P-glycoprotein 1 (permeability glycoprotein, P-gp or Pgp) also known as multidrug resistance protein 1 (MDR1) or ATP-binding cassette sub-family B member 1 (ABCB1) or cluster of differentiation 243 (CD243) is an important protein of the cell membrane that pumps many foreign substances out of cells. More formally, it is an ATP-dependent efflux pump with broad substrate specificity. It exists in animals, fungi and bacteria and likely evolved as a defense mechanism against harmful substances. P-gp is extensively distributed and expressed in the intestinal epithelium where it pumps xenobiotics (such as toxins or drugs) back into the intestinal lumen, in liver cells where it pumps them into bile ducts, in the cells of the proximal tubular of the kidney where it pumps them into urine-conducting ducts, and in the capillary endothelial cells comprising the blood–brain barrier and blood-testis barrier, where it pumps them back into the capillaries. Some cancer cells also express large amounts of P-gp, which renders these cancers multi-drug resistant. P-gp is a glycoprotein that in humans is encoded by the ABCB1 gene (1280aa). P-gp is a well-characterized ABC-transporter (which transports a wide variety of substrates across extra- and intracellular membranes) of the MDR/TAP subfamily. ABC proteins transport various molecules across extra- and intra-cellular membranes. ABC genes are divided into seven distinct subfamilies (ABC1, MDR/TAP, MRP, ALD, OABP, GCN20, White). This protein is a member of the MDR/TAP subfamily. Members of the MDR/TAP subfamily are involved in multidrug resistance. P-gp is an ATP-dependent drug efflux pump for xenobiotic compounds with broad substrate specificity. It is responsible for decreased drug accumulation in multidrug-resistant cells and often mediates the development of resistance to anticancer drugs. This protein also functions as a transporter in the blood–brain barrier. P-gp is a 170kD transmembrane glycoprotein, which includes 10-15kD of N-terminal glycosylation. The N-terminal half of the molecule contains 6 transmembrane domains, followed by a large cytoplasmic domain with an ATP-binding site, and then a second section with 6 transmembrane domains and an ATP-binding site that shows over 65% of amino acid similarity with the first half of the polypeptide. Substrate enters P-gp either from an opening within the inner leaflet of the membrane or from an opening at the cytoplasmic side of the protein. ATP binds at the cytoplasmic side of the protein. Following binding of each, ATP hydrolysis shifts the substrate into a position to be excreted from the cell. Release of the phosphate (from the original ATP molecule) occurs concurrently with substrate excretion. ADP is released, and a new molecule of ATP binds to the secondary ATP-binding site. Hydrolysis and release of ADP and a phosphate molecule resets the protein, so that the process can start again. P-glycoprotein is expressed primarily in certain cell types in the liver, pancreas, kidney, colon, and jejunum. The activity of the transporter can be determined by both membrane ATPase and cellular calcein assays.
Source:Recombinant protein corresponding to aa1036-1280 from human PgP, fused to his-tag, expressed in E. coli.
Molecular Weight:~15kD
Applications:Suitable for use in ELISA and Western Blot. Other applications not tested.
Recommended Dilution:ELISA: coat at 50-200ng protein/well and detect with appropriate antibodies
Western Blot: load 50-200ng protein/lane for detection with appropriate antibodies
Optimal dilutions to be determined by the researcher.
Storage and Stability:May be stored at 4°C for short-term only. Aliquot to avoid repeated freezing and thawing. Store at -20°C. Aliquots are stable for 12 months. For maximum recovery of product, centrifuge the original vial after thawing and prior to removing the cap.
仕様
Size：2ug
Source Antigen：Recombinant, E. coli
Grade：Highly Purified
Purity：Highly Purified (~95%)
Form：Supplied as a liquid in 100mM sodium phosphate, pH 4.5, 10mM sodium chloride, 0.5% trehalose, 6M urea.
