Molecular dynamics simulation restrained

Example If a drug molecule interacts with a receptor molecule through hydrogen bonds, then yon might restrain the distance between the donor and acceptor atoms involved in the hydrogen bonds. During a molecular dynamics simulation, these atoms would slay near an ideal value, while the rest of the molecular system fully relaxes. 

Example Molecular dynamics simulations of selected portions of proteins can demonstrate the motion of an amino acid sequence while fixing the terminal residues. These simulations can probe the motion of an alpha helix, keeping the ends restrained, as occurs n atiirally m transmembrane proteins. You can also investigate the conformations of loops with fixed endpoints. 

The first molecular dynamics simulations of a lipid bilayer which used an explicit representation of all the molecules was performed by van der Ploeg and Berendsen in 1982 [van dei Ploeg and Berendsen 1982]. Their simulation contained 32 decanoate molecules arranged in two layers of sixteen molecules each. Periodic boundary conditions were employed and a xmited atom force potential was used to model the interactions. The head groups were restrained using a harmonic potential of the form ... 

A particularly important application of molecular dynamics, often in conjunction with the simulated annealing method, is in the refinement of X-ray and NMR data to determine the three-dimensional structures of large biological molecules such as proteins. The aim of such refinement is to determine the conformation (or conformations) that best explain the experimental data. A modified form of molecular dynamics called restrained moleculai dynarrdcs is usually used in which additional terms, called penalty functions, are added tc the potential energy function. These extra terms have the effect of penalising conformations... 

The most definitive proof of p-sheet structure requires the determination of the three-dimensional solution structure of the peptide. For the calculation of such structures one requires the accurate determination of coupling constants by DQF-COSY experiments which give backbone dihedral restraints and through-space connectivities (ROESY or NOESY experiments) which give rise to distance restraints. A combination of these restraints allows the calculation of the three-dimensional structure of the peptide using restrained molecular dynamics simulations. Utilizing this methodology, the three-dimensional structures of a number of cyclic peptides have been solved.[411... 

P R E CONTENTS Preface. Stable-Isotope Assisted Protein NMR Spectroscopy in Solution, Brian J. Stockman and John L. Mar-kley. 31P and 1H Two-Dimensional NMR and NOESY-Dis-tance Restrained Molecular Dynamics Methodologies for Defining Sequence-Specific Variations in Duplex Oligonucleotides, David G. Gorenstein, Robert P. Meadows, James T. Metz, Edward Nikonowcz and Carol Beth Post. NMR Study of B- and Z-DNA Hairpins of d[(CG) 3T4(CG)3] in Solution, Sa-toshi Ikuta and Yu-Sen Wang. Molecular Dynamics Simulations of Carbohydrate Molecules, J.W. Brady. Diversity in the Structure of Hemes, Russell Timkovich and Laureano L. Bon-doc. Index. Volume 2,1991, 180 pp. 112.50/E72.50 ISBN 1-55938-396-8... 

Another conformation different from T-taxol was proposed based on molecular dynamics simulations and computational docking restrained by the two REDOR distances [85], The main difference between this conformer (named REDOR-taxol or PTX-NY) and T-taxol is the conformation of the C13 side chain, that places the 2 -OH in a different orientation. However, subsequent studies demonstrated that PTX-NY is not consistent with the EC density [86, 87],... 

Wang, J., Deng, Y., and Roux, B. (2006) Absolute binding free energy calculations using molecular dynamics simulations with restraining potentials. Biophys. J. 91, 2798-2814. 

Montelione [18, 19] programs alignment random subset is used as input to CONGEN simulated annealing/ restrained molecular dynamics simulations... 

S. W. Homans and M. Forster, Glycobiology, 2, 143 (1992). Application of Restrained Minimization, Simulated Annealing and Molecular Dynamics Simulations for the Conformational Analysis of Oligosaccharides. 

Figure 7 Three-dimensional structure of DNA hairpin d(GCGAAGC) determined using NMR data obtained on a C- and N-labeled molecule. NOE, dihedral, and RDC restrains were applied to refine the structure using molecular dynamics simulations using AMBER 7.0 software package.

---