Many of us active in this field have felt frustrated that the standard
textbooks that biochemistry students around the world read continue to
repeat the same old nonsense, such as the idea that phosphofructokinase
controls the glycolytic flux (or is it pyruvate kinase? or hexokinase? or
all three, as Stryer seems to think?).
Part of the problem is that if one points out that this makes little sense
one is likely to be thought a member of a far-out group of theoreticians
out of touch with the real world. So I have long thought it essential to
publicize as widely as possible the purely experimental observation that
increasing the activity of phosphofructokinase in fermenting yeast 3.5-fold
has *no effect* at all on the flux to ethanol (Heinisch, 1986). After
nearly 15 years it doesn't seem to have occurred to most textbook authors
that this is a simple experimental fact that their theoretical statements
need to be able to cope with.
As this is just one of several errors (mostly not specifically related to
metabolic regulation) that I have noticed over the years to be very
frequent in textbooks, I was amusing myself during April trying to compile
some statistics, and I have assembled the results into a series of web
pages, of which the phosphofructokinase page is at
http://ir2lcb.cnrs-mrs.fr/~athel/rls.htm (with links to the others).
I should be interested to know the opinions of subscribers to this group
about whether the points I make about rate-limiting steps on the page cited
are valid, and, of course, if anyone has views on the others I'll be glad
to hear about them also.
athel
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