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. 2013 Aug 16;8(8):e71060. doi: 10.1371/journal.pone.0071060

Table 1. Enzymatic reactions included in the model a.

Enzyme/Process Abbreviation Substrates d Products e Effectors f
Hexokinase HK GLC + MgATP → G6P + MgADP 2,3-BPG, GDP, GSH, pH
Phosphoglucoisomerase PGI G6P ↔ F6P
Phosphofructokinase PFK F6P + MgATP → F1,6-BP + MgADP fATP, Mg, 2,3-BPG, fAMP, Pi, GDP, pH
Aldolase ALD F1,6-BP ↔ DHAP + GA3P 2,3-BPG, Mg2,3-BPG
Triose phosphate isomerase TPI DHAP ↔ GA3P
Glyceraldehyde phosphate dehydrogenase GAPDH GA3P + Pi + NAD ↔ 1,3-BPG + NADH pH
2,3-Bisphosphoglycerate shunt BPGSP 1,3-BPG → 2,3-BPG + 3PG + Pi pH
Phosphoglycerate kinase PGK 1,3-BPG + MgADP ↔ 3PG + Pi
Phosphoglyceromutase PGM 3PG ↔ 2PG
Enolase EN 2PG ↔ PEP Mg
Pyruvate kinase PK PEP + MgADP ↔ PYR + MgATP ATP, F1,6-BP, GDP, pH
Lactate dehydrogenase LDH PYR + NADH → LAC + NAD pH
Lactate dehydrogenase (NADPH) LDHP PYR + NADPH → LAC + NADP
Glucose 6-phosphate dehydrogenase G6PDH G6P + NADP → GL6P + NAPDH MgATP, 2,3-BPG
6-Phosphogluconolactonase 6PGLase GL6P → GO6P
6-Phosphogluconate dehydrogenase 6PGODH GO6P + NADP ↔ RU5P + NADPH + CO2
Transaldolase TA S7P + GA3P → E4P + F6P
Transketolase1 TK1 X5P + R5P → GA3P + S7P
Transketolase2 TK2 X5P + E4P → GA3P + F6P
Ribose 5-phosphate isomerase R5PI RU5P → R5P
Xylulose 5-phosphate isomerase X5PI RU5P → X5P
Gamma-glutamyl cysteine synthetase L_GCS MgATP + glutamate + cysteine ↔ MgATP + L_GC + Pi GSH
Glutathione synthetase GSH_S L_GC + glycine + MgATP ↔ GSH + MgATP + Pi
Glutathione reductase GSSGR GSSG + NADPH → GSH + MgADP + Pi
Adenosine kinase AK ADO + MgATP → MgADP + fAMP
Hypoxanthine-guanine phosphoryl transferase HGPRT PRPP + HXi → IMP + 2Pi
Adenosine deaminaseb ADA ADO + MgATP ↔ INO
Adenine phosphoribosyl transferaseb ADPRT ADE + PRPP → fAMP + 2Pi
Adenosine monophosphate deaminaseb AMPDA fAMP → IMP
Adenosine monophosphate phosphohydrolaseb AMPase fAMP ↔ ADO + Pi
Inosine monophosphataseb IMPase IMP ↔ INO + Pi
Purine nucleoside phophorylaseb PNPase INO + Pi → HXi + R1P
Phosphoribomutaseb PRM R1P → R5P
Phosphoribosyl pyrophosphate synthetaseb PRPPsyn R5P + MgATP → PRPP + fAMP + Mg
Purine nucleoside phophorylase PNPase2 GUO + Pi → GUA + R1P
Adenylate kinase APK ADP + MgADP → AMP + MgATP
Adenosine triphosphate phosphohydorolase ATPase MgATP → MgADP + Pi
Glutathione turnover OX 2GSH → GSSG
Non-glycolytic NADH consumption process OXNADH NADH → NAD
Adenine transport process ADEtr ADE → ADEe
Adenosine transport process ADOtr ADO → ADOe
Hypoxanthine transport process HXtr HXi → HXe ADEe
Inosine transport process INOtr INO → INOe
Lactate transport process LACtr LAC → LACe
Pyruvate transport process PYRtr PYR → PYRe
Inorganic phosphate transport process Pitr Pi → Pie
GSSG transport process GSSG transport GSSG + MgATP → GSSGe + MgADP + Pi
Leak of potassium K_Leak Ke ↔ Ki
Leak of sodium Na_Leak Nae → Nai
Sodium/potassium pumpc Na+/K+ pump 3Nai + 2Ke + MgATP → 3Nae + 2Ki + MgADP + Pi
a

From [8].

b,c

The enzyme activities in the model were divided into 3 groups: activities of 8 enzymes in purine salvage pathway (b), the activity of the Na+/K+ pump (c), and the remaining other enzymatic or binding activities [9].

d,e,f

Abbreviations used in this table are as follows: GLC, glucose; G6P, glucose 6-phosphate; F6P, fructose 6-phosphate; F1,6-BP, fructose 1,6-bisphosphate; DHAP, dihydroxyacetone phosphate; GA3P, glyceraldehyde 3-phosphate; 1,3-BPG, 1,3-bisphosphoglycerate; 2,3-BPG, 2,3-bisphosphoglycerate, 3PG, 3-phosphoglycerate; 2PG, 2-phosphoglycerate; PEP, phosphoenolpyruvate; PYR, pyruvate; LAC, lactate; GL6P, gluconolactone 6-phosphate; GO6P, gluconate 6-phosphate; RU5P, ribulose 5-phosphate; X5P, xylulose 5-phosphate; E4P, erythrose 4-phosphate; S7P, sedoheptulose 7-phosphate; R5P, ribose 5-phosphate; PRPP, 5-phosphoribosyl 1-phosphate; ADE, adenine; IMP, inosine monophosphate; R1P, ribose 1-phosphate; INO, inosine; ADO, adenosine; HX, hypoxanthine; AMP, adenosine monophosphate; ADP, adenosine diphosphate; ATP, adenosine triphosphate; NADP, nicotinamide adenine dinucleotide phosphate; NADPH, nicotinamide adenine dinucleotide phosphate (reduced); NAD, nicotinamide adenine dinucleotide; NADH, nicotinamide adenine dinucleotide (reduced); Ki, potassium ion; Nai, Sodium ion; Pi, inorganic phosphate; L_GC, l-glutamyl cysteine; GSH, glutathione (reduced); GSSG, glutathione (oxidized).