Infuence of Phosphoenolpyruvate on the Dynamic Behavior of Phosphofructokinase of Escherichia coli

DÍAZ RICCI, JUAN C.

JOURNAL OF THEORETICAL BIOLOGY

ACADEMIC PRESS LTD-ELSEVIER SCIENCE LTD

Lugar: Amsterdam; Año: 1996 vol. 178 p. 145 - 150

0022-5193

Theeffect of phosphoenolpyruvate (PEP) and the substrate input rate (s1) on the dynamic behaviourof the phosphofructokinase (EC 1.6.0.00) (PFK) of Escherichia coli is analysed[ The mathematical model is basedon a well defined one and all kinetic parameters used in this analysiscorrespond specifically to the PFK of E. coli. Results agree with previous reports onlywhen the concentration of PEP is very low (< 10 µM) but change at higher concentrations. Theanalysis of the local stability of PFK reveals the existence of nodes\ spiralsof limit cycles whose dynamic maps depended on the concentration of PEP and thesubstrate input rate. Phosphofructokinase shows higher sensitivity at concentrationsof PEP close to those expected in E. coli (0.1-0.5 mM)The e}ect of PEP on the stability of PFKis complex and depends on the range of PEP concentration and s1. For a given value ofPEP (e.g. 1 mM),PFK can change or even reverse the stability pattern when s1 changes within aparticular range of values of this variable.