Header menu link for other important links
X
Structure and dynamics of H2O vis-á-vis phenylalanine recognition at a DPPC lipid membrane via interfacial H-bond types: Insights from polarized FT-IRRAS and ADMP simulations
Nivarthi G. Ramesh,
Published in American Institute of Physics Inc.
2015
PMID: 25591372
Volume: 142
   
Issue: 2
Abstract
Preferential and enantioselective interactions of l-/d-Phenylalanine (l-Phe and d-Phe) and butoxycarbonyl-protected l-/d-Phenylalanine (LPA and DPA) as guest with 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (l-DPPC) as host were tapped by using real time Fourier transform infrared reflection absorption spectroscopy (FT-IRRAS). Polarization-modulated FT-IRRAS of DPPC monolayers above the phenylalanine modified subphases depicted fine structure/conformation differences under considerations of controlled 2D surface pressure. Selective molecular recognition of d-enantiomer over l-enantiomer driven by the DPPC head group via H-bonding and electrostatic interactions was evident spectroscopically. Accordingly, binding constants (K) of 145, 346, 28, and 56 M-1 for LPA, DPA, l-Phe, and d-Phe, respectively, were estimated. The real time FT-IRRAS water bands were strictly conformation sensitive. The effect of micro-solvation on the structure and stability of the 1:1 diastereomeric l-lipidâ?, LPA/DPA and l-lipidâ?, (l/d)-Phe adducts was investigated with the aid of Atom-centered Density Matrix Propagation (ADMP), a first principle quantum mechanical molecular dynamics approach. The phosphodiester fragment was the primary site of hydration where specific solvent interactions were simulated through single- and triple- "water-phosphate" interactions, as water cluster's "tetrahedral dice" to a "trimeric motif" transformation as a partial de-clusterization was evident. Under all the hydration patterns considered in both static and dynamic descriptions of density functional theory, l-lipid/d-amino acid enantiomer adducts continued to be stable structures while in dynamic systems, water rearranged without getting "squeezed-out" in the process of recognition. In spite of the challenging computational realm of this multiscale problem, the ADMP simulated molecular interactions complying with polarized vibrational spectroscopy unraveled a novel route to chiral recognition and interfacial water structure. © 2015 AIP Publishing LLC.
About the journal
JournalData powered by TypesetJournal of Chemical Physics
PublisherData powered by TypesetAmerican Institute of Physics Inc.
ISSN00219606
Open AccessNo
Concepts (39)
  •  related image
    Absorption spectroscopy
  •  related image
    Amino acids
  •  related image
    Chemical bonds
  •  related image
    Computation theory
  •  related image
    Enantiomers
  •  related image
    Hydration
  •  related image
    Molecular dynamics
  •  related image
    Pattern recognition systems
  •  related image
    Quantum theory
  •  related image
    1 ,2-DIPALMITOYL-SN-GLYCERO-3-PHOSPHOCHOLINE
  •  related image
    ENANTIOSELECTIVE INTERACTIONS
  •  related image
    Fourier transform infra reds
  •  related image
    INTERFACIAL WATER STRUCTURE
  •  related image
    MULTISCALE PROBLEM
  •  related image
    POLARIZATION-MODULATED
  •  related image
    Solvent interactions
  •  related image
    Structure and dynamics
  •  related image
    Density functional theory
  •  related image
    Dipalmitoylphosphatidylcholine
  •  related image
    Phenylalanine
  •  related image
    Phosphate
  •  related image
    Solvent
  •  related image
    Water
  •  related image
    Cell membrane
  •  related image
    Chemical phenomena
  •  related image
    Chemistry
  •  related image
    Conformation
  •  related image
    Hydrogen bond
  •  related image
    Infrared spectroscopy
  •  related image
    Static electricity
  •  related image
    Thermodynamics
  •  related image
    1,2-dipalmitoylphosphatidylcholine
  •  related image
    Hydrogen bonding
  •  related image
    Hydrophobic and hydrophilic interactions
  •  related image
    Molecular conformation
  •  related image
    Molecular dynamics simulation
  •  related image
    Phosphates
  •  related image
    Solvents
  •  related image
    Spectroscopy, fourier transform infrared