The equilibrium thermodynamics of various peptide sequences


Yasar F.

INTERNATIONAL JOURNAL OF MODERN PHYSICS C, cilt.15, sa.4, ss.583-593, 2004 (SCI İndekslerine Giren Dergi) identifier identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 15 Konu: 4
  • Basım Tarihi: 2004
  • Doi Numarası: 10.1142/s0129183104006066
  • Dergi Adı: INTERNATIONAL JOURNAL OF MODERN PHYSICS C
  • Sayfa Sayıları: ss.583-593

Özet

The equilibrium thermodynamic properties of two peptide sequences of beta-casein in the alpha-helix regions were studied by three-dimensional molecular modeling in vacuum. All the three-dimensional conformations of each peptide sequences were obtained by multicanonical simulations using ECEPP/2 force field and each simulation was started from completely random initial conformation. No a-priori information about ground-state is used in the simulations. In the present study, we calculated the average values of total energy, specific heat, fourth-order cumulant for two peptide sequences of beta-casein as a function of temperature. We observed that the specific heat shows two peaks as a function of temperature for both peptides. Because our sequences have highly helical structure and two peaks in the specific heat, we have also studied the helix-coil transitions to determine these peaks. Our data indeed show these peptides have highly helical structure and better agreement with the results of spectroscopic techniques and other prediction methods.