Lancaster EPrints

Stimulation of ribulose bisphosphate carboxylase activity by inorganic orthophosphate without an increase in bound activating CO2:co-operativity between the subunits of the enzyme

Parry, Martin A. J. and Schmidt, C. N. Godfrey and Cornelius, Martin J. and Keys, Alfred J. and Millard, Barbara N. (1985) Stimulation of ribulose bisphosphate carboxylase activity by inorganic orthophosphate without an increase in bound activating CO2:co-operativity between the subunits of the enzyme. Journal of Experimental Botany, 36 (9). pp. 1396-1404. ISSN 0022-0957

Full text not available from this repository.

Abstract

Ribulose bisphosphate carboxylase/oxygenase (E.C. 4.1.1.39) from wheat (Triticum aestivum L.), already activated by reaction with CO2 and Mg2+, was increased in activity on addition of inorganic orthophosphate. This further activation took place without a significant increase in the amount of bound activating CO2 and the effect was relatively greater with smaller amounts of bound CO2. With less than 2·0 mol of CO2 bound per mol holoenzyme, phosphate increased activity about five-fold whilst with 7·0 mol of bound activating CO2 per mol holoenzyme, phosphate increased activity by a factor of only 1 ·8. This decrease in the effect of orthophosphate with increase in bound activating CO2 suggests negative co-operativity between activated sites. The stimulation of activity by inorganic orthophosphate must be a process distinct from activation by CO2; it was observed with both the slow and the rapidly activating forms of ribulose bisphosphate carboxylase/oxygenase from wheat.

Item Type: Article
Journal or Publication Title: Journal of Experimental Botany
Uncontrolled Keywords: Activation ; Co-operativity ; Inorganic orthophosphate CO2 ; Ribulose bisphosphate carboxylase
Subjects:
Departments: Faculty of Science and Technology > Lancaster Environment Centre
ID Code: 76071
Deposited By: ep_importer_pure
Deposited On: 21 Oct 2015 06:04
Refereed?: Yes
Published?: Published
Last Modified: 19 Nov 2017 12:54
Identification Number:
URI: http://eprints.lancs.ac.uk/id/eprint/76071

Actions (login required)

View Item