A proton pump is an integral membrane protein that is capable of moving protons across a biological membrane. Mechanisms are based on conformational changes of the protein structure or on the Q cycle.
An overview of Proton Pump
Proton pump, also known as gastric acid pump, is essentially an H+/K+-ATP enzyme that is a kind of transmembrane protein. Proton pump exists in gastric mucosa cells and is able to transport protons through the cell cytoplasmic membrane and acidify intracellular compartments, which plays a vital role in the regulation of cell pH. Structurally, proton pump consists of a peripheral domain and an integral domain. The peripheral domain is responsible for hydrolysis while the integral domain regulates the proton exchange.
Inhibition of Proton Pump
Proton pump inhibitors are a kind of potent anti-acid drugs acting on H+/K+-ATP enzyme, which are widely applied in the treatment of various acid-related diseases. Since the first proton-pump inhibitor omeprazole was synthesized by researchers in the 1980s, the cure rate of digestive diseases such as duodenal ulcer, gastric and gastroesophageal reflux disease (GERD) has been greatly improved. Proton pump inhibitors can exert function in the treatment of GERD due to their profound and consistent inhibitory effect on acid secretion. The antioxidant effects of proton pump inhibitors can prevent oxidative stress reactions in the cardiovascular system. After decades of promotion and development, many proton pump inhibitors have been put into clinical use, including omeprazole, lansoprazole, pantoprazole, rabeprazole, esomeprazole, revaprazan, ilaprazole and dexlansoprazole.
Proton Pump and diseases
Since proton pump was discovered in parietal cells, the structure and acid secretion function of proton pumps have been well known after decades of exploration. Proton pump is responsible for neutral intracellular pH, an acidic luminal pH, and an acidic extracellular pH. It is believed that the low extracellular pH of tumors leads to the dissolution of extracellular matrix, contributing to tumor invasion and dissemination. It can be easily speculated that the disorder of proton pump is associated with a variety of acid-related upper digestive diseases, including duodenal ulcer, peptic ulcer, gastric and GERD. Therefore, lots of proton pump inhibitors have been approved and adopted for the treatment of these diseases.
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