Diazepam binding inhibitor (acyl-CoA-binding protein) (DBI)

Diazepam binding inhibitor (DBI), also known as acyl-CoA-binding protein (ACBP), is a highly conserved, multifunctional protein found in central and peripheral tissues[1][7]. In the nervous system, it acts as an endogenous ligand at the benzodiazepine recognition site on GABA(_A) receptors, modulating inhibitory neurotransmission by either potentiating or inhibiting GABAergic signaling depending on context — activity attributed to specific DBI-derived peptides sometimes termed \"endozepines\"[2][3]. In peripheral tissues and cells, DBI/ACBP is crucial for intracellular lipid metabolism, serving as a transporter and pool former for medium- and long-chain acyl-CoA esters and influencing processes such as fatty acid synthesis, β-oxidation, and steroidogenesis[4][1][7]. It also regulates the secretion of cholecystokinin and pancreatic enzymes, thus linking neuroendocrine and metabolic functions. DBI's diverse roles position it at the intersection of metabolism, neurobiology, and endocrine regulation, which makes it a protein of interest for several disease processes including epilepsy, metabolic syndrome, and possibly neurodegeneration and psychiatric disorders[1][2][7].

Other names

Acyl-CoA-binding proteinACBPEndozepineACBD1Cholecystokinin-releasing peptideCCK-RPEpididymis secretory sperm-binding proteinGABA receptor modulator

Endogenous allosteric modulation (DBI modulates GABA(A) receptor activity via the benzodiazepine site — direct functional evidence for positive and negative modulation in different contexts); Displacement of exogenous benzodiazepines and beta-carbolines; Intracellular transport and sequestration of acyl-CoA esters