Am 06.12.2007, 14:20 Uhr, schrieb Ligong Wang <ligongw2004 from yahoo.com>:
> Can one get a Kd (or Ki) value from an assay that is lower than the
> amount (concentration) of protein/enzyme used therein?
The answer from Radio Eriwan: Yes in principle, but the error increases.
Best results are obtained when both [E] and [S] are within 1 order of
magnitude of Kd. But the law of mass action does apply outside that range
too.
For a good discussion on practical enzyme kinetics see the book by
Bisswanger (Enzyme Kinetics - Theory and Methods), but the next english
edition is about to be published this spring, so do not buy just yet
(those who can read German may of course get the original, which was
publihed some time ago).