Proton transport

Proton transport refers to the movement of protons (H⁺ ions) across biological membranes, a fundamental process critical to cellular bioenergetics, pH regulation, and signaling[4][2][6][8]. It is executed by a variety of membrane proteins—including proton pumps (e.g., H⁺/K⁺ ATPase in the stomach, V-ATPases in endomembranes, and mitochondrial complex proteins), channels (such as voltage-gated proton channels), and some rhodopsins in microbes[3][4]. Dysregulation of proton transport is implicated in diseases ranging from ulcers and acid reflux (via gastric proton pump overactivity) to cancer and neurodegeneration (through mitochondrial proton gradient disruption)[4][6][9]. Proton pump inhibitors are key drugs that target specific enzymes (such as H⁺/K⁺ ATPase) involved in this process[9]. The precise molecular mechanism depends on the specific protein, but typically involves a chain of amino acids or water molecules forming a "proton wire," allowing rapid and selective H⁺ transfer across hydrophobic membranes[5][7][1].

Inhibition of ATPase-mediated proton transport (by proton pump inhibitors) Disruption of proton gradients, leading to altered pH homeostasis