Facile assay of enzymes unique to the Calvin cycle in intact cells, with special reference to ribulose 1,5-bisphosphate carboxylase
✍ Scribed by F.Robert Tabita; Pia Caruso; William Whitman
- Publisher
- Elsevier Science
- Year
- 1978
- Tongue
- English
- Weight
- 578 KB
- Volume
- 84
- Category
- Article
- ISSN
- 0003-2697
No coin nor oath required. For personal study only.
✦ Synopsis
A procedure for the facile measurement, in intact cells, of two enzymes unique to the Calvin cycle, ribulose l$bisphosphate carboxylase and phosphoribulokinase, is described. The procedure involved a simple toluene treatment to render phototrophic cells permeable to the necessary substrates, effecters, and cofactors. Whole-cell ribulose 1,5-bisphosphate carboxylase activity quantitatively approximates the activity obtained in cell-free extracts. In addition, the activity measured with toluene-treated whole cells results in a stoichiometric carboxylation of ribulose 15bisphosphate to phosphoglyceric acid. The assay procedures described are most convenient for determining enzyme levels as a function of growth. Moreover, such an assay should open the way to further studies on the regulation of CO, assimilation by direct measurement of the enzymes concerned within the cell.