Methods: We have proposed a simple, biophysically reasonable electron-conformational theory for the ryanodine receptor channel (RyR) to be a main element governing the calcium dynamics in a cardiac cell [1,2], starting with the well-known model theory of the photo-induced structural phase transitions [3]. The main feature of our model is that, in addition to a fast electronic (dichotomic) degree of freedom, the RyR channel is characterized by a slow classical conformational coordinate, Q, that obeys the Langevin dynamics. Two minima of a conformational potential (CP) are related with a closed and open RyR state, respectively. We took into account the calcium induced direct electronic Franck-Condon transitions between the CP branches and different relaxation mechanisms.
Results: We have performed a series of computer simulations of a single RyR stochastic gating under steady-state conditions and made a Hurst analysis of the channel’s conformational coordinate Q(t). Dynamics of our system appears to be strongly correlated (H ≈ 1.0) for relatively short times compared with the characteristic times of conformational relaxation to the metastable minimum of CP, and weakly correlated (H ≈ 0.5) for larger time intervals.