A theoretical study of repeating sequence in HRP II: A combination of molecular dynamics simulations and O-17 quadrupole coupling tensors

作者：Behzadi Hadi; Esrafili Mehdi D; van der spoel David; Hadipour Nasser L^*; Parsafar Gholamabbas

来源：Biophysical Chemistry, 2008, 137(2-3): 76-80.

DOI：10.1016/j.bpc.2008.07.006

• Nuclear quadrupole resonance
• Density functional theory
• Histidine rich protein II
• MD simulations
• Hydrogen bond

Histidine rich protein II derived pepticle (HRP II 169-182) was investigated by molecular dynamics, MD, simulation and O-17 electric field gradient, EFG, tensor calculations. MD simulation was performed in water at 300 K with alpha-helix initial structure. It was found that peptide loses its initial alpha-helix structure rapidly and is converted to random coil and bent secondary structures. To understand how pepticle structure affects EFG tensors, initial structure and final conformations resulting from MD simulations were used to calculate O-17 EFG tensors of backbone carbonyl oxygens. Calculations were performed using B3LYP method and 6-31+G* basis set. Calculated O-17 EFG tensors were used to evaluate quadrupole coupling constants, QCC, and asymmetry parameters, eta(Q). Difference between the calculated QCC and eta(Q) values revealed how hydrogen-bonding interactions affect EFG tensors at the sites of each oxygen nucleus.

• 出版日期2008-10
• 单位中国科学院