[Lys(Me2)4]-Histone H3 (1-21)

Product Name: [Lys(Me2)4]-Histone H3 (1-21)

Sequence One Letter Code: ART-K(Me2)-QTARKSTGGKAPRKQLA

Sequence Three Letter Code: H-Ala-Arg-Thr-Lys(Me2)-Gln-Thr-Ala-Arg-Lys-Ser-Thr-Gly-Gly-Lys-Ala-Pro-Arg-Lys-Gln-Leu-Ala-OH

Chemical Formula:C96H176N36O28

Molecular Weight: 2282.8

Purity: 95%

Form: Lyophilized

Storage Conditions: - 20 °C

Research Area: epigenetics

Source / Species: human

Conjugation: Unconjugated

Code Nacres: NA.26

Application: This peptide corresponds to histone H3 residues 1–21 and is dimethylated at lysine 4 (H3K4me2), a modification enriched near transcription start sites of actively transcribed genes. H3K4 dimethylation is associated with transcriptional competence and regulatory gene expression programs. It has also been implicated in immune-related gene activation, particularly in T-cell–associated transcriptional networks. The peptide is suitable for studying histone methyltransferase activity, methyl-lysine reader interactions, and chromatin state regulation. It serves as a defined biochemical tool for investigating epigenetic mechanisms governing transcriptional control.

Current Research: Epigenetic regulation of gene expression is mediated by chemical modifications of histone proteins that influence chromatin accessibility and transcriptional activity. Among these modifications, methylation of lysine 4 on histone H3 (H3K4) plays a central role in marking transcriptionally active chromatin. Different methylation states at this residue—mono-, di-, and trimethylation—are associated with distinct genomic contexts and regulatory functions. The H3 (1–21) peptide containing dimethylation at lysine 4 (H3K4me2) provides a defined model substrate for studying how this modification contributes to transcriptional competence and chromatin signaling. Histone H3 and the Epigenetic Landscape Histone H3 is one of the core histone proteins that form nucleosomes, the structural units that organize DNA into chromatin. Within the nucleosome, DNA wraps around a histone octamer composed of two molecules each of histones H2A, H2B, H3, and H4. The N-terminal tail of histone H3 extends outward from the nucleosome surface and contains multiple lysine residues that are subject to regulatory modifications. These modifications—including acetylation, methylation, phosphorylation, and ubiquitination—serve as signals that influence chromatin structure and recruit regulatory proteins. The combination of modifications present on histone tails contributes to the epigenetic state of chromatin, determining whether genes are actively transcribed or maintained in a repressed configuration. The peptide corresponding to residues 1–21 of histone H3 contains lysine 4, a critical residue involved in regulating gene expression. Functional Significance of H3K4 Dimethylation Dimethylation of lysine 4 on histone H3 (H3K4me2) is commonly enriched near transcription start sites (TSSs) of actively transcribed or transcriptionally competent genes. Although trimethylation at this residue is often considered the most prominent marker of active promoters, the dimethylated form also plays an important role in establishing and maintaining transcriptionally permissive chromatin states. H3K4me2 is frequently observed in regions adjacent to promoters and regulatory elements where transcription factors and chromatin-modifying complexes assemble. This modification contributes to the formation of chromatin environments that support regulated gene activation. Unlike acetylation, methylation does not change the charge of lysine residues. Instead, it creates specific binding surfaces that can be recognized by methyl-lysine reader proteins, which recruit additional regulatory complexes to chromatin. Role in Gene Regulation Programs The presence of H3K4me2 at promoter regions reflects a chromatin state associated with transcriptional competence, meaning that genes are accessible for activation when appropriate regulatory signals are present. This modification can participate in establishing gene expression programs during cellular differentiation and development. In addition to its general role in transcriptional regulation, H3K4 dimethylation has been implicated in immune-related gene activation, particularly within T cells. During immune responses, changes in histone modification patterns can enable rapid activation of genes involved in cytokine production, signaling pathways, and immune cell differentiation. Because histone methylation patterns can persist through cell divisions, H3K4me2 may also contribute to epigenetic memory that helps maintain lineage-specific gene expression profiles. Studying Histone Methyltransferase Activity Histone methylation at lysine 4 is catalyzed by histone methyltransferases (HMTs) that transfer methyl groups from S-adenosylmethionine (SAM) to lysine residues. Different methyltransferase complexes are responsible for establishing mono-, di-, and trimethylation states at H3K4. The H3 (1–21) K4me2 peptide provides a useful substrate for examining histone methyltransferase activity and specificity. By using defined peptides in enzymatic assays, researchers can investigate how enzymes recognize histone sequences and regulate methylation patterns. These studies help clarify how methylation marks are established and maintained within chromatin. Investigating Methyl-Lysine Reader Proteins A major function of histone methylation is to recruit proteins that recognize specific methylation states. Domains such as PHD fingers, chromodomains, and Tudor domains can selectively bind methylated lysine residues, allowing regulatory complexes to localize to particular chromatin regions. The H3K4me2 peptide provides a defined ligand for analyzing interactions between histone modifications and methyl-lysine reader proteins. These interaction studies help identify proteins that interpret epigenetic signals and regulate transcriptional activity. Understanding these interactions is essential for deciphering the molecular mechanisms that connect histone modifications with gene regulation. Applications in Chromatin State Analysis Synthetic histone peptides are frequently used in biochemical and structural studies aimed at understanding chromatin state regulation. By isolating a specific histone modification in a defined sequence context, researchers can examine how that modification influences protein binding, enzymatic activity, and chromatin signaling pathways. The H3 (1–21) K4me2 peptide enables experiments focused on promoter-associated chromatin states, allowing investigators to analyze how histone methylation contributes to transcriptional activation and regulatory network formation. Conclusion The H3 (1–21) peptide containing dimethylated lysine 4 (H3K4me2) serves as a valuable biochemical reagent for studying promoter-associated histone methylation and transcriptional regulation. By reproducing a key epigenetic modification found near transcription start sites, the peptide supports research into histone methyltransferase activity, methyl-lysine reader recognition, and chromatin state dynamics. Through applications in binding assays, enzyme characterization, and epigenetic signaling studies, this peptide contributes to a deeper understanding of the molecular mechanisms that govern gene expression and immune-related transcriptional programs.