TY - JOUR

T1 - Latent dynamics of a protein molecule observed in dihedral angle space

AU - Omori, Satoshi

AU - Fuchigami, Sotaro

AU - Ikeguchi, Mitsunori

AU - Kidera, Akinori

PY - 2010

Y1 - 2010

N2 - Dihedral angles are alternative set of variables to Cartesian coordinates for representing protein dynamics. The two sets of variables exhibit extremely different behavior. Motions in dihedral angle space are characterized by latent dynamics, in which motion induced in each dihedral angle is always compensated for by motions of many other dihedral angles, in order to maintain a rigid globular shape. Using molecular dynamics simulations, we propose a molecular mechanism for the latent dynamics in dihedral angle space. It was found that, due to the unique structure of dihedral principal components originating in the globular shape of the protein, the dihedral principal components with large (small) amplitudes are highly correlated with the eigenvectors of the metric matrix with small (large) eigenvalues. Such an anticorrelation in the eigenmode structures minimizes the mean square displacement of Cartesian coordinates upon rotation of dihedral angles. In contrast, a short peptide, deca-alanine in this study, does not show such behavior of the latent dynamics in the dihedral principal components, but shows similar behaviors to those of the Cartesian principal components, due to the absence of constraints to maintain a rigid globular shape.

AB - Dihedral angles are alternative set of variables to Cartesian coordinates for representing protein dynamics. The two sets of variables exhibit extremely different behavior. Motions in dihedral angle space are characterized by latent dynamics, in which motion induced in each dihedral angle is always compensated for by motions of many other dihedral angles, in order to maintain a rigid globular shape. Using molecular dynamics simulations, we propose a molecular mechanism for the latent dynamics in dihedral angle space. It was found that, due to the unique structure of dihedral principal components originating in the globular shape of the protein, the dihedral principal components with large (small) amplitudes are highly correlated with the eigenvectors of the metric matrix with small (large) eigenvalues. Such an anticorrelation in the eigenmode structures minimizes the mean square displacement of Cartesian coordinates upon rotation of dihedral angles. In contrast, a short peptide, deca-alanine in this study, does not show such behavior of the latent dynamics in the dihedral principal components, but shows similar behaviors to those of the Cartesian principal components, due to the absence of constraints to maintain a rigid globular shape.

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U2 - 10.1063/1.3360144

DO - 10.1063/1.3360144

M3 - Article

C2 - 20331318

AN - SCOPUS:77949707321

VL - 132

JO - Journal of Chemical Physics

JF - Journal of Chemical Physics

SN - 0021-9606

IS - 11

M1 - 115103

ER -