Isolation of Putative Benzodiazepine Receptors from Rat Brain Membranes by Affinity Chromatography

Authors


Address correspondence and reprint requests to Prof. Antonio Lucacchini, Istituto di Chimica Biologica, Via Roma 55, 56100 Pisa, Italy.

Abstract

Abstract: The benzodiazepine receptor from rat brain was solubilised and purified 5200-fold by affinity chromatography. The affinity column contained an immobilized benzodiazepine (delorazepam) and biospecific elution with 6 mm-chlorazepate was achieved. The purified receptor is apparently homogeneous in SDS-polyacrylamide gel electrophoresis. The native protein had a molecular weight of 240,000, and the subunit one of 60,000. The dissociation constant (KD) is 8 nm for [3H]diazepam. A correlation exists between the value of affinity obtained for benzodiazepine derivatives and their known pharmacological effectiveness.

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