It is almost 20 years since I thought seriously about this, so it is
quite possible that more recent information than I have is available,
but maybe not, so it may still be worthwhile giving some references to
some papers from the 1970s, as well as one earlier one:
D. E. Atkinson (1969) Current Topics Cell. Reg. 1, 29-43
A. R. Fersht (1974) Proc. Roy. Soc. ser. B 187, 397-407
A. Cornish-Bowden (1976) J. Mol. Biol. 101, 1-9
In the last of these three I tried to review such evidence as existed
about the actual concentrations of substrates in vivo, and came to the
conclusion that for the glycolytic enzymes (apart from aldolase) they
were indeed reasonably close to Michaelis constant values, but for
other classes of enzymes such as the catabolic enzymes primarily
considered by Fersht they were more likely to be much higher. The
reference to Lowry & Passonneau (1964) J. Biol. Chem. 239, 31-42 in my
paper suggests that they were just concerned with aldolase, but my
recollection (I have looked at the paper for a long time) is that they
considered all the enzymes of glycolysis, not just aldolase.
I did a somewhat more detailed study afterwards in reply to a paper
that Fersht wrote in response to mine, but as his reply was never
published (as far as I know), my reply to it was never submitted for
publication. I probably have the MS somewhere, but I fear it is
unlikely that I can find it.
It is probably worth adding that all of these papers (as well as
Cleland's of 1967 that you refer to) were written independently of any
knowledge of metabolic control analysis, and contains points that now
seem rather naive.
Athel Cornish-Bowden
athel at ibsm.cnrs-mrs.fr
