Hi, I'm more of a Fourier coefficient kind of guy, but I thought that a ΔG of zero simply corresponded to an equilibrium constant of one. You can certainly have reversible reactions with other equilibrium constants. In fact I think "irreversible" reactions are simply ones where the equilibrium constant is so far to one side that, in practice, the reaction always goes all the way to product.
As Randy pointed out the enzyme cannot change the ΔG (or the equilibrium constant). You could drive a reaction out of equilibrium by coupling it to some other reaction which itself is way out of equilibrium (such as ATP hydrolysis in the cell) but I don't think that's a simple mutation of your enzyme. ;-) Dale Tronrud On 05/18/10 00:31, Vinson LIANG wrote: > Dear all, > > Sorry for this silly biochemistory question. Thing is that I have a > reversible epimerase and I want to mutate it into an inreversible one. > However, I have been told that the ΔG of a reversible reaction is zero. > Which direction the reaction goes depends only on the concentration of > the substrate. So the conclusion is, > > A: I can mutate the epimerase into an inreversible one. But it has no > influence on the reaction direction, and hence it has little mean. > > B: There is no way to change a reversible epimerase into an inversible one. > > Could somebody please give me some comment on the two conclution? > > Thank you all for your time. > > Best, > > Vinson > > >
