Ing-Nang Wang writes:
> I am reading something about pentose phosphate cycle. However, I don't
> know the most current consensus on this pathway. It seems to me that the
> early history in the study of this pathway is about the direction of flux
> of oxidative and non-oxidative branches. In light of metabolic control
> theory and all that, what do people know about this pathway? Have a lot of
> progress been made since the 60s?
A most interesting recent analysis of the pentose phosphate cycle in
the context of evolution of metabolism has been made by Enrique
Melendez-Hevia, basing his views on his innovative `Game of the pentose
phosphate cycle'. He shows that the pathway found today in contemporary
organisms is the simplest solution to the combinatorial problem of
transforming 6 C5-sugars to 5 C6-sugars within certain chemical constraints.
These findings are then generalised to new theorems of metabolic evolution.
The reference is
Melendez-Hevia, Waddell & Montero (1994) Optimization of Metabolism:
The evolution of metabolic pathways towards simplicity through the game of
the pentose phosphate cycle.
Journal of Theoretical Biology 166, 201-220.
This paper also refers to other papers more concerned with the state-of-art
biochemistry of the pentose phosphate cycle.
Jannie Hofmeyr InterNet e-mail: jhsh at maties.sun.ac.za
Dept. of Biochemistry Telephone: +27 21 8083039
University of Stellenbosch Fax: +27 21 8083022