Molecular dynamics simulation of alpha-melanocyte stimulating hormone
in a water-membrane model interface
Pascutti PG, El-Jaik LJ, Bisch PM, Mundim KC, Ito AS
EUROPEAN BIOPHYSICS JOURNAL WITH BIOPHYSICS LETTERS
28: (6) 499-509 1999
Cited References: 25 Times Cited : 0
Abstract:
The conformation of the tridecapeptide alpha-melanocyte stimulating
hormone in the presence of a double water-membrane interface was studied
by molecular dynamics simulation, using the computational package THOR.
In this program the solvent is represented by a continuous medium with
dielectric constant epsilon, and the interface between different media
is simulated by a surface of discontinuity of the dielectric constant.
The electrostatic image method was used to write down the terms, added
to the force field, that describe the polarisation effects induced in the
interface by the atomic charges. The program was further improved by the
introduction of a second surface, parallel to the first one, to mimic the
membrane. A conformational search using the software Prelude was employed
to find an initial geometry for the peptide in water. The molecular dynamics
simulation performed during 10 ns showed that the peptide structure is
flexible in water, without stabilisation of any preferential conformation.
In the presence of the model membrane, the peptide moved to the medium
representing the interior of the membrane. Inside the low dielectric constant
medium, the structure of the peptide showed a turn in the central sequence
of amino acids and a packed conformation remained stabilised during more
than 7.0 ns of simulation.
Author Keywords:
melanotropic peptides, peptide-lipid interaction, dielectric discontinuity,
molecular dynamics, electrostatic image method
KeyWords Plus:
MELANOTROPIC PEPTIDES, ANALOGS, DESIGN, MSH, PREDICTION, RECEPTOR,
RESIDUES, CLONING
Addresses:
Ito AS, Univ Sao Paulo, Inst Fis, Caixa Postal 66318, BR-05315970 Sao
Paulo, Brazil.
Univ Sao Paulo, Inst Fis, BR-05315970 Sao Paulo, Brazil.
Univ Fed Rio de Janeiro, Inst Biofis Carlos Chagas Filho, BR-21941
Rio De Janeiro, Brazil.
Ctr Brasileiro Pesquisas Fis, Rio De Janeiro, Brazil.
Univ Fed Bahia, BR-41170290 Salvador, BA, Brazil.
Publisher: SPRINGER VERLAG, NEW YORK
IDS Number: 233LQ
ISSN: 0175-7571