Search for: protein-binding
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    Protein fibrillation and nanoparticle interactions: Opportunities and challenges

    , Article Nanoscale ; Volume 5, Issue 7 , Jan , 2013 , Pages 2570-2588 ; 20403364 (ISSN) Mahmoudi, M ; Kalhor, H. R ; Laurent, S ; Lynch, I ; Sharif University of Technology
    Due to their ultra-small size, nanoparticles (NPs) have distinct properties compared with the bulk form of the same materials. These properties are rapidly revolutionizing many areas of medicine and technology. NPs are recognized as promising and powerful tools to fight against the human brain diseases such as multiple sclerosis or Alzheimer's disease. In this review, after an introductory part on the nature of protein fibrillation and the existing approaches for its investigations, the effects of NPs on the fibrillation process have been considered. More specifically, the role of biophysicochemical properties of NPs, which define their affinity for protein monomers, unfolded monomers,... 

    Binding assessment of two arachidonic-based synthetic derivatives of adrenalin with β-lactoglobulin: Molecular modeling and chemometrics approach

    , Article Biophysical Chemistry ; Volume 207 , 2015 , Pages 97-106 ; 03014622 (ISSN) Gholami, S ; Bordbar, A. K ; Akvan, N ; Parastar, H ; Fani, N ; Gretskaya, N. M ; Bezuglov, V. V ; Haertlé, T ; Sharif University of Technology
    Elsevier  2015
    A computational approach to predict the main binding modes of two adrenalin derivatives, arachidonoyl adrenalin (AA-AD) and arachidonoyl noradrenalin (AA-NOR) with the β-lactoglubuline (BLG) as a nano-milk protein carrier is presented and assessed by comparison to the UV-Vis absorption spectroscopic data using chemometric analysis. Analysis of the spectral data matrices by using the multivariate curve resolution-alternating least squares (MCR-ALS) algorithm led to the pure concentration calculation and spectral profiles resolution of the chemical constituents and the apparent equilibrium constants computation. The negative values of entropy and enthalpy changes for both compound indicated... 

    Determination of fentanyl in human plasma by head-space solid-phase microextraction and gas chromatography-mass spectrometry

    , Article Journal of Pharmaceutical and Biomedical Analysis ; Volume 43, Issue 5 , 2007 , Pages 1763-1768 ; 07317085 (ISSN) Bagheri, H ; Es-haghi, A ; Khalilian, F ; Rouini, M. R ; Sharif University of Technology
    A head-space solid-phase microextraction (HS-SPME) method coupled to GC-MS was developed to extract fentanyl from human plasma. The protein binding was reduced by acidification and, eventually, the sample was deproteinized with trichloroacetic acid. The parameters influencing adsorption (extraction time, temperature, pH and salt addition) and desorption (desorption time and temperature) of the analyte on the fibre were investigated and validated for method development. The developed method proved to be rapid, simple, easy and inexpensive and offers high sensitivity and reproducibility. Linear range was obtained from 0.1 ng/ml to 2 μg/ml. The limit of detection was 0.03 ng/ml while an... 

    S494 O-glycosylation site on the SARS-CoV-2 RBD affects the virus affinity to ACE2 and its infectivity; a molecular dynamics study

    , Article Scientific Reports ; Volume 11, Issue 1 , 2021 ; 20452322 (ISSN) Rahnama, S ; Azimzadeh Irani, M ; Amininasab, M ; Ejtehadi, M. R ; Sharif University of Technology
    Nature Research  2021
    SARS-CoV-2 is a strain of Coronavirus family that caused the ongoing pandemic of COVID-19. Several studies showed that the glycosylation of virus spike (S) protein and the Angiotensin-Converting Enzyme 2 (ACE2) receptor on the host cell is critical for the virus infectivity. Molecular Dynamics (MD) simulations were used to explore the role of a novel mutated O-glycosylation site (D494S) on the Receptor Binding Domain (RBD) of S protein. This site was suggested as a key mediator of virus-host interaction. By exploring the dynamics of three O-glycosylated models and the control systems of unglcosylated S4944 and S494D complexes, it was shown that the decoration of S494 with elongated O-glycans... 

    Conservation of statistical results under the reduction of pair-contact interactions to solvation interactions

    , Article Physical Review E - Statistical, Nonlinear, and Soft Matter Physics ; Volume 72, Issue 6 , 2005 ; 15393755 (ISSN) Radja, N.H ; Farzami, R. R ; Ejtehadi, M. R ; Sharif University of Technology
    We show that the hydrophobicity of sequences is the leading term in Miyazawa-Jernigan interactions. Being the source of additive (solvation) terms in pair-contact interactions, they were used to reduce the energy parameters while resulting in a clear vector manipulation of energy. The reduced (additive) potential performs considerably successful in predicting the statistical properties of arbitrary structures. The evaluated designabilities of the structures by both models are highly correlated. Suggesting geometrically nondegenerate vectors (structures) as proteinlike structures, the additive model is a powerful tool for protein design. Moreover, a crossing point in the log-linear diagram of... 

    Temperature: the "ignored" factor at the nanobio interface

    , Article ACS Nano ; Volume 7, Issue 8 , 2013 , Pages 6555-6562 ; 19360851 (ISSN) Mahmoudi, M ; Abdelmonem, A. M ; Behzadi, S ; Clement, J. H ; Dutz, S ; Ejtehadi, M. R ; Hartmann, R ; Kantner, K ; Linne, U ; Maffre, P ; Metzler, S ; Moghadam, M. K ; Pfeiffer, C ; Rezaei, M ; Ruiz-Lozano, P ; Serpooshan, V ; Shokrgozar, M. A ; Nienhaus, G. U ; Parak, W. J ; Sharif University of Technology
    Upon incorporation of nanoparticles (NPs) into the body, they are exposed to biological fluids, and their interaction with the dissolved biomolecules leads to the formation of the so-called protein corona on the surface of the NPs. The composition of the corona plays a crucial role in the biological fate of the NPs. While the effects of various physicochemical parameters on the composition of the corona have been explored in depth, the role of temperature upon its formation has received much less attention. In this work, we have probed the effect of temperature on the protein composition on the surface of a set of NPs with various surface chemistries and electric charges. Our results... 

    Utilization of molecular dynamics simulation coupled with experimental assays to optimize biocompatibility of an electrospun PCL/PVA scaffold

    , Article PLoS ONE ; Volume 12, Issue 1 , 2017 ; 19326203 (ISSN) Sarmadi, M ; Shamloo, A ; Mohseni, M ; Sharif University of Technology
    Public Library of Science  2017
    The main focus of this study is to address the possibility of using molecular dynamics (MD) simulation, as a computational framework, coupled with experimental assays, to optimize composite structures of a particular electrospun scaffold. To this aim, first, MD simulations were performed to obtain an initial theoretical insight into the capability of heterogeneous surfaces for protein adsorption. The surfaces were composed of six different blends of PVA (polyvinyl alcohol) and PCL (polycaprolactone) with completely unlike hydrophobicity. Next, MTT assay was performed on the electrospun scaffolds made from the same percentages of polymers as in MD models to gain an understanding of the... 

    Interaction of water-soluble amino acid Schiff base complexes with bovine serum albumin: Fluorescence and circular dichroism studies

    , Article Spectrochimica Acta - Part A: Molecular and Biomolecular Spectroscopy ; Volume 71, Issue 4 , 2008 , Pages 1617-1622 ; 13861425 (ISSN) Gharagozlou, M ; Mohammadi Boghaei, D ; Sharif University of Technology
    Fluorescence spectroscopy in combination with circular dichroism (CD) spectroscopy were used to investigate the interaction of water-soluble amino acid Schiff base complexes, [Zn(L1,2)(phen)] where phen is 1,10-phenanthroline and H2L1,2 is amino acid Schiff base ligands, with bovine serum albumin (BSA) under the physiological conditions in phosphate buffer solution adjusted to pH 7.0. The quenching mechanism of fluorescence was suggested as static quenching according to the Stern-Volmer equation. Quenching constants were determined using the Stern-Volmer equation to provide a measure of the binding affinity between amino acid Schiff base complexes and BSA. The thermodynamic parameters ΔG, ΔH... 

    Personalised deposition maps for micro- and nanoparticles targeting an atherosclerotic plaque: attributions to the receptor-mediated adsorption on the inflamed endothelial cells

    , Article Biomechanics and Modeling in Mechanobiology ; Volume 18, Issue 3 , 2019 , Pages 813-828 ; 16177959 (ISSN) Shamloo, A ; Forouzandehmehr, M ; Sharif University of Technology
    Springer Verlag  2019
    Endothelial inflammation as a prominent precursor to atherosclerosis elicits a distinct pathological surface expression of particular vascular proteins. To exhibit a site-specific behaviour, micro- and nanoparticles, as carriers of therapeutics or imaging agents, can distinguish and use these proteins as targeted docking sites. Here, a computational patient-specific model capturing the exclusive luminal qualities has been developed to study the transport and adsorption of particles decorated with proper antibodies over an atherosclerotic plaque located in the LAD artery of the patient. Particles, in nano- and micron sizes, have been decorated with Sialyl Lewisx (sLex), P-selectin aptamer... 

    Protein G selects two binding sites for carbon nanotube with dissimilar behavior; a molecular dynamics study

    , Article Journal of Molecular Graphics and Modelling ; Volume 87 , 2019 , Pages 257-267 ; 10933263 (ISSN) Ebrahim Habibi, M. B ; Ghobeh, M ; Aghakhani Mahyari, F ; Rafii Tabar, H ; Sasanpour, P ; Sharif University of Technology
    Elsevier Inc  2019
    Background: Study of nanostructure-protein interaction for development of various types of nano-devices is very essential. Among carbon nanostructures, carbon nanotube (CNT) provides a suitable platform for functionalization by proteins. Previous studies have confirmed that the CNT induces changes in the protein structure. Methods: Molecular dynamics (MD) simulation study was employed to illustrate the changes occurring in the protein G (PGB) in the presence of a CNT. In order to predict the PGB surface patches for the CNT, Autodock tools were utilized. Results: Docking results indicate the presence of two different surface patches with diverse amino acids: the dominant polar residues in the... 

    Development of a novel nano-sized anti-VEGFA nanobody with enhanced physicochemical and pharmacokinetic properties

    , Article Artificial Cells, Nanomedicine and Biotechnology ; Volume 46, Issue 7 , 2018 , Pages 1402-1414 ; 21691401 (ISSN) Khodabakhsh, F ; Norouzian, D ; Vaziri, B ; Ahangari Cohan, R ; Sardari, S ; Mahboudi, F ; Behdani, M ; Mansouri, K ; Mehdizadeh, A ; Sharif University of Technology
    Since physiological and pathological processes occur at nano-environments, nanotechnology has considered as an efficient tool for designing of next generation specific biomolecules with enhanced pharmacodynamic and pharmacodynamic properties. In the current investigation, by control of the size and hydrodynamic volume at the nanoscale, for the first time, physicochemical and pharmacokinetic properties of an anti-VEGFA nanobody was remarkably improved by attachment of a Proline-Alanine-Serine (PAS) rich sequence. The results elucidated unexpected impressive effects of PAS sequence on physicochemical properties especially on size, hydrodynamics radius, and even solubility of nanobody. CD...