scholarly journals PENENTUAN SISI AKTIF SELULASE ASPERGILLUS NIGER DENGAN DOCKING LIGAN

2014 ◽  
Vol 16 (2) ◽  
pp. 94-100 ◽  
Author(s):  
Tigor Nauli
Keyword(s):  
Aspergillus Niger ◽  
Active Site ◽  
Molecular Conformation ◽  
Catalytic Domain ◽  
Binding Free Energy ◽  
Docking Simulation ◽  
Optimization Approach ◽  
Calculation Results ◽  
Substrate Binding Domain ◽  
Specific Metal

Letak dari sisi aktif selulase Aspergillus niger, yang akan menentukan aktivitas katalitiknya, dapat diketahui melalui komputasi. Sebuah ligan selobiosa dimodelkan untuk dapat melakukan simulasi docking pada molekul selulase yang telah diketahui struktur kristalnya. Melalui kalkulasi energi ikatan dan pendekatan optimasi memakai algoritma genetik Lamarckian, dapat dipilih konformasi molekul yang menunjukkan adanya daerah tertentu dengan energi terendah. Struktur yang memiliki daerah semacam ini dianggap mewakili konfigurasi terbaik terikatnya ligan pada sisi aktif yang dicari.Hasil perhitungan memperlihatkan bahwa tekukan protein yang membentuk celah konkaf diantara dua kelompok struktur b-sheet yang saling berlawanan arah pada molekul selulase merupakan sisi aktif dari enzim tersebut. Ligan dapat terikat disana melalui interaksi hidrofilik dengan residu asparagin (Asn20), serin (Ser111), dan glutamin (Gln158). Di salah satu ujung sisi aktif selulase terdapat residu aspartat (Asp99) dan glutamat (Glu116, Glu204) yang akan mempengaruhi aksi katalitik dari enzim selulase apabila residu-residu ini terikat oleh ion-ion divalen.Sisi aktif selulase ini merupakan gabungan dari domain pengikat substrat dan domain katalitik. Penambahan ion logam yang tepat pada sisi aktif enzim selulase Aspergillus niger dapat meningkatkan aktivitas spesifiknya.Kata kunci:docking, ligan, selulase, sisi ikatan, substrat The active site of cellulase from Aspergillus niger that affects the enzyme activity can be searched by computational methods. A ligand of cellobiose is modelled to perform docking simulation to cellulase with known crystal structure. By calculating the binding free energy and optimization approach using Lamarckian's genetic algorithm, a molecular conformation that has a region with the lowest energy value can be selected. The molecule structure with such region represents the best configuration of ligand bound to the active site.The calculation results that the concave cleft formed by protein folding of two anti-parallel b-sheet structures is the active site of the enzyme. A ligand would bind to the site through hydrophilic interactions with asparagine (Asn20), serine (Ser111), and glutamine (Gln158) residues. The aspartic acid (Asp99) and glutamic acid (Glu116, Glu204) residues that reside in one end of the active site determine the catalytic actions of the enzyme when they are binding with some metal ions.It is shown that the active site of this cellulase has substrate-binding domain and catalytic domain together. The introduction of specific metal ions to the active site of Asperillus niger cellulase will increase its specific activity.Keywords: binding site, cellulase, docking, ligand, substrate

Novel Piperazine Amides of Cinnamic Acid Derivatives as Tyrosinase Inhibitors

2018 ◽  
Vol 16 (1) ◽  
pp. 36-44 ◽  
Author(s):  
Zehra Tuğçe Gür ◽  
Fatma Sezer Şenol ◽  
Suhaib Shekfeh ◽  
İlkay Erdoğan Orhan ◽  
Erden Banoğlu ◽  
...  
Keyword(s):  
Cinnamic Acid ◽  
Active Site ◽  
Agaricus Bisporus ◽  
Biological Activities ◽  
Docking Simulation ◽  
Cinnamic Acid Derivatives ◽  
In Silico Docking ◽  
Amide Derivatives ◽  
Tyrosinase Inhibitors ◽  
Further Development

Background: A series of novel cinnamic acid piperazine amide derivatives has been designed and synthesized, and their biological activities were also evaluated as potential tyrosinase inhibitors. Methods: Compounds 9, 11 and 17 showed the most potent biological activity (IC50 = 66.5, 61.1 and 66 µM, respectively). In silico docking simulation was performed to position compound 11 into the Agaricus bisporus mushroom tyrosinase’s active site to determine the putative binding interactions. Results and Conclusion: The results indicated that compound 11 could serve as a promising lead compound for further development of potent tyrosinase inhibitors.

scholarly journals Toward the Identification of Potential α-Ketoamide Covalent Inhibitors for SARS-CoV-2 Main Protease: Fragment-Based Drug Design and MM-PBSA Calculations

Processes ◽  
2021 ◽  
Vol 9 (6) ◽  
pp. 1004
Author(s):  
Mahmoud A. El Hassab ◽  
Mohamed Fares ◽  
Mohammed K. Abdel-Hamid Amin ◽  
Sara T. Al-Rashood ◽  
Amal Alharbi ◽  
...  
Keyword(s):  
Drug Design ◽  
Active Site ◽  
Binding Free Energy ◽  
Stable Complex ◽  
Active Site Residues ◽  
Structure Based Drug Design ◽  
Enzyme Active Site ◽  
Potential Inhibitor ◽  
Main Protease ◽  
Covalent Docking

Since December 2019, the world has been facing the outbreak of the SARS-CoV-2 pandemic that has infected more than 149 million and killed 3.1 million people by 27 April 2021, according to WHO statistics. Safety measures and precautions taken by many countries seem insufficient, especially with no specific approved drugs against the virus. This has created an urgent need to fast track the development of new medication against the virus in order to alleviate the problem and meet public expectations. The SARS-CoV-2 3CL main protease (Mpro) is one of the most attractive targets in the virus life cycle, which is responsible for the processing of the viral polyprotein and is a key for the ribosomal translation of the SARS-CoV-2 genome. In this work, we targeted this enzyme through a structure-based drug design (SBDD) protocol, which aimed at the design of a new potential inhibitor for Mpro. The protocol involves three major steps: fragment-based drug design (FBDD), covalent docking and molecular dynamics (MD) simulation with the calculation of the designed molecule binding free energy at a high level of theory. The FBDD step identified five molecular fragments, which were linked via a suitable carbon linker, to construct our designed compound RMH148. The mode of binding and initial interactions between RMH148 and the enzyme active site was established in the second step of our protocol via covalent docking. The final step involved the use of MD simulations to test for the stability of the docked RMH148 into the Mpro active site and included precise calculations for potential interactions with active site residues and binding free energies. The results introduced RMH148 as a potential inhibitor for the SARS-CoV-2 Mpro enzyme, which was able to achieve various interactions with the enzyme and forms a highly stable complex at the active site even better than the co-crystalized reference.

scholarly journals The Catalytic Domain ofEscherichia coliLon Protease Has a Unique Fold and a Ser-Lys Dyad in the Active Site

2003 ◽  
Vol 279 (9) ◽  
pp. 8140-8148 ◽  
Author(s):  
Istvan Botos ◽  
Edward E. Melnikov ◽  
Scott Cherry ◽  
Joseph E. Tropea ◽  
Anna G. Khalatova ◽  
...  
Keyword(s):  
Active Site ◽  
Catalytic Domain

scholarly journals Myelin 2′,3′-Cyclic Nucleotide 3′-Phosphodiesterase: Active-Site Ligand Binding and Molecular Conformation

PLoS ONE ◽  
2012 ◽  
Vol 7 (2) ◽  
pp. e32336 ◽  
Author(s):  
Matti Myllykoski ◽  
Arne Raasakka ◽  
Huijong Han ◽  
Petri Kursula
Keyword(s):  
Ligand Binding ◽  
Active Site ◽  
Cyclic Nucleotide ◽  
Molecular Conformation

Enzyme activity enhancement of chondroitinase ABC I from Proteus vulgaris by site-directed mutagenesis

RSC Advances ◽  
2015 ◽  
Vol 5 (93) ◽  
pp. 76040-76047 ◽  
Author(s):  
Zhenya Chen ◽  
Ye Li ◽  
Yue Feng ◽  
Liang Chen ◽  
Qipeng Yuan
Keyword(s):  
Active Site ◽  
Simulation Analysis ◽  
Docking Simulation ◽  
Site Directed Mutagenesis ◽  
Directed Mutagenesis ◽  
Wild Type ◽  
Proteus Vulgaris ◽  
Molecular Docking Simulation ◽  
Activity Enhancement ◽  
First Time

Arg660 was found as a new active site and Asn795Ala and Trp818Ala mutants showed higher activities than the wild type based on molecular docking simulation analysis for the first time.

Crystal structure of acetylxylan esterase from Caldanaerobacter subterraneus subsp. tengcongensis

2021 ◽  
Vol 77 (11) ◽  
Author(s):  
Kohei Sasamoto ◽  
Tomoki Himiyama ◽  
Kunihiko Moriyoshi ◽  
Takashi Ohmoto ◽  
Koichi Uegaki ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Cellulose Acetate ◽  
Electron Density ◽  
Active Site ◽  
Catalytic Domain ◽  
Crystal Packing ◽  
Signal Sequence ◽  
Industrial Applications ◽  
Side Chain ◽  
Active Site Conformation

The acetylxylan esterases (AXEs) classified into carbohydrate esterase family 4 (CE4) are metalloenzymes that catalyze the deacetylation of acetylated carbohydrates. AXE from Caldanaerobacter subterraneus subsp. tengcongensis (TTE0866), which belongs to CE4, is composed of three parts: a signal sequence (residues 1–22), an N-terminal region (NTR; residues 23–135) and a catalytic domain (residues 136–324). TTE0866 catalyzes the deacetylation of highly substituted cellulose acetate and is expected to be useful for industrial applications in the reuse of resources. In this study, the crystal structure of TTE0866 (residues 23–324) was successfully determined. The crystal diffracted to 1.9 Å resolution and belonged to space group I212121. The catalytic domain (residues 136–321) exhibited a (β/α)7-barrel topology. However, electron density was not observed for the NTR (residues 23–135). The crystal packing revealed the presence of an intermolecular space without observable electron density, indicating that the NTR occupies this space without a defined conformation or was truncated during the crystallization process. Although the active-site conformation of TTE0866 was found to be highly similar to those of other CE4 enzymes, the orientation of its Trp264 side chain near the active site was clearly distinct. The unique orientation of the Trp264 side chain formed a different-shaped cavity within TTE0866, which may contribute to its reactivity towards highly substituted cellulose acetate.

Structural insights into dihydroxylation of terephthalate, a product of polyethylene terephthalate degradation

2022 ◽  
Author(s):  
Jai Krishna Mahto ◽  
Neetu Neetu ◽  
Monica Sharma ◽  
Monika Dubey ◽  
Bhanu Prakash Vellanki ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Substrate Specificity ◽  
Polyethylene Terephthalate ◽  
Active Site ◽  
Catalytic Domain ◽  
Structural Features ◽  
Comamonas Testosteroni ◽  
Plastic Pollution ◽  
Microbial Utilization ◽  
Steady State Kinetics

Biodegradation of terephthalate (TPA) is a highly desired catabolic process for the bacterial utilization of this Polyethylene terephthalate (PET) depolymerization product, but to date, the structure of terephthalate dioxygenase (TPDO), a Rieske oxygenase (RO) that catalyzes the dihydroxylation of TPA to a cis -diol is unavailable. In this study, we characterized the steady-state kinetics and first crystal structure of TPDO from Comamonas testosteroni KF1 (TPDO KF1 ). The TPDO KF1 exhibited the substrate specificity for TPA ( k cat / K m = 57 ± 9 mM −1 s −1 ). The TPDO KF1 structure harbors characteristics RO features as well as a unique catalytic domain that rationalizes the enzyme’s function. The docking and mutagenesis studies reveal that its substrate specificity to TPA is mediated by Arg309 and Arg390 residues, two residues positioned on opposite faces of the active site. Additionally, residue Gln300 is also proven to be crucial for the activity, its substitution to alanine decreases the activity ( k cat ) by 80%. Together, this study delineates the structural features that dictate the substrate recognition and specificity of TPDO. Importance The global plastic pollution has become the most pressing environmental issue. Recent studies on enzymes depolymerizing polyethylene terephthalate plastic into terephthalate (TPA) show some potential in tackling this. Microbial utilization of this released product, TPA is an emerging and promising strategy for waste-to-value creation. Research from the last decade has discovered terephthalate dioxygenase (TPDO), as being responsible for initiating the enzymatic degradation of TPA in a few Gram-negative and Gram-positive bacteria. Here, we have determined the crystal structure of TPDO from Comamonas testosteroni KF1 and revealed that it possesses a unique catalytic domain featuring two basic residues in the active site to recognize TPA. Biochemical and mutagenesis studies demonstrated the crucial residues responsible for the substrate specificity of this enzyme.

Exploration of Umbelliferone Based Derivatives as Potent MAO Inhibitors: Dry vs. Wet Lab Evaluation

2019 ◽  
Vol 18 (21) ◽  
pp. 1857-1871 ◽  
Author(s):  
Priyanka Dhiman ◽  
Neelam Malik ◽  
Anurag Khatkar
Keyword(s):  
Active Site ◽  
Docking Simulation ◽  
Selectivity Index ◽  
Drug Candidates ◽  
Ic50 Value ◽  
Spectrophotometric Titrations ◽  
Wet Lab ◽  
Inhibitory Potential ◽  
Anxiety Depression ◽  
The Impact

Background: Monoamine oxidase inhibitors are potential drug candidates within therapeutics of different neuropsychological and neurodegenerative disorders including anxiety, depression and Parkinson’s disease. Objective: We investigated the MAO inhibitory effects of the umbelliferone based derivatives for the treatment of neurological disorders. The potential antioxidant effects of the derivatives were evaluated by DPPH and H2O2 scavenging methods. Method: A series of different umbelliferone derivatives was designed and synthesized, and the derivatives were screened for hMAO-A and hMAO-B inhibition. Moreover, the mechanistic insight for enzyme- compound infractions was achieved by docking simulation. The antioxidant potential was dually assessed by two spectrophotometric titrations methods. Results: Compound 5 with bromo 5-bromo-isatin exhibited a remarkable hMAO-A inhibitory potential (7.473±0.035 µM and the selectivity index of 0.14) revealing the impact of hybrid coumarin and 5- bromo-2-oxoindolin-3-yl ring with hydrazine linker on the hMAO-A active site. Compound 13 exhibited significant hMAO-B inhibition with an IC50 value of 10.32±0.044µM with an exceptional selectivity index of 8.55. Incorporation of 2-hydroxy-2-phenylacetate moiety on 2-oxo-2H-chromen ring led the important binding infractions within the hMAO active site. Conclusion: Our findings revealed a good correlation between experimental MAO inhibition and docking score by computational studies. Notably, the compounds with remarkable MAO inhibitory potential were also observed as potential antioxidants.

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