1 TCa kon Ca T koff TCa 1 P0 N1 P1 k1_ P1 g N1 k1 N1 k1 N0 g P1 k1_ P0 f P0 k1 N1 f P0 k1_ P1 g P1 k1_ TCa K_1_2 N 1 1 K_Ca 1.5 SL_norm 1 7 3 SL_norm SL 1.7 2.3 1.7 alpha P1 N1 Fmax f f g