[Biochemical and electron crystallographic studies of gastric proton pump]

V-type pumps are ATP-driven pumps found in the vacuolar membranes of plants, yeast, endosomal and lysosomal membranes of animal cells, plasma membranes of a few specialized eukaryotic cells, and some prokaryotes. They are also known as the V1Vo-ATPase, that couple ATP hydrolysis to transport protons against a concentration gradient.
The peripheral or cytosolic V1 domain with eight subunits is involved in ATP hydrolysis. The integral or transmembrane V0 domain containing at least five subunits...

ATP-driven pumps, also known as transport ATPases, are integral membrane proteins. They have binding sites for ATP located on the membrane's cytosolic side and the ion-conducting domain in the transmembrane region. These pumps use the free energy released from ATP hydrolysis to move the solutes across cell membranes against an electrochemical gradient.
There are four main types of ATP-driven pumps - P-type, V-type, F-type, and ABC transporter. All these pumps are of varying complexities and...

The human body carefully regulates the internal pH of different organs to maintain homeostasis. For example, while the blood plasma maintains a neutral pH of 7, the stomach lumen has an acidic pH of 1.5 - 3.5. The low pH of stomach lumen helps kill pathogens in the food and break down complex food molecules.
The acid-secreting gastric mucosal epithelial cells (parietal cells) lining the stomach lumen maintain the low pH in the lumen. Numerous ion transporters and channels on these parietal...

Peptic ulcers, often induced by H. pylori infections or NSAID usage, arise from disruptions in the delicate balance of gastric acid production. Peptic ulcers stem from heightened gastric acid levels due to H. pylori infections or NSAID use. The protective mucus layer diminishes in the presence of these factors, allowing gastric acid to erode the stomach lining and form ulcers.
Gastric acid, a potent cocktail of hydrogen and chloride ions, is produced in specialized parietal cells within the...

Gastric motility is the coordinated contraction and relaxation of stomach muscles that convert ingested food into chyme, a semi-liquid substance ready for further digestion in the intestines. The process begins with the vagus nerve inducing the relaxation of the smooth muscles in the fundus and body of the stomach, allowing these regions to expand and accommodate up to approximately 1.5 liters of food and liquid.
Peristaltic Waves and Chyme Formation
Upon food entry, the stomach initiates...

The P-type pumps are a large family of integral membrane transporter ATPases. They are divided into five major types based on substrate specificity, from I to V.
A typical P-type pump has three cytosolic domains: nucleotide-binding (N), phosphorylation (P), and activator (A) domains. These domains are connected to the membrane-spanning helices by short amino acid segments. ATP hydrolysis and covalent phosphoenzyme intermediate formation are crucial parts of the catalytic cycle. At the highly...