Cat. No.
MABL-337
Application
FC, IF, IHC
Isotype
Engineer antibody
Species Reactivity
Human
Clone No.
5D3
From
Recombinant Antibody
Specificity
This antibody recognizes and binds a conformation-sensitive external epitope of ABCG2 on living cells. ABCG2 is a broad substrate specificity ATP-dependent transporter from the ATP-binding cassette (ABC) family that actively extrudes a wide variety of physiological compounds, dietary toxins and xenobiotics from cells. (PMID:11306452, 12958161, 19506252, 20705604, 28554189, 30405239, 31003562). The human ABCG2 protein is an important primary active transporter for hydrophobic compounds in several cell types, and its overexpression causes multidrug resistance in tumors (PMID: 15557326). ABCG2 is associated with drug resistance in acute myeloid leukemia (AML) (PMID: 12393637). ABCG2 expression may also have potential as a marker that identifies human limbal epithelial stem cells (PMID: 15625123).
Alternative Names
CD338; CDw338; ABCP; BCRP; BCRP1; MXR; Breast cancer resistance protein; mitoxantrone resistance; Urate exporter; Broad substrate specificity ATP-binding cassette transporter ABCG2; ATP-binding cassette sub-family G member 2; Mitoxantrone resistance-associated protein; Placenta-specific ATP-binding cassette transporter
UniProt
Q9UNQ0
Immunogen
The original antibody was generated by immunizing mice with intact mouse 3T3 fibroblasts expressing the human ABCG2 protein.
Application Notes
This antibody is recommended for identification of human ACBG2 in a sample. This antibody was used in the immunostaining of bone marrow cells to establish a direct link between the SP phenotype and ABCG2 expression (PMID: 11533706). The IgG2b version of this antibody was used to identify AML cell lines that express ABCG2 protein using flow cytometry. This antibody inhibits ABCG2 function, presumably by binding to an external epitope and preventing conformational changes in the transporter, and therefore provides a specific inhibitor assay for ABCG2 function (PMID: 12393637). The SP (side population phenotype) analysis of limbal epithelial cells using 5D3 and TPS-A showed that both 5D3 and TPS-A effectively inhibit Hoechst 33342 dye efflux from these cells (PMID: 15135043). Conformational changes in the ABCG2 multidrug transporter result in the modification of its interaction with 5D3 antibody. 
This antibody therefore cannot be used to identify human ABCG2 in an immunoblot/western blot assay. The 
binding of this antibody was maximum in the presence of ATP, ADP, or Ko143, whereas the non_x0002_hydrolysable ATP analog, adenosine 5'-(beta, gamma-imido)triphosphate (AMP-PNP), and nucleotide 
trapping by vanadate decreased antibody binding. In membranes expressing the ABCG2-K86M mutant, 
ATP, ADP, and AMP-PNP decreased, whereas Ko143 increased the binding of this antibody. 5D3 can be used 
as a sensitive tool to reveal intramolecular changes, reflecting ATP binding, the formation of a catalytic 
intermediate, or substrate inhibition within the transport cycle of the ABCG2 protein (PMID: 15557326). This 
antibody was also used in a study involving localization of ABCG2 mitoxantrone resistance-associated 
protein in normal tissues using immunohistochemistry (PMID: 15990223). This antibody was also used in 
determining ABCG2 expression using immunofluorescent staining (PMID: 15625123).
Antibody First Published
Zhou et al. The ABC transporter Bcrp1/ABCG2 is expressed in a wide variety of stem cells and is a molecular determinant of the side-population phenotype. Nat Med. 2001 Sep;7(9):1028-34. PMID:11533706
Note on publication
Describes the use of this antibody in the immunostaining of bone marrow cells expressing ABCG2.
Size
100 μg Purified antibody.
Concentration
1 mg/ml.
Purification
Protein A affinity purified
Buffer
PBS with 0.02% Proclin 300.
Storage Recommendation
Store at 4⁰C for up to 3 months. For longer storage, aliquot and store at - 20⁰C.

