P-gp PREDIVEZ^™ Vesicular Transport Assay Kit

"Another barrier crossed. New P-gp vesicular transport assay!"

The P-gp PREDIVEZ^™ kit is a breakthrough in P-gp interaction assessment. This assay measures drug-transporter interaction in membrane vesicles expressing human P-gp or rat Mdr1b.

Background:

FDA requires studies to investigate the interaction of drug candidates with P-gp. The new P-gp PREDIVEZ^™ kit is a revolutionary method that allows a faster and more cost effective measurement than lower throughput cellular assays, such as Caco-2, MDCK-MDR1 or LLC-PK MDR1 cell-based systems.

The vesicular transport assay is a widely-used tool to study drug-transporter interactions in a simple and high throughput assay setup, and offers the choice of direct or indirect measurement options. Membranes prepared from human or insect cells overexpressing the efflux transporter contain inside-out membrane vesicles in which the transported compound accumulates. Typical detection methods include scintillation counting, fluorescence or LC-MS. The indirect vesicular transport assay is an inhibitory-type approach, performed with cold test compounds. It provides information on any interaction between the transporter and the drug candidate that would affect the transport of the reporter substrate.

P-gp PREDIVEZ^™ kit theory and data:

P-gp (ABCB1, MDR1) is the most commonly studied ABC transporter with important roles not only in tumor multidrug resistance but in the ADMETox properties of drugs and nutrients. As most of the substrates of P-gp are highly membrane permeable, the challenge was to develop a vesicular transport assay with a low permeability reporter substrate. SOLVO's new P-gp PREDIVEZ^™ Kit operates with a low permeability cationic radio-labeled substrate that is transported by both MDR1 and ratMdr1b transporters. The typical dynamic range (cpms in ATP+/cpms in ATP-) is ~ 10 in the P-gp and ~ 3 in the ratMdr1b assay.

Human P-gp PREDIVEZ^™ kit works with human membrane vesicles while the rat Mdr1b PREDIVEZ^™kit contains insect membrane preparation expressing the rodent ABC transporter.

Human P-gp

Compound	LY335979	Cs A	Verapamil	Ketoconazole	Erythromycin	Digoxin
IC50 / µM	0.01	0.11	2.28	6.81	34.08	191.8

Rat Mdr1b

Compound	LY335979	GF 120918	Cyclosporin A	Ketoconazole	Verapamil	Digoxin
IC50 / µM	0.3	0.3	0.43	1.3	9.5	320

P-gp PREDIVEZ^™ kit components:
P-gp PREDIVEZ^™ VT kit and rat Mdr1b PREDIVEZ^™ VT kits are available in three sizes: 3, 6 and 9 compounds. Each kit contain sufficient amount of reagents and membrane preparation for testing 3 compounds per 96-well plate. Negative control membranes and positive control reference materials are also included. Each kit is accompanied by a CD that includes the assay protocol, Excel spreadsheet with data processing template, MSDS and reference curves with known interactors.

The price of the kit includes the cost of the radio labeled reporter substrate, which is shipped separately. The labeled reporter compound comes in a single size package, sufficient for testing 9 compounds. PREDIVEZ^™ VT kits are also available without the labeled reporter compound.