Poster Presenter
Structure-Functional Organization Of The Cardioactive Peptides
Akhmedov N.A., Agayeva L.N., Hajiyeva
Sh.N., Abbasli R.M., Ismailova L.I.
Azerbaijan
One of the basic problems for molecular biophysics is investigating
of the spatial organization of the peptide molecules and their structure-functional
organization. In the represent work the conformational analysis was
applied to investigation of the spatial structure and conformational
possibilities of the peptides, belonging to cardio active peptides
family: Pro-Thr-Phe-Ile-Arg-Phe-NH2,
Lys-Asn-Glu-Phe-Ile-Arg-Phe-NH2, Lys-Ser-Ala-Phe-Val-Arg-Phe-NH2,
Lys-Pro-Ser-Phe-Val-Arg-Phe-NH2, Ala-Gln-Thr-Phe-Val-Arg-Phe-NH2,
Gly-Gln-Thr-Phe-Val-Arg-Phe-NH2, Ser-Pro-Lys-Gln-Asp-Phe-Met-Arg-Phe-NH2
and Asp-Pro-Lys-Gln-Asp-Phe-Met-Arg-Phe-NH2. These molecules responsible
for ensuring the correct functioning of the cardiovascular activity
of the living bodies. The spectrum of biological activities of cardio
active peptides is undoubtedly connected to the conformational flexibility
of these peptides, which is necessary to provide structures complementary
to active sites of various receptors.
The conformational potential energy of each molecule is given as the
sum of the independent contributions of the non-valent, electrostatic,
torsion interactions and hydrogen bonds. The geometrical, energy parameters
and stabilizing interaction energies for stabile conformational states
all of these peptides are determined. The low-energy conformations
of these molecules and the values of the dihedral angles of the main
and side chains are found and the energy of the intra- and inter-residue
interactions is estimated. As a result, only a very restricted set
of low-energy conformations was isolated from a great number of analyzed
combinations of these cardio active peptides. It is found, that possible
structures of the cardio active peptides under physiological conditions
may be described by a set of low-energy conformations. The conformationally
rigid and labile segments of these molecules were revealed. It is
found, that the optimal structures of investigated peptides have turn
on the C- terminal segment Arg-Phe-NH2. The received data allow us
to consider this fragment of cardio active center, provided specify
of their action. Basing the calculation results the simulated analogues
of each peptide molecule are constructed.
At last stage many conformational maps for side chains of amino acid
residues in the low-energy conformations of the natural peptides were
investigated on the basis of a semi empirical method of conformational
analysis. The investigation of the molecular dynamics of each peptide
is of great importance to understanding the mechanism of action these
cardio active peptides with their receptors.
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