Recombinant PHF8-s protein

Aliases: KDM7B, PHD Finger Protein 8, Histone Lysine Demethylase PHF8, Jumonji C Domain-Containing Histone Demethylase 1F
Catalog No: 31461 Format: 20 µg
Expressed In: E. coli Protein Species: Human

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This product has been discontinued:
Please refer to our alternative product Catalog No. 31435

20 µg of recombinant PHF8-s protein expressed in E. coli cells and is supplied in 50 mM Tris pH 8.0, 400 mM NaCl.


PHF8 (PHD finger protein 8), also known as Lysine (K)-specific demethylase 7B (KDM7B) and JmjC domain-containing histone demethylation protein 1D-B (JHDM1DB), is a member of the JmjC-containing (Jumonji-C) class of histone demethylase proteins that are involved in the regulation of genome function through the removal of methyl groups from histones. PHF8 has two N-terminal domains, a PHD finger that binds trimethylated lysine 4 of histone H3 (H3K4me3) and a Jumonji domain that demethylates monomethylated H3 Lys9 (H3K9me1), Histone H3 dimethyl Lys9 (H3K9me2), Histone H3 dimethyl Lys27 (H3K27me2) (which are all modifications associated with transcriptional repression) and also Histone H3 dimethyl Lys36 (H3K36me2) via an oxidative pathway that requires the presence of Fe(II) and α-ketoglutarate as cofactors. Horton et al. (2010) demonstrated that, in the presence of H3K4me3, PHF8 shows enhanced demethylation of H3K9me2 on the same peptide. PHF8 enzyme is involved in various cellular processes, including DNA replication and repair and transcriptional regulation. Defects in the Jumonji domain of PHF8 lead to Siderius type X-linked mental retardation (MRXSSD).

PHF8-s is a truncated protein (aa 80-447) that includes the enzymatic Jumonji domain of PHF8. The truncated protein behaves as a promiscuous enzyme, losing substrate specificity when the PHD domain is deleted.

Application Notes

Recombinant PHF8-s is suitable for use in the study of enzyme kinetics, inhibitor screening, and selectivity profiling.

Protein Details

Recombinant PHF8-s, that includes amino acids 80-447 of PHF8 (accession number NP_055922) was generated by expressing a GST fusion protein containing residues 80-447 of PHF8 in E. coli cells, followed by affinity purification and cleavage of the GST-Tag with thrombin to produce a protein with an observed molecular weight of 42.592 kDa.


This protein is described in the following reference:
Horton J et al. (2010) Nature 17:38-43

PHF8-s Coomassie gel

PHF8-s protein gel.
PHF8-s (10 μg) run on a 4-20% SDS-PAGE gel and stained with Coomassie blue.

PHF8-s activity assay

PHF8-s activity assay.
Recombinant PHF8-s activity measured using a fluorescence-based demethylation assay.


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.