Molecular biology of diazepam binding inhibitor

The techniques of molecular biology have rapidly advanced the field of neuropharmacology in recent years. Some of these advantages are presented briefly, followed by an example of the power of nucleic acid analysis: specifically the characterization of the diazepam binding inhibitor (DBI). The diazepam binding inhibitor is a putative endogenous ligand for a regulatory site on the gamma-aminobutyric acid, type A receptor. The complementary deoxyribonucleic acid (cDNA) encoding this 87-residue peptide has been isolated, sequenced and expressed in heterologous systems. Diazepam binding inhibitor is encoded by a multigene family and is expressed in a tissue-specific manner, although expression is not limited to the brain.