  The importance of torsion vibration in the transmission of life information
is indicated. The localization of quantum torsion state is proved. Following
these analyses a formalism on the quantum theory of conformation-electron
system is proposed. The conformational-electronic transition is calculated by
non-adiabatic operator method. The protein folding is viewed from
conformational quantum transition and the folding rate is calculated. The
time-scale of microsecond to millisecond for the fundamental folding event
(nucleation, collapse, etc) is deduced. The dependence of transition rate W on
N inertial moments is given. It indicates how W increases with the number N of
torsion angles and decreases with the inertial moment I of atomic group in
cooperative transition. The temperature dependence is also deduced which is
different from chemical reaction in high-temperature region. It is demonstrated
that the conformational dynamics gives deep insights into the folding mechanism
and provides a useful tool for analyzing and explaining experimental facts on
the rate of protein folding.
