David LaPorte Biochem
david-l at htlv.med.umn.edu
Fri Mar 11 14:38:51 EST 1994
jmello1 at umbc.edu (mellott james ( bs bioc)) writes:
> In my biochemistry class , we're talking about glycolysis , TCA , etc.,
>and one of the topics is the regulation of glycogen through a cAMP pathway . It
>is my understanding that a high concentration of cAMP is needed for the
>continuous activation of Protein kinase , and to inactivate the kinase , the
>concentration of cAMP is lowered through the activity of a phosphodiesterase .
>I recall hearing that caffeine stabilizes the concentration of cAMP in such a
>pathway , and I was wondering , since caffeine and adenine have similar
>structures , if caffeine acts as a competitive inhibitor with cAMP for the
Caffeine, theophiline and related compounds are, indeed, inhibitors of
phosphodiesterase. As I recall, however, that is not their biological
site of action. The concentrations required to produce a physiological
effect are too low to inhibit PDE.
U. of Minn.
david-l at microbe.med.umn.edu
More information about the Proteins