Premium
Equilibration of metabolic CO 2 with preformed CO 2 and bicarbonate
Author(s) -
Hems Reginald,
Saez Guillermo T.
Publication year - 1983
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/0014-5793(83)80659-0
Subject(s) - bicarbonate , chemistry , pyruvate dehydrogenase complex , biochemistry , urea , carbon fixation , oxoglutarate dehydrogenase complex , cytoplasm , enzyme , pyruvate dehydrogenase phosphatase , organic chemistry , photosynthesis
Entry of metabolic 14 CO 2 into urea is shown to occur more readily than it equilibrates with the general pool of cellular plus extracellular bicarbonate plus CO 2 . Since the sites of CO 2 production (pyruvate dehydrogenase and oxoglutarate dehydrogenase) and of fixation (carbamoylphosphate synthetase) are intramitochondrial, it is likely that the fixation of CO 2 is also more rapid than its equilibration with the cytoplasmic pool of bicarbonate plus CO 2 . This observation may point to a more general problem concerning the interpretation of isotope data, when compartmentation or proximity of sites of production and utilisation of metabolites may result in the isotope following a preferred pathway.