Recombinant JARID1B / KDM5B protein

Aliases: Lysine Demethylase 5B, Cancer/Testis Antigen 31, Retinoblastoma-Binding Protein 2 Homolog 1, Histone Demethylase JARID1B
Catalog No: 31432 Format: 20 µg $515 Buy
Catalog No: 31832 Format: 1 mg $4,300 Buy

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Expressed In: Sf9 cells Protein Species: Human


A representative Technical Data Sheet (TDS) is provided here. Please refer to the lot-specific TDS you will receive with your order for the lot-specific buffer contents and protein concentration.


Lysine (K)-specific demethylase 5B (KDM5B), also known as Jumonji, AT rich interactive domain 1B (JARID1B), is a histone demethylase that specifically demethylates lysine 4 of histone H3 (H3K4), thereby playing a central role in defining the histone code. KDM5B demethylates trimethylated, dimethylated and monomethylated H3K4. It does not demethylate histone H3K9 or H3K27. KDM5B functions as a transcriptional corepressor for FOXG1B and PAX9. KDM5B induces the proliferation of breast cancer cells by repressing tumor suppressor genes such as BRCA1 and HOXA5. In contrast, it may act as a tumor suppressor for melanoma.

Application Notes

Recombinant JARID1B / KDM5B is suitable for use in the study of enzyme kinetics, inhibitor screening, and selectivity profiling.

Specific Activity: H3K4me3 demethylase.

Catalytic Rate: 20 turnovers/ enzyme molecule

Histone Demethylase Assay Conditions: 3.3 μM H3K4me3 (aa 1-21) peptide was incubated with different concentrations of recombinant JARID1B / KDM5B protein in reaction buffer containing 50 mM HEPES pH 7.5, 0.02% Triton X100, 100 μM 2OG, 100 μM Ascorbate, 50 μM (NH4)2Fe(SO4)2·6H2O, 1 mM TCEP for 1 hours at room temperature. HTRF and MALDI-TOF were used for detection.

Protein Details

Recombinant JARID1B / KDM5B (accession number NP_006609, full length) was expressed in Sf9 and contains an N-terminal FLAG-Tag with a molecular weight of 179.9 kDa. The recombinant protein is >75% pure by SDS-PAGE.


This protein is described in the following references:
Yamane K et al. (2007) Mol Cell 25:801-812
Barrett A et al. (2007) Int J Cancer 121:265-275


Recombinant JARID1B / KDM5B protein gel.
JARID1B / KDM5B protein was run on an 8% SDS-PAGE gel and stained with Coomassie blue.

Recombinant JARID1B / KDM5B protein activity assay.
3.3 μM H3K4me3 peptide was incubated with 50 nM JARID1B / KDM5B in reaction buffer for 2 hours at room temperature. The reaction product was detected by MALDI-TOF. Single 3.3 μM H3K4me3 peptide was used as negative control.

Catalytic Ability: 20 turnovers/ enzyme molecule

Recombinant JARID1B / KDM5B protein activity assay.
3.3 μM H3K4me3 peptide was incubated with JARID1B / KDM5B in reaction buffer for 1 hours at room temperature. JARID1B / KDM5B enzyme was used in a HTRF assay to determine enzyme linearity. Demethylated peptide (H3K4me2) was measured using H3K4me2-specific antibody.


Recombinant proteins in solution are temperature sensitive and must be stored at -80°C to prevent degradation. Avoid repeated freeze/thaw cycles and keep on ice when not in storage.


This product is guaranteed for 6 months from date of receipt.

This product is for research use only and is not for use in diagnostic procedures.