P-type adenosine triphosphatase (P-type ATPase) (P-type ATPase)

P-type ATPases are a large and ubiquitous superfamily of membrane-bound transporters that utilize the energy derived from ATP hydrolysis to move cations and phospholipids across biological membranes against their electrochemical gradients [1]. They are defined by a unique catalytic mechanism involving the formation of a covalent phosphorylated aspartyl intermediate, transitioning between E1 and E2 conformational states [2, 5]. This family includes essential pumps such as the sodium-potassium pump (Na+/K+-ATPase), which maintains resting membrane potential, and the gastric proton pump (H+/K+-ATPase), which is responsible for stomach acidification [1]. These proteins play fundamental roles in physiological processes ranging from muscle contraction and nerve impulse transmission to nutrient absorption and heavy metal detoxification [2]. Because of their central role in homeostasis, P-type ATPases are significant clinical targets; for instance, cardiac glycosides like digoxin inhibit the Na+/K+-ATPase to treat heart failure, while proton pump inhibitors (PPIs) target the H+/K+-ATPase to manage acid-related gastrointestinal disorders [3, 4]. Citations: [1] Morth JP, et al. (2011) Nat Rev Mol Cell Biol; [2] Bublitz M, et al. (2011) J Intern Med; [3] StatPearls, Digoxin; [4] StatPearls, Proton Pump Inhibitors; [5] UniProt, P-type ATPase superfamily.

Other names

E1-E2 ATPaseP-type ion-transporting ATPasePhosphorylation-type ATPaseP-type pump

P-type ATPases are inhibited by drugs that bind to specific conformational states (E1 or E2) of the pump's catalytic cycle. For example, cardiac glycosides bind to the extracellular side of the E2-P state of the Na+/K+-ATPase to inhibit ion exchange, while proton pump inhibitors (PPIs) covalently bind to cysteine residues in the H+/K+-ATPase to irreversibly block gastric acid secretion [3, 4].