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

A new decavanadate polyoxovanadate nanocluster: synthesis, characterization and rapid adsorption of methylene blue

<p>A new decavanadate polyoxovanadate nanocluster, [2-ampH]₆[V₁₀O₂₈]∙2H₂O (<b>1</b>), was synthesized through reaction between ammonium vanadate and 2-aminopyridine at pH = 2. Nanocluster <b>1</b> was characterized by IR, elemental analysis, and X-ray crystallography. <b>1</b> was found to adsorb and desorb dyes and may have widespread application in wastewater treatment. The utility of <b>1</b> for adsorption of methylene blue was studied. The adsorbed dyes can be easily desorbed, and <b>1</b> has full efficiency after five cycles.</p