Abstract
Calorimetric experiments were performed on yeast extracts in which glycolytic oscillations were occurring. High metabolic fluxes coincided with low amplitudes and with high frequencies in a temperature range from 283 to 303 K, yielding an activation energy ofEa=76.8 kJ mol−1 and a mean Q10 value of 2.5±0.4. The calorimetrically determined reaction enthalpy ΔfH0, of the glycolytic catabolism of glucose revealed two distinct groups of extract preparations, with no intermediate values. The values were −107.5±28.7 kJ mol−1 and −30.8±5.7 kJmol−1, respectively, while −100.0 kJ mol−1 was predicted from theoretical calculations. Kreuzberg and Betz6 predicted rate limiting effects of GAPDH in oscillating extracts. However, when possible effects of GAPDH on frequency, number of oscillations or total heat production were examined, no influence of increasing or reducing the initial GAPDH concentration could be found. The results are discussed with reference to existing models of glycolytic oscillations.
Published Version
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call