Derivation of extremely slow dynamics of protein motion based on entropy invariance

It is a mysterious fact that protein systems often show an extremely slow dynamics of their molecular motions with time scales much longer than nanosecond order, although their characteristic frequencies obtained by the normal mode analysis fall in much shorter temporal regions. This Letter provides a heuristic account for why and how such extremely slow modes of protein motions naturally emerge from fast molecular modes on the basis of an idea of entropy invariance in the principal component analysis.