35 research outputs found
How to Find Chemical Information: A Guide for Practicing Chemists, Educators, and Students, Third Edition By Robert E. Maizell (Technology Information Consultants, New Haven). Wiley-Interscience, John Wiley and Sons, New York, NY. 1998. xxiii + 515 pp. 16 × 23.5 cm. $64.95. ISBN 0-471-12579-2.
Handbook of Reagents for Organic Synthesis; Oxidizing and Reducing Agents Edited by Steven D. Burke (The University of Wisconsin at Madison) and Rick L. Danheiser (Massachusetts Institute of Technology). John Wiley and Sons, New York, NY. 1999. xii + 550 pp. 21 × 37.5 cm. $115.00. ISBN 0-471-97926-0.
Conformationally-Dependent Free Energies of Solvation. An Explanation for the Large Group-Transfer Potential of Acetylcarnitine
Crystal structures of isomeric (2,6-dioxacyclohexyl)phenols: models for preassociation complexes in acid-catalyzed solvolysis of acetals
Mo1691 Lanthionine Synthetase C-Like Receptor 2 (LANCL2): A Novel Therapeutic Target for Inflammatory Bowel Disease
Dendritic Amphiphiles Strongly Affect the Biophysical Properties of DPPC Bilayer Membranes
Molecular dynamics (MD) simulations were used to gain
insight on
the molecular interactions in a model biological membrane comprised
of a bilayer with DPPC (dipalmitoylphosphotidylcholine) and antimicrobial
dendritic amphiphile molecules [RCONHCÂ(CH<sub>2</sub>CH<sub>2</sub>COOH)<sub>3</sub>, where <i>R</i> is the saturated hydrocarbon
tail (<i>R</i> = <i>n</i>-C<sub><i>n</i></sub>H<sub>2<i>n</i>+1</sub>), to be abbreviated as 3CAmn].
This study analyzes different biophysical properties of the equilibrated
mixed bilayers, at 300 and 325 K, to determine how the presence of
the 3CAmn, in varying concentrations and tail lengths, affects the
lipid bilayer. Lipid tail order parameter data, bilayer thickness
trends, and qualitative lipid tail tilt observations suggest that
a molar ratio of 0.2 3CAm19/DPPC is sufficient to induce a phase transition
in the bilayer from gel to liquid crystalline at 300 K. These results
also imply that the phase transition temperature of the mixed bilayer
decreases upon incorporation of higher concentrations of 3CAm19. Hydrogen
bonding takes place between the 3CAmn and DPPC at specific sites,
as evidenced by the radial distribution function. Increased hydrogen
bonding and the smaller headgroup size of the 3CAmn molecule result
in a decrease in the total lateral area with higher concentrations
of 3CAm19. Diffusion constants of 3CAmn varied with concentration
and tail length; diffusion constants of DPPC and 3CAm19 increased
with increasing 3CAm19 concentration at 300 K and shorter 3CAmn tails
had higher diffusion constants at both temperatures. These computational
studies provide a comprehensive understanding of the biophysical changes
to model biological membranes by the association of 3CAmn