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Table 3 Control coefficients in the fasted and fed state. 0.00 means –0.005 < value <0.005

From: The relative importance of kinetic mechanisms and variable enzyme abundances for the regulation of hepatic glucose metabolism – insights from mathematical modeling

Enzyme Fasted state Fed state Enzyme Fasted state Fed state
4 mM glucose a 10 mM glucose b 4 mM glucose b 10 mM glucose a 4 mM glucose a 10 mM glucose b 4 mM glucose b 10 mM glucose a
ALD 0.00 0.00 0.00 0.00 MDHmito 0.00 0.00 0.00 0.00
EN 0.00 0.00 0.00 0.00 NDKUTP 0.00 0.00 0.00 0.00
FBP1 0.01 –0.03 0.04 0.00 NDKGTP 0.00 0.00 0.00 0.00
FBP2 0.00 –2.01 0.12 –0.18 NDKmito(GTP) 0.00 0.00 0.00 0.00
GAPDH 0.00 0.00 0.00 0.00 PC 0.66 –0.25 0.60 –0.01
GK 0.00 2.87 –0.05 0.56 PEPCK 0.00 0.00 0.00 0.00
GlcT 0.00 0.27 0.04 0.54 PEPCKmito 0.00 0.00 0.00 0.00
GlcTER 0.00 0.00 0.00 0.00 PEPT 0.00 0.00 0.00 0.00
GP –0.04 0.11 –0.08 0.00 PFK1 0.00 0.22 0.00 0.01
G6P 0.06 –2.34 0.30 –0.12 PFK2 0.00 2.01 –0.12 0.18
GPI 0.00 0.00 0.00 0.00 PGK 0.00 0.00 0.00 0.00
G6PTER 0.00 0.00 0.00 0.00 PGM 0.00 0.00 0.00 0.00
GS 0.04 –0.15 0.06 0.00 PK –0.01 0.28 –0.06 0.01
LacT 0.28 0.01 0.14 0.00 PyrT 0.00 0.00 0.00 0.00
LDH 0.00 0.00 0.00 0.00 PyrMalT 0.00 0.00 0.00 0.00
MDH 0.00 0.00 0.00 0.00 TPI 0.00 0.00 0.00 0.00
  1. For the numerical calculation of the control coefficients the amounts of the catalyzing enzymes were varied by 5 % (0.5 % yielded similar results). The sum of all control coefficients is equal to unity (summation theorem) within the limit of numerical accuracy
  2. a In bold font are the control coefficients for the physiological states (i.e. fasted protein profile and 4 mM plasma glucose and low glycogen store and fed protein profile and 10 mM blood glucose and high glycogen store)
  3. b In normal font are the control coefficients for the two states with the respective other protein profile. The reference flux values are –64 μmol/g/h for fasted hepatocytes and 81 μmol/g/h for fed hepatocytes
  4. ALD Aldolase, EN Enolase, ER Endoplasmic reticulum, FBP1 Fructose-1,6-bisphosphatase, FBP2 Fructose-2,6-bisphosphatase, GAPDH Glyceraldehyde 3-phosphate dehydrogenase, GK Glucokinase, GlcT Glucose transporter, G6P Glucose-6-phosphate phosphatase, GPI Glucose-6-phosphate isomerase, G6PT Glucose-6-phosphate transporter, GTP Guanosine triphosphate, GS Glycogen synthetase, LacT Lactate transporter, LDH Lactate dehydrogenase, MDH Malate dehydrogenase, mito Mitochondrion, NDK Nucleoside-diphosphate kinase, PyrMalT Pyruvate/malate antiporter, PC Pyruvate carboxylase, PEPCK Phosphoenolpyruvate carboxykinase, PEPT Phosphoenolpyruvate transporter, PFK1/2 Phosphofructokinase-1/2, PGK Phosphoglycerate kinase, PGM Phosphoglycerate mutase, PK Pyruvate kinase, PyrT Pyruvate transporter, TPI Triose-phosphate isomerase, UTP Uridine triphosphate