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Table 1 Activation kinetics of ADP-Glc PPases from Anabaena , O. tauri , and potato tuber

From: The ancestral activation promiscuity of ADP-glucose pyrophosphorylases from oxygenic photosynthetic organisms

Enzyme v0(U mg-1) Activator A0.5(mM) Activation fold Net activation fold Specificity constant (mM-1)
Anabaena 0.77 3-PGA 0.075 5.5 4.5 60
   FBP 0.30 1.2 0.2 0.7
   Fru6P 1.6 2.5 1.5 1.0
   Glc6P 0.40 1.4 0.4 1.0
OtaS/OtaL 0.89 3-PGA 0.54 33 32 59
   FBP 1.1 7.0 6.0 5.5
   Fru6P 15 2.7 1.7 0.1
   Glc6P 75 17 16 0.2
StuS/StuL 0.27 3-PGA 0.054 68 67 1241
   FBP 0.84 6.0 5.0 6.0
   Fru6P 1.5 57 56 36
   Glc6P 1.8 29 28 15
OtaS 0.25 3-PGA 1.2 10 9.0 8.0
   FBP 1.1 9.3 8.3 7.6
   Fru6P 1.9 3.9 2.9 1.6
   Glc6P 10 5.5 4.5 0.4
OtaSD148A/OtaL 0.57 3-PGA 0.003 7.0 6.0 2000
   FBP 8.2 5.0 4.0 0.5
   Fru6P 0.74 5.0 4.0 5.4
   Glc6P 65 26 25 0.4
OtaS/OtaLD171A 0.12 3-PGA 0.067 5.1 4.1 61
   FBP 1.5 5.9 4.9 3.3
   Fru6P 2.9 5.0 4.0 1.4
   Glc6P 3.1 3.4 2.4 0.8
  1. Activity of the purified enzymes was assayed in the ADP-Glc synthesis direction. Kinetic parameters were calculated as described under “Methods”. For each enzyme and each activator the Vmax can be calculated as v0 times the Activation Fold. StuS and StuL are the S and L subunits of potato tuber, and OtaS and OtaL the S and L subunits of O. tauri, respectively.