Electrostatic Potential from High-Resolution X-Ray Diffraction. Application to a Pseudo-Peptide Molecule *
نویسندگان
چکیده
models [1] of the charge density derived from X-ray experiments are available. Starting with a multipolar model of the valence deformation density, Stewart was the first to give an analytical expression of the electrostatic potential in this case [2]; his first papers are based mainly on reciprocal-space calculations by Fourier transformation of [ H 2 ] ^weighted structure factors. Direct calculations are described in X.M. He's Ph.D. thesis from the University of Pittsburgh (1984, USA). We have applied [3] this formalism to the Hansen-Coppens [1 d] multipolar model of an atomic electron density,
منابع مشابه
Electrostatic complementarity in an aldose reductase complex from ultra-high-resolution crystallography and first-principles calculations.
The electron density and electrostatic potential in an aldose reductase holoenzyme complex have been studied by density functional theory (DFT) and diffraction methods. Aldose reductase is involved in the reduction of glucose in the polyol pathway by using NADPH as a cofactor. The ultra-high resolution of the diffraction data and the low thermal-displacement parameters of the structure allow ac...
متن کاملX-ray Charge-Dens Study of 5-Chloro-8-hydroxy-6-methyloaphthalene-l.4-dione: A Hydroxynaphthoquinone Derivative
The X-ray charge density analysis of a hydroxynaphthoquinnne derivative was obtained by multipolar Hansen-Coppens formalism refinement through high resolution X-ray diffraction data at 100(1) K. The molecularproperties of the title compound resulted from the combined experimental and the quantum theory of atoms inmolecules (QTAIM) studies. The topological properties of the covalent bonds and of...
متن کاملTheoretical and experimental electrostatic potential around the m-nitrophenol molecule.
This work concerns a comparison of experimental and theoretical results of the electron charge density distribution and the electrostatic potential around the m-nitrophenol molecule (m-NPH) known for its interesting physical characteristics. The molecular experimental results have been obtained from a high-resolution X-ray diffraction study. Theoretical investigations were performed using the D...
متن کاملApplication of Modified LECA in Removing Nickel from Wastewater
In the present study, lightweight expanded clay aggregate (LECA) coated with iron oxide was investigated as a low cost sorbent to remove from wastewater. Iron oxide coated LECA (IOCL) as a new sorbent was tested for its efficiency as sorbent using operational parameters such as contact time, the initial pH of the solutions, and sorbent dosage concentration in batch systems. The adsorption cha...
متن کاملConvergent chemical synthesis and high-resolution x-ray structure of human lysozyme.
In this article, we report the total chemical synthesis of human lysozyme. Lysozyme serves as a widespread model system in various fields of biochemical research, including protein folding, enzyme catalysis, and amyloidogenesis. The 130-aa wild-type polypeptide chain of the human enzyme was assembled from four polypeptide segments by using native chemical ligation in a fully convergent fashion....
متن کامل