pH-dependent membrane interaction

pH-dependent membrane interaction is a general term for the phenomenon where the binding or insertion of peptides, proteins, or other molecules into lipid membranes is regulated by the pH of the environment[1][2][3][4][7]. These interactions often rely on the protonation or deprotonation of certain amino acid side chains (such as histidine or glutamate), which alters the molecule's charge and affinity for the membrane. This property is being exploited in the design of peptides that selectively target or anchor to acidic environments such as tumors, inflamed tissue, or infected sites. Well-studied examples include engineered peptides like pHLIP and TYPE7, which insert into cell membranes at low pH and can be used for targeted drug delivery or modulation of membrane proteins[2][3]. The phenomenon is not a discrete target but rather a strategy that enables selectivity in hostile or abnormal microenvironments.