Table 3 Effects of lactate on the kinetic parameters for ATP and F6P on skeletal muscle PFK

The parameters for ATP were calculated fitting eqn (3) to the experimental data presented in Figure 2(A) and for F6P were calculated fitting the parameters of eqn (4) to the experimental data presented in Figure 2(B). *P<0.05 compared with the control in the absence of lactate. †P<0.05 compared with the control in the absence of lactate and to the presence of 5 mM lactate.

Kinetic parameters for ATP
Stimulatory componentInhibitory componentKinetic parameters for F6P
LactateK0.5 (mM)n1I0.5 (mM)n2Vmax (m-units/μg)K0.5 (mM)n
None0.57±0.052.1±0.42.27±0.333.8±0.53.2±0.20.19±0.032.0±0.1
5 mM0.98±0.08*0.16±0.022.0±0.2
10 mM0.93±0.07*1.2±0.2*3.79±0.32*8.0±0.9*0.21±0.02†0.41±0.03†2.0±0.7