[Lys(Me3)9]-Histone H3 (3-17)

Product Name: [Lys(Me3)9]-Histone H3 (3-17)

Sequence One Letter Code: TKQTAR-K(Me3)-STGGKAPR

Sequence Three Letter Code: H-Thr-Lys-Gln-Thr-Ala-Arg-Lys(Me3)-Ser-Thr-Gly-Gly-Lys-Ala-Pro-Arg-OH

Molecular Weight: 1630

Purity: 95%

Form: Lyophilized

Storage Conditions: - 20 °C

Research Area: epigenetics

Source / Species: human

Conjugation: Unconjugated

Code Nacres: NA.26

Application: This histone H3-derived peptide contains trimethylation at lysine 9 (H3K9me3), a well-known epigenetic mark associated with transcriptional repression and heterochromatin formation. H3K9 trimethylation is recognized by specific chromatin-binding proteins and plays an important role in gene silencing, genome stability, and chromatin organization. By mimicking the native histone tail with a defined methylation state, this peptide provides a useful tool for investigating histone methylation–dependent protein interactions. It is commonly used in binding assays, enzyme activity studies, and structural analyses involving histone methyltransferases, demethylases, and methyl-lysine reader domains. The peptide supports epigenetics research focused on chromatin regulation, transcriptional repression, and mechanisms underlying developmental gene regulation and disease-associated epigenetic changes.

Current Research: Introduction to Histone Methylation and Epigenetic Regulation Epigenetic modifications of histone proteins play a central role in regulating gene expression and chromatin structure. Among these modifications, lysine methylation on histone tails is one of the most extensively studied mechanisms controlling transcriptional activity and genome organization. Specific methylation patterns on histones act as molecular signals that recruit regulatory proteins, thereby influencing chromatin accessibility and transcriptional states. One of the most important epigenetic marks is trimethylation of lysine 9 on histone H3 (H3K9me3). This modification is strongly associated with transcriptional repression and heterochromatin formation, making it a key regulatory signal in gene silencing and genome stability. Synthetic peptides representing histone H3 sequences containing this modification provide valuable tools for studying epigenetic regulation and chromatin-associated protein interactions. Structural Features of the H3K9me3 Peptide The H3K9me3 peptide is derived from the N-terminal tail of histone H3 and includes trimethylation at lysine 9, reproducing the modification found in native chromatin. Histone tails extend outward from the nucleosome core and are highly accessible for enzymatic modification and protein recognition. Trimethylation at lysine 9 alters the chemical and structural properties of the histone tail, creating a specific binding site for methyl-lysine recognition domains found in many chromatin-associated proteins. These interactions are essential for establishing and maintaining transcriptionally silent chromatin regions. By incorporating a defined methylation state, the peptide accurately mimics the native epigenetic signal and enables detailed investigation of methylation-dependent molecular interactions. Biological Role of H3K9 Trimethylation H3K9 trimethylation is widely recognized as a hallmark of heterochromatin, the tightly packed form of chromatin associated with transcriptional repression. This epigenetic mark contributes to the formation of stable chromatin domains that limit access of transcriptional machinery to specific genomic regions. Proteins that recognize H3K9me3 often contain chromodomains, Tudor domains, or other methyl-lysine binding modules. These proteins bind selectively to the methylated histone tail and recruit additional factors that promote chromatin compaction and gene silencing. Through these interactions, H3K9me3 plays an essential role in regulating gene expression patterns, maintaining genome stability, and controlling developmental gene programs. Dysregulation of this modification has been linked to multiple diseases, including cancer and developmental disorders. Applications in Protein–Peptide Binding Assays Synthetic H3K9me3 peptides are widely used in protein–peptide interaction studies designed to identify and characterize proteins that recognize methylated histone residues. In these experiments, the peptide serves as a model substrate that allows researchers to evaluate how specific chromatin-binding proteins interact with the methylated histone tail. Binding assays using the peptide can reveal the affinity, specificity, and structural requirements of methyl-lysine recognition domains. These studies are essential for understanding how chromatin-binding proteins interpret epigenetic signals and regulate gene expression. Such assays are often used to characterize interactions involving heterochromatin protein complexes and other regulatory factors involved in chromatin organization. Studying Histone-Modifying Enzymes In addition to binding studies, the H3K9me3 peptide is also used in experiments examining histone-modifying enzymes, including histone methyltransferases and demethylases. These enzymes dynamically regulate histone methylation states, thereby influencing chromatin structure and transcriptional activity. Using a peptide substrate with a defined methylation mark allows researchers to investigate how enzymes recognize modified histone tails and how enzymatic activity contributes to epigenetic regulation. Such studies help clarify the mechanisms by which histone methylation patterns are established, maintained, or reversed. Structural and Mechanistic Investigations The H3K9me3 peptide also supports structural biology studies focused on understanding how proteins interact with methylated histone residues at the molecular level. Techniques such as crystallography, nuclear magnetic resonance, and other structural approaches can be used to analyze peptide–protein complexes. These structural insights help reveal how recognition domains selectively bind methylated lysine residues and how these interactions influence chromatin architecture. Understanding these mechanisms is essential for deciphering the molecular language of epigenetic regulation. Relevance to Epigenetics and Disease Research Because H3K9me3 is a key epigenetic mark involved in gene silencing, the peptide is widely used in epigenetics research exploring chromatin regulation and transcriptional control. It enables researchers to investigate how chromatin-binding proteins interpret histone methylation signals and how these signals influence genome organization. Alterations in histone methylation patterns are associated with a variety of diseases, including cancer and developmental disorders. Studying H3K9me3 interactions helps researchers understand how epigenetic changes contribute to disease progression and may reveal potential targets for therapeutic intervention. Conclusion The H3K9me3 histone H3 peptide is a valuable research tool that mimics the trimethylated lysine 9 modification found in native chromatin. By reproducing this important epigenetic mark, the peptide enables detailed analysis of histone methylation–dependent protein interactions. Widely used in binding assays, enzymatic studies, and structural investigations, the H3K9me3 peptide supports research exploring chromatin regulation, transcriptional repression, and epigenetic signaling. Through these applications, it continues to contribute to a deeper understanding of gene regulation mechanisms and disease-associated epigenetic alterations.