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Homology models of amidase-03 from Bacillus anthracis were constructed using Modeller (9v2). Modeller constructs protein models using
an automated approach for comparative protein structure modeling by the satisfaction of spatial restraints. A template structure of Listeria
monocytogenes bacteriophage PSA endolysin PlyPSA (PDB ID: 1XOV) was selected from protein databank (PDB) using BLASTp with
BLOSUM62 sequence alignment scoring matrix. We generated five models using the Modeller default routine in which initial coordinates
are randomized and evaluated by pseudo-energy parameters. The protein models were validated using PROCHECK and energy minimized
using the steepest descent method in GROMACS 3.2 (flexible SPC water model in cubic box of size 1 Å instead of rigid SPC model). We
used G43a1 force field in GROMACS for energy calculations and the generated structure was subsequently analyzed using the VMD
software for stereo-chemistry, atomic clash and misfolding. A detailed analysis of the amidase-03 model structure from Bacillus anthracis
will provide insight to the molecular design of suitable inhibitors as drug candidates. 相似文献
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AimsProtection of cells from oxidative insult may be possible through direct scavenging of reactive oxygen species, or through stimulation of intracellular antioxidant defense mechanisms by induction of antioxidant gene expression. In this study we investigated the cytoprotective effect of chamomile and elucidated the underlying mechanisms.Main methodsThe cytoprotective effect of chamomile was examined on H2O2-induced cellular stress in RAW 264.7 murine macrophages.Key findingsRAW 264.7 murine macrophages treated with chamomile were protected from cell death caused by H2O2. Treatment with 50 μM H2O2 for 6 h caused significant increase in cellular stress accompanied by cell death in RAW 264.7 macrophages. Pretreatment with chamomile at 10–20 μg/mL for 16 h followed by H2O2 treatment protected the macrophages against cell death. Chamomile exposure significantly increased the expression of antioxidant enzymes viz. heme oxygenase-1 (HO-1), peroxiredoxin-1 (Prx-1), and thioredoxin-1 (Trx-1) in a dose-dependent manner, compared with their respective controls. Chamomile increased nuclear translocation of Nrf2 with increased phosphorylated Nrf2 levels, and binding to the antioxidant response element in the nucleus.SignificanceThese molecular findings for the first time provide insights into the mechanisms underlying the induction of phase 2 enzymes through the Keap1-Nrf2 signaling pathway by chamomile, and provide evidence that chamomile possesses antioxidant and cytoprotective properties. 相似文献
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Ravi Datta Sharma Rajnee Kanwal Andrew M. Lynn Prerna Singh Syed Tazeen Pasha Tasneem Fatma Safdar Jawaid 《Journal of molecular modeling》2013,19(9):3993-4002
Heme containing proteins are associated with peroxidase activity. The proteins like hemoglobin, myoglobins, cytochrome c and micro-peroxidase other than peroxidases have been shown to exhibit weak peroxidase-like activity. This weak peroxidase–like activity in hemoglobin-like molecules is due to heme moiety. We conducted molecular dynamics (MD) studies to decipher the unfolding path of Ba-Glb (a truncated hemoglobin from Bacillus anthracis) and the role of heme moiety to its unfolding path. The similar unfolding path is also observed in vitro by UV/VIS spectroscopy. The data confirmed that the unfolding of Ba-Glb follows a three state process with a meta-stable (intermediate) state between the native and unfolded conformations. The present study is supported by several unfolding parameters like root-mean-square-deviation (RMSD), dictionary of protein secondary structure (DSSP), and free energy landscape. Understanding the structure of hemoglobin like proteins in unicellular dreaded pathogens like B. anthracis will pave way for newer drug discovery targets and in the disease management of anthrax. 相似文献
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Ravi Datta Sharma Andrew M Lynn Pradeep Kumar Sharma Rajnee Safdar Jawaid 《Bioinformation》2009,3(10):430-434
The stability of amidase-03 structure (a cell wall hydrolase protein) from Bacillus anthracis was studied using classical
molecular dynamics (MD) simulation. This protein (GenBank accession number: ) contains an amidase-03
domain which is known to exhibit the catalytic activity of N-acetylmuramoyl-L-alanine amidase (digesting MurNAc-Lalanine
linkage of bacterial cell wall). The amidase-03 enzyme has stability at high temperature due to the core formed by
the combination of several secondary structure elements made of β-sheets. We used root-mean-square-displacement (RMSD)
of the simulated structure from its initial state to demonstrate the unfolding of the enzyme using its secondary structural
elements. Results show that amidase-03 unfolds in transition state ensemble (TSE). The data suggests that α-helices unfold
before β-sheets from the core during simulation. NP_844822相似文献
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