Elucidation of molecular kinetic schemes from macroscopic traces using system identification
Fig 7
Molecular kinetic scheme and effects of nifedipine on L-type calcium channel traces.
(A) Representative L-type calcium ion-channel current (output) elicited by voltage steps from -90 to 0 mV (input), first in the absence of nifedipine, and after addition of nifedipine at 100 nM and 1 μM concentrations. (B) Molecular kinetic scheme obtained by applying SYSMOLE to the traces and expected effects of nifedipine on transition rates. (C) Fractional occupancies as a function of time of the closed-channel (black), open-channel (red), and inactivated-channel (blue) states resulting from simulating the molecular kinetic scheme. Simulations were generated with the mean value of the kinetic parameters (N = 3–6 traces per treatment). Kinetic parameter values can be found on Table 1.