title: A computer controlled device to facilitate studies of the kinetics of ligand-binding: binding of diazepam to bovine brain membranes.
abstract: A device to facilitate kinetic receptor filtration assays is described. The receptor containing membranes and the labeled ligand are placed in two separate syringes and are rapidly mixed into a collecting syringe using a pneumatic ram. Shortly after the start of mixing, a pneumatically controlled valve switches the collecting syringe containing the receptor-ligand mixture to the filtration unit. Filtration is performed on glass/microfiber filters or equivalent by pushing the plunger of the collecting syringe by a stepper motor. A valve positioner controlling several valves allows the filtered membranes to be washed and dried by pressure in any user programmable sequence. Further filtration of the receptor-ligand mixture can be programmed at selected time points. The entire system is controlled by an IBM-PC. With this system, the association and dissociation of diazepam from crude bovine-brain membranes has been studied at 4 degrees C. The dissociation shows a biphasic pattern with half lifes of 1.3 and more than 23 minutes respectively. Association appears to be into a single compartment.
authors.affiliation: Institut für Klinische Chemie, Universitätsspital, Zürich, Switzerland.
authors.forename: R A
authors.initials: RA
authors.lastname: Lutz
authors.forename: F P
authors.initials: FP
authors.lastname: Steiner
authors.forename: D
authors.initials: D
authors.lastname: Benke
authors.forename: S
authors.initials: S
authors.lastname: Mertens
authors.forename: E
authors.initials: E
authors.lastname: Minder
authors.forename: D
authors.initials: D
authors.lastname: Vonderschmitt
mesh_terms: D000818:Animals; D001331:Automation; D001921:Brain / Q000378:metabolism*; D002417:Cattle; D003975:Diazepam / Q000378:metabolism*; D005374:Filtration / Q000295:instrumentation; D066298:In Vitro Techniques; D007700:Kinetics; D008566:Membranes / Q000378:metabolism; D008838:Microcomputers; D011869:Radioligand Assay / Q000295:instrumentation / Q000379:methods*
chemical_list: D003975:Diazepam