Miriam van Santen writes:
>I'm working on a computer simulation model of the TCA cycle. I'm trying
>to find out if there is anything known about the flux distribution from
>isocitrate to either succinate and glyoxylate or a-ketoglutarate. The
>concentration of malate, succinate and p-enol-pyruvate have a negative
>feedback on the conversion of isocitrate into succinate and glyoxylate.
>Is there a mathematical description for these inhibitions known?
>
Apart from the simulations and data that Pedro Mendes has referred you to,
kinetics of the allosteric inhibition of isocitrate lyase are referred to in
Ashworth & Kornberg, Biochim. Biophys. acta, 73, 519-522, 1963. The
isocitrate dehydrogenase in E. coli is subject to inactivation by protein
phosphorylation; see Walsh & Koshland, J. Biol. Chem. 260, 8430-8437 (1985)
for details. Walsh & Koshland varied the split between TCA cycle and
glyoxalate cycle by varying the expression of citrate synthase in E. coli,
PNAS 82, 3577, (1985).
=========================================================
David Fell,
School of Biological & Molecular Sciences,
Oxford Brookes University,
Oxford OX3 0BP, Tel. +44 (0)1865 483247
UK FAX +44 (0)1865 484017
daf at bms.brookes.ac.uk
