Recombinant Nucleosome (E. coli-derived)

What it means: E. coli — this protein was produced in E. coli, determining its post-translational modification profile and application suitability.

Why it matters:

• Insect cell (Sf9) systems support post-translational processing required for kinase activity and complex formation; HEK293 supports human-like glycosylation; E. coli yields high-quantity non-glycosylated protein.
• For assays measuring native enzymatic activity (kinase, phosphodiesterase, deacetylase), the expression system directly affects the quality and accuracy of results.

How to interpret here: Verify E. coli is compatible with your assay requirements, particularly for enzyme kinetics and cell-based applications.

What it means: ≥90% — protein purity was determined by SDS-PAGE and/or HPLC to confirm the proportion of correctly-sized target protein in the preparation.

Why it matters:

• High purity is critical for enzyme kinetics, inhibitor IC50 determinations, and SPR/BLI where contaminants would introduce signal artefacts or change the apparent kinetic parameters.
• Consistent lot-to-lot purity underpins reproducibility in hit-to-lead screening campaigns.

How to interpret here: ≥90% as determined by SDS-PAGE. Lot-specific QC data is provided on the Certificate of Analysis with each shipment.

What it means: Not applicable (BSL-1) — this protein has been classified under BSL-1 safety requirements, the lowest biosafety classification.

Why it matters:

• BSL-1 proteins pose no known risk to healthy adult laboratory workers and do not require specialised containment or personal protective equipment beyond standard laboratory practice.
• Confirms suitability for use in standard biochemistry or molecular biology laboratories without institutional BSL-2 or higher facility requirements.

How to interpret here: Standard laboratory safety practices apply. Review the product SDS/Datasheet for handling precautions specific to this compound.

What it means: This protein spans amino acids Histone H2A: 2-130(end); Histone H2B: 2-126(end); Histone H3: 2-136(end); Histone H4: 2-103(end) of the target protein, covering the region used for expression and purification.

Why it matters:

• The expressed amino acid region determines which functional domains are present — catalytic domains, binding interfaces, or regulatory regions — affecting activity and assay design.
• For fragment proteins, confirm the region includes your domain of interest (active site, binding pocket, substrate site) before ordering.

How to interpret here: Amino acids Histone H2A: 2-130(end); Histone H2B: 2-126(end); Histone H3: 2-136(end); Histone H4: 2-103(end) are included in this construct. Cross-reference with the UniProt domain annotation to confirm coverage of your target region.

What it means: UniProt accession Histone H2A: Q7L7L0; Histone H2B: Q16778; Histone H3: P68431; Histone H4: P62805 is the canonical identifier for this protein in the Universal Protein Resource database.

Why it matters:

• UniProt provides the canonical sequence, domain architecture, known mutations, disease associations, and curated literature — essential for designing inhibitor assays.
• Use the accession for database cross-referencing in publications and to identify known binding partners and substrate sequences.

How to interpret here: Visit uniprot.org/Histone H2A: Q7L7L0; Histone H2B: Q16778; Histone H3: P68431; Histone H4: P62805 to retrieve the full protein sequence, verify the expressed amino acid region, and review annotated active site residues and known inhibitors.