2,3-DPG (or 2,3 bisphosphoglycerate as we Europeans say) is an inhibitor of
oxygen binding found in the red cells of many (but not all, e.g. ruminants)
mammals. Birds don't use it, but have inositol hexaphosphate instead. 2,3
BPG was discovered in the '70s, rather late considering there had already
been nearly a century of haemoglobin research by then, and its concentration
is around 5mM, so it compares with ATP as a major organic phosphate in the
red cell. It is the cofactor of phosphoglycerate mutase that is present in
all glycolysing cells, but usually at trace levels. Mammalian red cells
make much more of it. Its synthesis is pH-dependent and it can therefore
respond to the oxygenation state of the red cell (because of the Bohr
shift), but this takes some time because of the very low rate of glycolysis
in red cells.
David Fell
=========================================================
David Fell,
School of Biological & Molecular Sciences,
Oxford Brookes University,
Oxford OX3 0BP, Tel. +44 (0)1865 483247
UK FAX +44 (0)1865 484017
daf at bms.brookes.ac.uk
