Entity

Time filter

Source Type

Tehrān, Iran

Sardari R.R.R.,Payame Noor University | Zarchi S.R.,Payame Noor University | Hajihosseini S.,University of Yazd | Aghili Z.,Food and Drug Laboratories Research Center | And 7 more authors.
International Journal of Electrochemical Science | Year: 2013

Developing some substitutionary ways such as electrochemical methods might be useful in order to follow structural changes of proteins. In this study, the effect of denaturants such as Urea and SDS (sodium dodecyl sulfate) was investigated on Cytochrome C structure, a metalloproteinase with an oxide/redox property. Structural alterations were studied with potentiometer and different spectrometer techniques. Cytochrome C was prepared in 20mM phosphate buffer with pH=7.0. The protein was treated with different concentrations of Urea and SDS. Related absorbance of native and denatured protein were recorded with Cary 50 (UV-Visible) and AVIV-215 (Circular Dichroism) spectrophotometers in range of 200-700 nm. Electrochemical measurements were also recorded with an acetate/Galvan acetate potentiometer device. Cytochrome C was reported to be structurally stabile in 5-8 and 3-9.5mM concentrations of Urea, which were monitored by voltammetry and spectroscopy methods, respectively. The protein was active in high concentration (26mM) of SDS. The concentration of SDS 20mM seems to be sufficient for proper folding of 0.5mM Cytochrome C. It has been concluded that, 40 μM Cytochrome C, crudity, and etc do not impact voltammetry results and it is an independent method for detection of structural changes of proteins. Voltammetry method is more sensitive to small changes in protein structure compared with spectroscopy methods. © 2013 by ESG. Source


Ghiasi R.,Basic Science Faculty | Ghiasi R.,Islamic Azad University at Tehran | Pasdar H.,Islamic Azad University at Tehran
Russian Journal of Physical Chemistry A | Year: 2013

The electronic structure and properties of the platinabenzene and para substituted platinabenzenes have been investigated using the hybrid density functional mpw1pw91 theory. The substituent effect in structure parameters, frontier orbital energies, aromaticity indexes, and hyperpolarizability has been studied. The calculations show that, in all molecules HOMO → LUMO transition makes the major contribution in the most intense electronic transition. © 2013 Pleiades Publishing, Ltd. Source


Pasdar H.,Islamic Azad University at Tehran | Ghiasi R.,Basic Science Faculty | Ajoudani S.,Islamic Azad University at Tehran
Russian Journal of Physical Chemistry A | Year: 2012

The structure and properties of AlN-polycycles were studied by DFT (density functional theory) method. The results of calculations were obtained at B3LYP/6-311G(d, p) level on model species. Topological parameters such as electron density, its Laplacian, kinetic electron energy density, potential electron energy density, and total electron energy density at the ring critical points (RCP) from Bader's 'Atoms in molecules' (AIM) theory were analyzed in detail. These results indicate a good correlation between ρ (3, +1), G(r), H(r), and V(r) averaged values and hardness of AlN-polycycles. The aromaticity of all molecules has been studied by nucleus-independent chemical shift. There is a linear correlation between ΣNICS(0.0) moleculevalues and polarizability. © Pleiades Publishing, Ltd., 2012. Source


Ghlasi R.,Basic Science Faculty | Ghlasi R.,Islamic Azad University at Tehran | Mokarram E.E.,Basic Science Faculty | Mokarram E.E.,Islamic Azad University at Tehran
Russian Journal of Physical Chemistry A | Year: 2011

The structure and bonding of the for C3N3H 2X2Ni(Cp)NO (X = H, F, Cl, Br) and their linkage isomers C3N3H2X2Ni(Cp)ON has been studied by carrying out density functional theory. The bonding nature of NiC bonds has been further explored by means of AIM method and natural bond orbital (NBO) analysis. Nucleus-independent chemical shift (NICS) values calculated at several points above ring center indicate aromaticity of heterocyclic cycle. Also, the effect of substitution (X = F, Cl, Br, CN) in N-heterocyclic carbene on the properties of complex has been shown. © 2011 Pleiades Publishing, Ltd. Source


Ghiasi R.,Basic Science Faculty | Ghiasi R.,Islamic Azad University at Tehran | Ara T.J.,Basic Science Faculty | Ara T.J.,Islamic Azad University at Tehran | And 2 more authors.
Russian Journal of Physical Chemistry A | Year: 2014

The electronic structure and properties of the platinanaphthalenes, and ring-fused B-N platinanaphthalenes isomers have been explored using the hybrid density functional mpw1pw91 theory. The energetic aspect shows that stability of Ptb and Pta isomers are isoenergetic in platinanaphthalenes. On the other hand, BNa1 isomer is the most stable isomer of ring-fused B-N platinanaphthalenes. This is compatible with principles of minimum energy and minimum polarizability in ring-fused B-N platinanaphthalenes. Molecular orbital analysis shows increasing of hardness in ring-fused B-N platinanaphthalenes isomers. Also, electronic spectra analysis indicates that, in all the molecules HOMO-1 → LUMO transition makes the major contribution in most intense electronic transition. © 2014 Pleiades Publishing, Ltd. Source

Discover hidden collaborations