02023nam a2200289Ia 4500 MX-MdCICY 20260521091450.0 CICY B-15336 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), p.1396-1404, 1985 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 70 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. RIBULOSE BISPHOSPHATE CARBOXYLASE ACTIVATION INORGANIC ORTHOPHOSPHATE CO2 CO-OPERATIVITY Parry, M.A.J. Godfrey Schmidt, C.N. Cornelius, M.J. Keys, A.J. Millard, B.N. Gutteridge, S. https://drive.google.com/file/d/1i_HuWPZYLc2SPAu0tU6YRNj9Bn3jKZav/view?usp=drivesdk Para ver el documento ingresa a Google con tu cuenta: @cicy.edu.mx Loc REF1 250602s9999 xx |||||s2 |||| ||und|d 25456 25456 0 0 Loc 0 0 F1 CICY CICY RE 2025-06-25 0 B-15336 2025-06-25 16:01:31 2025-06-25 REF1