakit seperti kanker dan penyakit nuerodegeneratif. Untuk menemukan kandidat obat yang baik beberapa menggunakan metode in silico sebagai tool yang cepat dalam menganalisis aktifitas biologis obat secara virtual.Metode in silico dalam penelitian ini dimulai dari penapisan virtual, penambatan molekul dan simulasi dinamika molekuler yang menggunakan database herbal Indonesia untuk menemukan senyawa kandidat yang berpotensi sebagai inhibitor SIRT1.Hasilnya diperoleh ada enam senyawa kandidat dari database Herbal Indonesia yang memiliki potensi sebagai inhibitor SIRT1 yaitu 5-oxocoronaridine, 3-oxocoronaridine, 5-hydroxy-6-oxocoronaridine, dregamine, isovoacristine dan tabernaemontanine.Hasil penambatan molekul senyawa kandidat terhadap dua makromolekul SIRT1 PDB ID: 4I5I dan 4ZZI menunjukkan nilai pengikatan energi bebas senyawa kandidat mendekati dan lebih tinggi dari senyawa ligand co-kristal. Dari analisis simulasi dinamika molekuler diperoleh energi bebas MMPBSA di atas -21 kkal/ mol sedangkan occupancy ikatan hidrogen residu Ile347 dan Asp348 diatas 80 .

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SIRT1 is one of seven human sirtuins SIRT1 7 are included in class III of HDAC. A number studies of SIRT1 has been widely demonstrated a role in the regulation of cellular metabolism and linked to pathogenesis of diseases such as cancer and neurodegeneratif diseases. To find a good drug candidates could using in silico methods as a quick tool in analyzing the biological activity of drugs virtually.In silico methods in this research started from a virtual screening, docking and molecular dynamics simulations that use Indonesian herbal database to find potential candidate compounds as SIRT1 inhibitor.The result was obtained there are six candidates compound of Indonesian Herbal database that has potential as SIRT1 inhibitor that is 5 oxocoronaridine, 3 oxocoronaridine, 5 hydroxy 6 oxocoronaridine, dregamine, isovoacristine and tabernaemontanine.Docking results shown that molecule candidate compounds against two of macromolecules SIRT1 PDB ID 4I5I and 4ZZI have value of the candidate compound binding free energy approach and higher than the co crystal ligands. From the analysis of molecular dynamics simulations obtained free energy MMPBSA about 21 kcal mol while occupancy hydrogen bonding of residues Ile347 and Asp348 about 80 ."

"Obat ndash, obat golongan statin berkhasiat sebagai penurun kolesterol dan digunakan sebagai pencegahan pertama penyakit - penyakit kardiovaskuler. Namun, beberapa studi menyatakan bahwa ditemukan berbagai efek samping akibat penggunaan statin. Pencarian senyawa sebagai alternatif untuk pengobatan hiperkolesterlemia ditemukan dalam kandungan ekstrak biji melinjo. Ekstrak diklormetan memperlihatkan aktivitas penghambatan terhadap Hidroksimetilglutaril KoA Reduktase HMGCR berdasarkan uji in vitro sehingga berpotensi mengurangi pembentukan kolesterol dalam darah. Percobaan melalui penambatan molekuler menggunakan Autodock dan simulasi dinamika molekuler menggunakan AMBER dilakukan sebagai pelengkap terhadap uji in vitro. Suhu yang diterapkan dalam simulasi adalah 300 K sebagai suhu acuan dan 310 K sebagai penyesuaian dengan suhu tubuh normal. Parameter ndash; parameter yang diamati antara lain interaksi senyawa ligan dengan residu, afinitas ikatan, RMSD, RMSF, analisis ikatan hidrogen, MMPBSA dan MMGBSA. Dalam simulasi ini, trans-resveratrol, trans-piceid, Gnemonol M, Gnemonosida B, Viniferin dan Gnetin C memberikan energi lebih rendah dibandingkan HMG yang berperan sebagai ligan alami, sehingga berpotensi sebagai inhibitor alternatif terhadap HMGCR. Rentang energi untuk docking ligan ndash; ligan adalah -5,43 kkal/mol hingga 8,63 kkal/mol, serta -11,1 kkal/mol hingga 31,38 kkal/mol untuk simulasi. Suhu simulasi yang lebih disukai adalah 310 K karena terbentuk lebih banyak interaksi dan diperoleh afinitas yang lebih tinggi dibandingkan suhu 300 K.

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Statins are cholesterol lowering drug and used as primary prevention of cardiovascular diseases CVD , but numerous studies show adverse effects of statin medication. Recent study found alternative nature compounds as treatment of high blood cholesterol level which are contained within melinjo seed extract. Dichloromethane extract has inhibitory activity over Hydroxymethylglutaryl CoA Reductase HMGCR based on in vitro study, therefore has potent activity for lowering blood cholesterol. Molecular docking using Autodock and molecular dynamic simulation using AMBER are conducted for complementary study to in vitro experiment. Simulation was set at 300 K as default temperature and 310 K, normal human body temperature. The main parameters of this study are ligand residue interaction, binding affinity, RMSD, RMSF, hydrogen bonds analysis, MMPBSA and MMGBSA. In this simulation, trans resveratrol, trans piceid, Gnemonol M Gnemonoside B, Viniferin and Gnetin C have lower energy than HMG, the original ligand of HMGCR. Free energy binding obtained from docking range between 5,43 kcal mol to 8,63 kcal mol and 11,1 kcal mol to 31,38 kcal mol for the simulation. Also, simulation at 310 K is preferable than 300 K as more interactions are performed and higher affinity is obtained."

"Gout merupakan suatu penyakit berupa inflammatory arthritis yang berhubungan erat dengan gangguan metabolisme purin yang memicu peningkatan kadar asam urat dalam darah (hiperurisemia). Pengobatan yang umum dilakukan untuk menurunkan kadar asam urat dalam serum darah adalah dengan melakukan inhibisi aktivitas enzim Xanthine Oxidase (XO). Penelitian sebelumnya menemukan enyawa baru dari propolis Tetragonula Sapiens dapat menginhibisi enzim XO dan berpotensi menjadi zat aktif obat anti-gout. Penelitian ini dilakukan studi komputasi untuk memahami jenis dan mekanisme inihibisi XO oleh senyawa baru propolis T. sapiens. Penambatan molekuler dilengkapi dengan MPS Approach dan protein side-chain flexibility. Hasil penambatan molekuler menunjukkan energi ikatan terendah antara ligan dan reseptor terjadi pada domain intermediate dan bukan pada situs aktif, yang berpotensi inhibisi terjadi secara non-kompetitif. Kemudian dibuat dua sistem dengan dan tanpa inhibitor dan dilakukan simulasi MD. RMSD sistem tanpa inhibitor berada pada rentang 0,3-0,4 nm dan dengan inhibitor pada rentang 0,2-0,3 nm. Nilai Rg masing-masing secara berurutan sebesar 3,18 nm dan 3,19 nm. Okupansi ikatan hidrogen yang terbentuk mencapai 100% dengan residu Asp1170(1171). Hasil simulasi menunjukkan bahwa kompleks XO dengan senyawa propolis terjadi ekspansi struktur dibandingkan kompleks tanpa inhibitor dan inhibisi memiliki interaksi yang stabil.

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Gout is a disease in the form of inflammatory arthritis that is closely related to purine metabolism disorders that trigger increased levels of uric acid in the blood (hyperuricemia). A common treatment to reduce uric acid levels in blood serum is by inhibiting the activity of the Xanthine Oxidase (XO) enzyme. Previous research found a new compound from propolis Tetragonula Sapiens can inhibit the enzyme XO and has the potential to be an active substance in anti-gout drugs. This research is a computational study to understand the type and mechanism of XO inhibition by the new compound T. sapiens propolis. Molecular docking is complemented by the MPS Approach and protein side-chain flexibility. The molecular docking results show that the lowest binding energy between the ligand and the receptor occurs in the intermediate domain and not at the active site, which has the potential for inhibition to occur in a non-competitive manner. Then two systems with and without inhibitors were made and MD simulation was performed. The RMSD of the system without the inhibitor was in the range of 0.3-0.4 nm and with the inhibitor in the range of 0.2-0.3 nm. The Rg values ​​were respectively 3.18 nm and 3.19 nm, respectively. Occupancy of hydrogen bonds formed reaches 100% with Asp1170(1171) residues. The simulation results showed that the XO complex with propolis had a structural expansion compared to the complex without inhibitor and the inhibition had a stable interaction."

"Histon Deasetilase 2 (HDAC2) merupakan salah satu enzim dari suatu superfamily 18 enzim zinc-dependent yang kini tengah banyak diteliti sebagai target terapeutik. HDAC2 merupakan bagian dari HDAC kelas 1 yang diketahui memiliki aktivitas kuat sebagai katalis, dan umumnya merupakan target bagi inhibitor HDAC (HDACi). HDAC2 berperan pada gejala komplikasi akhir diabetes seperti nefropati diabetes. Sehingga penelitian lebih lanjut terkait inhibitor enzim-enzim HDAC khususnya HDAC2 perlu dikembangkan.Dalam penelitian ini, diteliti senyawa-senyawa dari basis data herbal Indonesia terhadap aktivitasnya sebagai inhibitor HDAC2, dengan melakukan penapisan virtual, untuk mendapatkan senyawa-senyawa pilihan, kemudian dilakukan simulasi dinamika molekuler untuk mengetahui interaksi senyawa sebagai inhibitor enzim. Didapatkan sepuluh besar peringkat senyawa penapisan virtual, kemudian diambil lima diantaranya dengan kriteria terbaik untuk dilakukan simulasi dinamika molekuler yaitu senyawa Boesenbergin B, Pongachalcone I, 6,8-Diprenylgenistein, Marmin, Mangostin, dengan kristal ligan N-(2-aminophenyl)benzamide sebagai kontrol positif, dengan nilai ΔG secara berturut-turut -8.28; -9.15; -7.05; -9.07; -7.15 dan ΔG kontrol positif -10.27. Dari simulasi dinamika molekuler diketahui aktivitas inhibitor HDAC2 berinteraksi pada residu asam amino penting yaitu His145C, Tyr308C, Zn379C, Leu276C, Phe155C, Phe210C, Leu144C, Met35C.

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Histone Deacetylase 2 (HDAC2) is one of a superfamily of 18 zinc-dependent enzymes, which now being widely investigated as therapeutic targets. HDAC2 is part of class I HDAC enzymes which knownly active as a strong catalys, and generally is the target for HDAC inhibitors (HDACi). HDAC2 play a role in the symptoms of late complications of diabetes such as diabetic nephropathy. So further research related to HDAC inhibitors, particularly HDAC2 need to be developed.In this study, research will be performed using virtual screening method to obtain several herbal compounds against their activities as HDAC2 inhibitors from the Indonesian herbal database, molecular dynamics simulations are then conducted to understand the interaction of compounds as inhibitors of the enzyme. The results of virtual screening process managed to obtained ten compounds with the highest Pharmacophore fit score rating, and would selected five compounds with the best criteria for molecular dynamics simulations, which are Boesenbergin B, Pongachalcone I, 6,8-Diprenylgenistein, Marmin, Mangostin, and active crytal ligand N-(2-aminophenyl)benzamide as a positive control, with respectively ΔG values obtained -8.28; -9.15; -7.05; -9.07; -7.15 and -10.27 as the ΔG value of active crystal ligand. From moleculer dynamics simulation of the activity of HDAC2 inhibitors are known to interact in two important amino acid residue that is His145C, Tyr308C, Zn379C, Leu276C, Phe155C, Phe210C, Leu144C, Met35C."

"Senyawa yang berperan sebagai inhibitor HDAC kelas IIa telah banyak dikembangkan sebagai obat antikanker, antiinflamasi, penyakit Huntington, human papiloma virus dan antidiabetes. Senyawa inhibitor HDAC antara lain golongan hydroxamic acid, peptida siklik, asam alifatik dan benzamide. Metode yang digunakan untuk mencari senyawa inhibitor HDAC kelas IIa salah satunya adalah melalui pendekatan farmakofor 3D berbasis ligan. Senyawa aktif HDAC4 dan HDAC7 dibuat ke dalam dataset training dan test untuk pembuatan dan validasi model farmakofor 3D berbasis ligan menggunakan LigandScout 4.09.1. Model farmakofor terbaik digunakan untuk penapisan virtual terhadap database herbaldb. Senyawa hit yang diperoleh selanjutnya dilakukan penambatan molekul menggunakan AutoDock4Zn, simulasi dinamika molekuler dan perhitungan nilai MMGB/PBSA menggunakan AMBER12. Berdasarkan hasil validasi model farmakofor 3D berbasis ligan, dipilih model farmakofor terbaik yaitu model 6 dan 10 HDAC4 dan model 1 HDAC7. Berdasarkan hasil penapisan virtual diperoleh 6 senyawa hit yaitu artocarpesin, avicularin, dimboa glucoside, eriodictin, luteolin dan mirabijalone c. Proses simulasi dinamika molekul selama 10ns menunjukan bahwa senyawa yang memiliki aktivitas terbaik yaitu senyawa artocarpesin HDAC4 , mirabijalone c dan eriodictin HDAC7. Asam amino esensial HDAC4 meliputi Asp196, Asp290 dan His198 untuk interaksi ZBG. Asam amino esensial HDAC7 meliputi Asp707, Asp801 dan His709 untuk interaksi ZBG.

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Currently, compounds as the inhibitor of HDAC class IIa are developed as anticancer, antiinflammation, Huntington disease, human papilloma virus and antidiabetes. Inhibitor compounds of HDAC are mainly divided into hydroxamic acid, cyclic peptide, aliphatic acid and benzamide. 3D pharmacophore ligand based approached was used to found inhibitor compounds of HDAC class IIa. Active compounds of HDAC4 and HDAC7 were divided into training and test dataset for build and validation of 3D pharmacophore ligand based models using LigandScout 4.09.1. The best pharmacophore model, was used for virtual screening against herbaldb database. After this steps, hit compounds would be docking using AutoDock4Zn, molecular dynamic simulation, and MMGB PBSA calculation score using AMBER12. Based on the results of 3D model validation pharmacophore based ligand, selected models are models of best pharmacophore 6 and 10 HDAC4 and model 1 HDAC7. Based on the results of virtual screening, 6 hit compounds were obtained such as artocarpesin, avicularin, dimboa glucoside, eriodictin, luteolin and mirabijalone c. Molecular dynamics simulation process for 10ns indicate that the compound has the best activity are artocarpesin for HDAC4, mirabijalone c and eriodictin for HDAC7. Essential amino acids for HDAC4 include Asp196, Asp290 and His198 for ZBG interactions. Essential amino acids for HDAC7 include Asp707, Asp801 and His709 for ZBG interaction."