Histone variants are non-canonical histone proteins that differ from the core canonical histones by amino-acid sequence, post-translational modification (PTM) patterns, or specialized domains. They play essential roles in chromatin organization, genome regulation, DNA repair, transcriptional control, and chromosome segregation. Recombinant and purified histone variants, including H2A variants, H3 variants, linker H1 variants, and specialized forms such as CENP-A, provide highly defined reagents for mechanistic studies, structural biology, enzymatic assays, antibody validation, and assay development in chromatin and epigenetics research.

Key Features

• Species and Isoform Options: Proteins are available from human, mouse, chicken, yeast, and other species, with multiple isoforms and splice variants where applicable.
• Recombinant and Native-like Formats: Offered as bacterially expressed unmodified proteins, eukaryotic-expressed proteins carrying complex PTMs, or chemically modified proteins with precisely defined modifications.
• Tagged and Engineered Constructs: Available with His-tag, FLAG, AviTag, GFP, SNAP/CLIP tags, or engineered cysteine residues for site-specific labeling and crosslinking applications.
• Pre-Assembled Chromatin Products: Variant-containing histone octamers, mononucleosomes, nucleosome arrays, and CENP-A nucleosomes assembled on defined DNA sequences are available for advanced chromatin studies.
• Functional Validation: Quality control includes SDS-PAGE, intact mass spectrometry, variant-specific functional assays such as γ-H2A.X phosphorylation and CENP-A nucleosome assembly, as well as protein-binding analyses.

Common Applications

• Mechanistic Studies: Investigate the roles of histone variants in transcriptional regulation, DNA damage response, chromatin remodeling, and nucleosome dynamics.
• Structural Biology: Generate homogeneous samples for cryo-electron microscopy (cryo-EM), X-ray crystallography, and crosslinking mass spectrometry using variant-containing nucleosomes.
• Enzymatic Assays: Serve as substrates for chromatin readers, writers, and erasers that recognize variant-specific structural features or PTM-dependent interactions.
• Chromatin Assembly and Remodeling Assays: Evaluate the impact of variant incorporation on nucleosome stability, remodeling efficiency, and higher-order chromatin organization.
• Centromere and Kinetochore Research: Utilize CENP-A (CenH3) nucleosomes to study centromere identity, kinetochore assembly, and chromosome segregation mechanisms.
• Antibody Validation and Development: Use purified variants as reference antigens for assessing antibody specificity toward variant-specific epitopes or post-translational modifications.
• Cell Biology and Imaging: Employ GFP-tagged or epitope-tagged variants in live-cell imaging, fluorescence recovery after photobleaching (FRAP), and chromatin localization studies.