Review lecture 2 Michaelis-Menten kinetics E+S、仝ES>E+P k d[s=,[EIS+KES dt d[日 -k1日[S+(k1+k2)ES dt des dt K,EIIS-(k_1+k2IES dP KIES dt
Review Lecture 2 Michaelis-Menten kinetics E + S ES E + P k 1 k-1 k 2 d [S ] dt = − k 1 [ E][S ] + k − 1 [ES] d [ E] dt = − k 1 [ E][ S] + ( k − 1 + k 2)[ES] d [ES] dt = k 1 [ E][ S] − ( k − 1 + k 2)[ES] dP dt = k 2 [ES] ≡ v
E。=[E+[ES dIs k1毛[S+(kS+k1E§ dt dEs dt K,E[S-(K,S+k_1+k2[ES 工ni七 ial condi tions: [S] t=0 [E] LESI [P] t=0
Eo = [E] +[ES] d[S] dt = −k 1Eo [S] + (k 1[S] +k −1 )[ES] d[ES] dt = k1Eo[S] − (k1[S] + k −1 + k 2)[ES] Initial conditions: [S]t=0 = So [E]t=0 = Eo [ES]t=0 = 0 [P]t=0 = 0
1.0H transient quasi steady state i substrate depletion 0.8 0.6 0.4 0.2 ES 0.0 0.1 10 100 time(s)
0÷maxo K +s m Good approximation if s >>e in this case So w [s] at the start of quasi-steady state
m o max o 0 K S v S v + = Good approximation if So >> Eo in this case S0 ~ [S] at the start of quasi-steady state
Review lecture 2 Equilibrium binding and cooperativity S+P,<>P, j-1 Adair′ s Equation: K1[S]+2K1K2s]+31K2K2{s]+…+nK1K2…K[S 1+K,[s]+K,K[s]+..+K,KK[s P macroscopic association constant K [P. ][s] for transitions between state j-1 and j
Review Lecture 2 Equilibrium binding and cooperativity jP j 1 S P ↔ − + n n n n ...K [S] 2K1 ... K 2 [S] 2K1 [S] K 1 1 K ...K [S] 2K1 ... nK 3 [S] 3K2K1 3K 2 [S] 2K1 [S] 2K 1K r + + + + + + + + = Adair’s Equation: ][S] j 1 [P ]j [P jK − = macroscopic association constant for transitions between state j-1 and j