Evaluation of Gox^• scavenging rate by curcumin based on ESR results.

<p>The ESR spectra were followed after addition of different concentrations of curcumin (10 µM •; 20 µM ▪; 40 µM ▴). Inset: ESR spectra of 10 µM galvinoxyl radicals in different conditions. a) before addition of curcumin, b) 10 min after addition of 10 µM curcumin, c) 10 min after addition of 40 µM curcumin.</p

Effect of curcumin on viability of L-6 myoblasts exposed to cumene hydroperoxide (CHP).

<p>After a 30 min treatment of cells with different concentrations of curcumin (0, 1 and 5.0 µM) the cells were induced with 5 µl (1∶100) CHP. Viability was measured by the MTT assay.</p

In situ analysis of intracellular ROS.

<p>A) All samples were first incubated (30 min) with different concentration of curcumin (a, 0.0; b, 0.1; c, 0.25; d, 0.5; e, 1.0; f, 2.0; g, 4.0 µM), then the DCF fluorescence intensity changes were monitored by the addition of the ROS stimulating agent cumene hydroperoxide (CHP). In the absence of CHP, no change in DCF fluorescence intensity was seen with time; however, it started increasing in presence of CHP. B) The principle of the intracellular ROS protection activity of curcumin. Curcumin diffuses easily into the cells prevents ROS production, thereby preventing oxidation of DCFH₂ and the formation of the fluorescent DCF product.</p

Chemical structures of galvinoxyl radical.

<p>Chemical structures of galvinoxyl radical.</p

Chemical structures of curcumin, α-tocopherol, and trolox.

<p>Chemical structures of curcumin, α-tocopherol, and trolox.</p

Comparative physical properties of curcumin, trolox and α-tocopherol.

<p>*The parameters were obtained from ChemBank (<a href="http://chembank.broadinstitute.org/" target="_blank">http://chembank.broadinstitute.org/</a>).</p><p>a: total surface area (SA_tot), b: polar surface area (SA_pol), c: relative polar surface area (SA_pol/SA_tot).</p

Interaction mechanism of insulin with ZnO nanoparticles by replica exchange molecular dynamics simulation

<p>The interaction of ZnO nanoparticles with biological molecules such as proteins is one of the most important and challenging problems in molecular biology. Molecular dynamics (MD) simulations are useful technique for understating the mechanism of various interactions of proteins and nanoparticles. In the present work, the interaction mechanism of insulin with ZnO nanoparticles was studied. Simulation methods including MD and replica exchange molecular dynamics (REMD) and their conditions were surveyed. According to the results obtained by REMD simulation, it was found that insulin interacts with ZnO nanoparticle surface via its polar and charged amino acids. Unfolding insulin at ZnO nanoparticle surface, the terminal parts of its chains play the main role. Due to the linkage between chain of insulin and chain of disulfide bonds, opposite directional movements of N terminal part of chain A (toward nanoparticle surface) and N termini of chain B (toward solution) make insulin unfolding. In unfolding of insulin at this condition, its helix structures convert to random coils at terminal parts chains.</p

2D kernel densities of PCA for the PHD2 species unfolding states.

<p>The most fold state resides in left side of panels and the most unfold states reside in right side of panels. The densities of a-PHD2, f-PHD2 and fh-PHD2 are depicted in panel A, B and C respectively. The panels are the 2D kernel density maps for the principal components 1, 2. Principal components are computed by utilizing the properties space used to build the <i>d</i> metric. Horizontal and vertical dimensions indicate first and second principal components respectively. The contour levels indicate the density. Darker region is the most populated region.</p

Comparing the percentage of PHD2 species contribution to each variable during partial unfolding.

<p>The contribution of PHD2 species to each property’s information content is represented in percent. p, np note polar or non-polar parts of the molecule. ASA stands for accessible surface area, t and s stand for total and side chain respectively. Rgyr stands for radius of gyration. Dpm notes the dipole moment. W stands for tryptophan residue. Docking site and active site lumen are the ASA of corresponding parts of PHD2. l.E% and l.H% stand for the amount of strand or helix structure melting respectively. l.C% notes the amount of appeared coiled structure.</p

The results of structures clustering by Affinity propagation (AP) method for PHD2 species.

<p>The most fold cluster resides in left side of panels and the most unfold clusters reside in right side of panels. The structures’ clusters of a-PHD2, f-PHD2 and fh-PHD2 are depicted in panel A, B and C respectively. The panels are the results of affinity propagation clustering method. After reducing the dimensionality of the properties space used to build the <i>d</i> metric by n-MDS, AP clustering is performed. X and Y axes are the output vectors of n-MDS. Points represent structures in AP method. Clusters (states) are declared with different colors.</p