Ligand transport

Ligand transport refers to the fundamental biological process of translocating molecules—including ions, metabolites, and pharmaceutical compounds—across biological membranes or within systemic circulation [1, 9]. This functional category encompasses a vast array of specialized proteins such as the Solute Carrier (SLC) superfamily, ATP-Binding Cassette (ABC) transporters, and transport receptors that facilitate receptor-mediated endocytosis [1, 2, 7, 13]. Because "Ligand transport" describes a broad biological mechanism rather than a discrete molecular target, it is considered too broad for specific drug targeting; instead, pharmaceutical research focuses on individual proteins within this hierarchy [10, 11]. Dysregulation of specific ligand transport systems is implicated in various pathologies, including multidrug resistance in cancer (e.g., via P-glycoprotein), metabolic disorders, and neurological conditions [2, 3, 12]. Drugs typically interact with these systems as inhibitors or substrates to modulate the movement of specific ligands, thereby restoring homeostasis or altering drug distribution [2, 13].

Other names

Biological transportMolecular transportSolute transportSubstrate translocationCarrier-mediated transportTranscellular transport

Drugs typically act as competitive or non-competitive inhibitors, allosteric modulators, or substrates of specific transport proteins to alter the flux of physiological or pharmacological ligands across biological membranes.