Pathways

Pantoprazole is used for the management of gastroesophageal reflux disease (GERD), for gastric protection to prevent recurrence of stomach ulcers or gastric damage from chronic use of NSAIDs, and for the treatment of pathological hypersecretory conditions including Zollinger-Ellison (ZE) Syndrome. It can also be found in quadruple regimens for the treatment of H. pylori infections along with other antibiotics including amoxicillin, clarithromycin, and metronidazole, for example. Pantoprazole is a prodrug administered orally but since it degrades rapidly at low pH, the capsule contains enteric-coated granules. After undergoing absorption in the small intestine, it passes from the blood stream into the parietal cells in the stomach, then enters the stomach lumen. It is a weak base and thus, accumulates on the outside of cell in the acidic environment. Its main target is the H+/K+ ATPase in the parietal cells in the stomach. In parietal cells, carbonic anhydrase converts water and carbon dioxide to hydrogen bicarbonate ions and H+. The bicarbonate ions go into the blood via the chloride anion exchanger on the basolateral membrane which exchanges the hydrogen bicarbonate for Cl- ions. There is also the Na+/K+ ATPase which pumps Na+ out of the cell and K+ into the cell. The H+/K+ ATPase is located on the apical membrane and pumps the H+ from the cell into the stomach lumen and K+ from the lumen into the cell. Another transporter, the K+/Cl- symporter transports K+ and Cl- in the stomach lumen. The H+ and Cl- in the stomach lumen forms the HCl acid which, in excess, can cause disorders like ulcers. The acidic environment in the stomach converts the prodrug pantoprazole into its active form, sulfenamide. Sulfenamide then covalently binds to the cysteine residues on the alpha subunit of the H+/K+ ATPase via disulfide bridges. This binding of sulfenamide irreversibly inhibits the H+/K+ ATPase, preventing too much acid secretion in the stomach. Less acid in the stomach is favorable for symptomatic relief of disorders caused by the acid. Side effects of taking pantoprazole may include headache, diarrhea, stomach pain, constipation, nausea, vomiting, flatulence, dizziness.

Pantoprazole is a proton pump inhibitor (PPI) class drug that suppresses the final step in gastric acid production. In this pathway, pantoprazole is oxidized in the stomach to form the active metabolite of pantoprazole. This active metabolite then binds covalently to the potassium-transporting ATPase protein subunits, found at the secretory surface of the gastric parietal cell, preventing any stimulus. Because the drug binds covalently, its effects are dose-dependent and last much longer than similar drugs that bind to the protein non-covalently. This is because additional ATPase enzymes must be created to replace the ones covalently bound by pantoprazole. Pantoprazole is used to manage gastroesophageal reflux disease, to prevent stomach ulcers, and can be used to help treat the effects of a H. pylori infection.

Pantoprazole is a proton pump inhibitor (PPI) class drug that suppresses the final step in gastric acid production. In this pathway, pantoprazole is oxidized in the stomach to form the active metabolite of pantoprazole. This active metabolite then binds covalently to the potassium-transporting ATPase protein subunits, found at the secretory surface of the gastric parietal cell, preventing any stimulus. Because the drug binds covalently, its effects are dose-dependent and last much longer than similar drugs that bind to the protein non-covalently. This is because additional ATPase enzymes must be created to replace the ones covalently bound by pantoprazole. Pantoprazole is used to manage gastroesophageal reflux disease, to prevent stomach ulcers, and can be used to help treat the effects of a H. pylori infection.

The CoA biosynthesis requires compounds from two other pathways: aspartate metabolism and valine biosynthesis. It requires a Beta-Alanine and R-pantoate. The compound (R)-pantoate is generated in two reactions, as shown by the interaction of alpha-ketoisovaleric acid, 5,10 methylene-THF and water through a 3-methyl-2-oxobutanoate hydroxymethyltransferase resulting in a tetrahydrofolic acid and a 2-dehydropantoate. 2-dehydropantoate interacts with hydrogen through a NADPH driven acetohydroxy acid isomeroreductase resulting in the release of NADP and R-pantoate. On the other hand L-aspartic acid interacts with a hydrogen ion and gets decarboxylated through an Aspartate 1- decarboxylase resulting in a carbon dioxide and a Beta-alanine. Beta-alanine and R-pantoate interact with an ATP driven pantothenate synthetase resulting in pyrophosphate, AMP, hydrogen ion and pantothenic acid. Pantothenic acid is phosphorylated through a ATP-driven pantothenate kinase resulting in a ADP, a hydrogen ion and D-4'-Phosphopantothenate. The latter interacts with a CTP and a L-cysteine resulting in a fused 4'phosphopantothenoylcysteine decarboxylase and phosphopantothenoylcysteine synthetase resulting in a hydrogen ion, a pyrophosphate, a CMP and 4-phosphopantothenoylcysteine. The latter compound interacts with a hydrogen ion through a fused 4'-phosphopantothenoylcysteine decarboxylase and phosphopantothenoylcysteine synthetase resulting in the release of carbon dioxide and 4-phosphopantetheine. 4-phosphopantetheine reacts with ATP, hydrogen ion and an phosphopantetheine adenylyltransferase resulting in a release of pyrophosphate, and dephospho-CoA. Dephospho-CoA reacts with an ATP driven dephospho-CoA kinase resulting in a ADP , a hydrogen ion and a Coenzyme A. Dephospho-CoA also reacts with 2-(5''-triphosphoribosyl)-3'-dephosphocoenzyme-A synthase (citG) to form both adenine and 2'-(5-Triphosphoribosyl)-3'-dephospho-CoA. In this pathway, all enzymes are essential for the cell growth. Biosynthetic pathway for producing CoA is same for most organisms (with exception of differences in the functionality of involved enzymes). In plants, every step is catalyzed by monofunctional enzymes instead of biofunctional enzymes.

The CoA biosynthesis requires compounds from two other pathways: aspartate metabolism and valine biosynthesis. It requires a Beta-Alanine and R-pantoate. The compound (R)-pantoate is generated in two reactions, as shown by the interaction of alpha-ketoisovaleric acid, 5,10 methylene-THF and water through a 3-methyl-2-oxobutanoate hydroxymethyltransferase resulting in a tetrahydrofolic acid and a 2-dehydropantoate. 2-dehydropantoate interacts with hydrogen through a NADPH driven acetohydroxy acid isomeroreductase resulting in the release of NADP and R-pantoate. On the other hand L-aspartic acid interacts with a hydrogen ion and gets decarboxylated through an Aspartate 1- decarboxylase resulting in a carbon dioxide and a Beta-alanine. Beta-alanine and R-pantoate interact with an ATP driven pantothenate synthetase resulting in pyrophosphate, AMP, hydrogen ion and pantothenic acid. Pantothenic acid is phosphorylated through a ATP-driven pantothenate kinase resulting in a ADP, a hydrogen ion and D-4'-Phosphopantothenate. The latter interacts with a CTP and a L-cysteine resulting in a fused 4'phosphopantothenoylcysteine decarboxylase and phosphopantothenoylcysteine synthetase resulting in a hydrogen ion, a pyrophosphate, a CMP and 4-phosphopantothenoylcysteine. The latter compound interacts with a hydrogen ion through a fused 4'-phosphopantothenoylcysteine decarboxylase and phosphopantothenoylcysteine synthetase resulting in the release of carbon dioxide and 4-phosphopantetheine. 4-phosphopantetheine reacts with ATP, hydrogen ion and an phosphopantetheine adenylyltransferase resulting in a release of pyrophosphate, and dephospho-CoA. Dephospho-CoA reacts with an ATP driven dephospho-CoA kinase resulting in a ADP , a hydrogen ion and a Coenzyme A. Dephospho-CoA also reacts with 2-(5''-triphosphoribosyl)-3'-dephosphocoenzyme-A synthase (citG) to form both adenine and 2'-(5-Triphosphoribosyl)-3'-dephospho-CoA. In this pathway, all enzymes are essential for the cell growth. Biosynthetic pathway for producing CoA is same for most organisms (with exception of differences in the functionality of involved enzymes). In plants, every step is catalyzed by monofunctional enzymes instead of biofunctional enzymes.

The CoA biosynthesis requires compounds from two other pathways: aspartate metabolism and valine biosynthesis. It requires a Beta-Alanine and R-pantoate. The compound (R)-pantoate is generated in two reactions, as shown by the interaction of alpha-ketoisovaleric acid, 5,10 methylene-THF and water through a 3-methyl-2-oxobutanoate hydroxymethyltransferase resulting in a tetrahydrofolic acid and a 2-dehydropantoate. 2-dehydropantoate interacts with hydrogen through a NADPH driven acetohydroxy acid isomeroreductase resulting in the release of NADP and R-pantoate. On the other hand L-aspartic acid interacts with a hydrogen ion and gets decarboxylated through an Aspartate 1- decarboxylase resulting in a carbon dioxide and a Beta-alanine. Beta-alanine and R-pantoate interact with an ATP driven pantothenate synthetase resulting in pyrophosphate, AMP, hydrogen ion and pantothenic acid. Pantothenic acid is phosphorylated through a ATP-driven pantothenate kinase resulting in a ADP, a hydrogen ion and D-4'-Phosphopantothenate. The latter interacts with a CTP and a L-cysteine resulting in a fused 4'phosphopantothenoylcysteine decarboxylase and phosphopantothenoylcysteine synthetase resulting in a hydrogen ion, a pyrophosphate, a CMP and 4-phosphopantothenoylcysteine. The latter compound interacts with a hydrogen ion through a fused 4'-phosphopantothenoylcysteine decarboxylase and phosphopantothenoylcysteine synthetase resulting in the release of carbon dioxide and 4-phosphopantetheine. 4-phosphopantetheine reacts with ATP, hydrogen ion and an phosphopantetheine adenylyltransferase resulting in a release of pyrophosphate, and dephospho-CoA. Dephospho-CoA reacts with an ATP driven dephospho-CoA kinase resulting in a ADP , a hydrogen ion and a Coenzyme A. Dephospho-CoA also reacts with 2-(5''-triphosphoribosyl)-3'-dephosphocoenzyme-A synthase (citG) to form both adenine and 2'-(5-Triphosphoribosyl)-3'-dephospho-CoA. In this pathway, all enzymes are essential for the cell growth. Biosynthetic pathway for producing CoA is same for most organisms (with exception of differences in the functionality of involved enzymes). In plants, every step is catalyzed by monofunctional enzymes instead of biofunctional enzymes.

The CoA biosynthesis requires compounds from two other pathways: aspartate metabolism and valine biosynthesis. It requires a Beta-Alanine and R-pantoate. The compound (R)-pantoate is generated in two reactions, as shown by the interaction of alpha-ketoisovaleric acid, 5,10 methylene-THF and water through a 3-methyl-2-oxobutanoate hydroxymethyltransferase resulting in a tetrahydrofolic acid and a 2-dehydropantoate. 2-dehydropantoate interacts with hydrogen through a NADPH driven acetohydroxy acid isomeroreductase resulting in the release of NADP and R-pantoate. On the other hand L-aspartic acid interacts with a hydrogen ion and gets decarboxylated through an Aspartate 1- decarboxylase resulting in a carbon dioxide and a Beta-alanine. Beta-alanine and R-pantoate interact with an ATP driven pantothenate synthetase resulting in pyrophosphate, AMP, hydrogen ion and pantothenic acid. Pantothenic acid is phosphorylated through a ATP-driven pantothenate kinase resulting in a ADP, a hydrogen ion and D-4'-Phosphopantothenate. The latter interacts with a CTP and a L-cysteine resulting in a fused 4'phosphopantothenoylcysteine decarboxylase and phosphopantothenoylcysteine synthetase resulting in a hydrogen ion, a pyrophosphate, a CMP and 4-phosphopantothenoylcysteine. The latter compound interacts with a hydrogen ion through a fused 4'-phosphopantothenoylcysteine decarboxylase and phosphopantothenoylcysteine synthetase resulting in the release of carbon dioxide and 4-phosphopantetheine. 4-phosphopantetheine reacts with ATP, hydrogen ion and an phosphopantetheine adenylyltransferase resulting in a release of pyrophosphate, and dephospho-CoA. Dephospho-CoA reacts with an ATP driven dephospho-CoA kinase resulting in a ADP , a hydrogen ion and a Coenzyme A. Dephospho-CoA also reacts with 2-(5''-triphosphoribosyl)-3'-dephosphocoenzyme-A synthase (citG) to form both adenine and 2'-(5-Triphosphoribosyl)-3'-dephospho-CoA. In this pathway, all enzymes are essential for the cell growth. Biosynthetic pathway for producing CoA is same for most organisms (with exception of differences in the functionality of involved enzymes). In plants, every step is catalyzed by monofunctional enzymes instead of biofunctional enzymes.

The CoA biosynthesis requires compounds from two other pathways: aspartate metabolism and valine biosynthesis. It requires a Beta-Alanine and R-pantoate. The compound (R)-pantoate is generated in two reactions, as shown by the interaction of alpha-ketoisovaleric acid, 5,10 methylene-THF and water through a 3-methyl-2-oxobutanoate hydroxymethyltransferase resulting in a tetrahydrofolic acid and a 2-dehydropantoate. 2-dehydropantoate interacts with hydrogen through a NADPH driven acetohydroxy acid isomeroreductase resulting in the release of NADP and R-pantoate. On the other hand L-aspartic acid interacts with a hydrogen ion and gets decarboxylated through an Aspartate 1- decarboxylase resulting in a carbon dioxide and a Beta-alanine. Beta-alanine and R-pantoate interact with an ATP driven pantothenate synthetase resulting in pyrophosphate, AMP, hydrogen ion and pantothenic acid. Pantothenic acid is phosphorylated through a ATP-driven pantothenate kinase resulting in a ADP, a hydrogen ion and D-4'-Phosphopantothenate. The latter interacts with a CTP and a L-cysteine resulting in a fused 4'phosphopantothenoylcysteine decarboxylase and phosphopantothenoylcysteine synthetase resulting in a hydrogen ion, a pyrophosphate, a CMP and 4-phosphopantothenoylcysteine. The latter compound interacts with a hydrogen ion through a fused 4'-phosphopantothenoylcysteine decarboxylase and phosphopantothenoylcysteine synthetase resulting in the release of carbon dioxide and 4-phosphopantetheine. 4-phosphopantetheine reacts with ATP, hydrogen ion and an phosphopantetheine adenylyltransferase resulting in a release of pyrophosphate, and dephospho-CoA. Dephospho-CoA reacts with an ATP driven dephospho-CoA kinase resulting in a ADP , a hydrogen ion and a Coenzyme A. Dephospho-CoA also reacts with 2-(5''-triphosphoribosyl)-3'-dephosphocoenzyme-A synthase (citG) to form both adenine and 2'-(5-Triphosphoribosyl)-3'-dephospho-CoA. In this pathway, all enzymes are essential for the cell growth. Biosynthetic pathway for producing CoA is same for most organisms (with exception of differences in the functionality of involved enzymes). In plants, every step is catalyzed by monofunctional enzymes instead of biofunctional enzymes.

The CoA biosynthesis requires compounds from two other pathways: aspartate metabolism and valine biosynthesis. It requires a Beta-Alanine and R-pantoate. The compound (R)-pantoate is generated in two reactions, as shown by the interaction of alpha-ketoisovaleric acid, 5,10 methylene-THF and water through a 3-methyl-2-oxobutanoate hydroxymethyltransferase resulting in a tetrahydrofolic acid and a 2-dehydropantoate. 2-dehydropantoate interacts with hydrogen through a NADPH driven acetohydroxy acid isomeroreductase resulting in the release of NADP and R-pantoate. On the other hand L-aspartic acid interacts with a hydrogen ion and gets decarboxylated through an Aspartate 1- decarboxylase resulting in a carbon dioxide and a Beta-alanine. Beta-alanine and R-pantoate interact with an ATP driven pantothenate synthetase resulting in pyrophosphate, AMP, hydrogen ion and pantothenic acid. Pantothenic acid is phosphorylated through a ATP-driven pantothenate kinase resulting in a ADP, a hydrogen ion and D-4'-Phosphopantothenate. The latter interacts with a CTP and a L-cysteine resulting in a fused 4'phosphopantothenoylcysteine decarboxylase and phosphopantothenoylcysteine synthetase resulting in a hydrogen ion, a pyrophosphate, a CMP and 4-phosphopantothenoylcysteine. The latter compound interacts with a hydrogen ion through a fused 4'-phosphopantothenoylcysteine decarboxylase and phosphopantothenoylcysteine synthetase resulting in the release of carbon dioxide and 4-phosphopantetheine. 4-phosphopantetheine reacts with ATP, hydrogen ion and an phosphopantetheine adenylyltransferase resulting in a release of pyrophosphate, and dephospho-CoA. Dephospho-CoA reacts with an ATP driven dephospho-CoA kinase resulting in a ADP , a hydrogen ion and a Coenzyme A. Dephospho-CoA also reacts with 2-(5''-triphosphoribosyl)-3'-dephosphocoenzyme-A synthase (citG) to form both adenine and 2'-(5-Triphosphoribosyl)-3'-dephospho-CoA. In this pathway, all enzymes are essential for the cell growth. Biosynthetic pathway for producing CoA is same for most organisms (with exception of differences in the functionality of involved enzymes). In plants, every step is catalyzed by monofunctional enzymes instead of biofunctional enzymes.