[Lys(Me3)9]-Histone H3 (1-21)-GGK(Biotin)-NH2

Product Name: [Lys(Me3)9]-Histone H3 (1-21)-GGK(Biotin)-NH2

Sequence One Letter Code: ARTKQTAR-K(Me3)-STGGKAPRKQLA-GGK(Biotin)-NH2

Sequence Three Letter Code: H-Ala-Arg-Thr-Lys-Gln-Thr-Ala-Arg-Lys(Me3)-Ser-Thr-Gly-Gly-Lys-Ala-Pro-Arg-Lys-Gln-Leu-Ala-Gly-Gly-Lys(Biotin)-NH2

Molecular Weight: 2764.4

Purity: 95%

Form: Lyophilized

Storage Conditions: - 20 °C

Research Area: epigenetics

Source / Species: human

Conjugation: Conjugated

Conjugation Type: Biotins

Code Nacres: NA.26

Application: [Lys(Me3)9]-Histone H3 (1–21)-GGK(Biotin) is a synthetic histone peptide corresponding to residues 1–21 of histone H3 with trimethylation at lysine 9 (H3K9me3) and a C-terminal GG linker followed by a biotinylated lysine. H3K9me3 is a well-known epigenetic mark associated with heterochromatin formation and transcriptional repression. This modification plays a central role in chromatin compaction, gene silencing, and maintenance of genomic stability. The incorporated biotin tag allows efficient affinity capture, pull-down assays, and detection in biochemical and proteomic studies. This peptide is widely used to investigate proteins that recognize repressive histone marks, as well as molecular mechanisms underlying epigenetic gene silencing, heterochromatin assembly, and chromatin organization.

Current Research: Epigenetic regulation of gene expression is largely controlled by chemical modifications on histone proteins, which influence chromatin structure and accessibility. Among these modifications, trimethylation of lysine 9 on histone H3 (H3K9me3) is one of the most important marks associated with transcriptional repression and heterochromatin formation. [Lys(Me3)9]-Histone H3 (1–21)-GGK(Biotin) is a synthetic histone peptide designed to replicate this specific modification while incorporating a biotin tag for experimental detection and affinity purification. Because of its structural and functional relevance, this peptide has become a valuable tool for investigating chromatin organization, epigenetic gene silencing, and protein interactions with repressive histone marks. H3K9 Trimethylation and Repressive Chromatin States Histone H3 lysine 9 trimethylation is a hallmark of heterochromatin, the tightly packed form of chromatin that limits access to DNA and suppresses transcription. This epigenetic mark is enriched in regions of the genome that must remain transcriptionally inactive, including repetitive DNA elements, pericentromeric regions, and silenced genes. The H3K9me3 modification contributes to gene repression through several mechanisms. First, it promotes chromatin compaction, creating a more condensed nucleosome structure that restricts transcription factor binding. Second, it serves as a docking site for heterochromatin-associated proteins, such as members of the HP1 (heterochromatin protein 1) family, which further stabilize the repressive chromatin environment. Through these interactions, H3K9me3 helps maintain long-term gene silencing and plays an essential role in preserving genomic integrity. Genome-wide mapping studies have shown that H3K9me3 is widely distributed in regions that require stable transcriptional repression. The modification is therefore considered a key component of epigenetic memory, ensuring that specific genes remain inactive across cell divisions. Structural Design of the Peptide The [Lys(Me3)9]-Histone H3 (1–21)-GGK(Biotin) peptide corresponds to the first 21 amino acids of the histone H3 N-terminal tail, which contains several sites commonly modified during epigenetic regulation. Within this sequence, lysine at position 9 is trimethylated, reproducing the H3K9me3 epigenetic mark found in native chromatin. In addition to the methylation modification, the peptide includes a C-terminal glycine–glycine (GG) linker followed by a lysine residue conjugated to biotin. This design provides several experimental advantages. The flexible linker helps maintain accessibility of the histone sequence for protein binding, while the biotin tag enables efficient immobilization on streptavidin-coated surfaces or affinity matrices. This combination allows researchers to use the peptide in a variety of biochemical and proteomic assays that require selective capture and detection of histone-interacting proteins. Investigating Proteins that Recognize H3K9me3 Many chromatin-associated proteins specifically recognize histone modifications through specialized domains known as epigenetic reader domains. In the case of H3K9me3, proteins such as HP1 contain chromodomains that bind selectively to the trimethylated lysine residue. These interactions are crucial for establishing and maintaining heterochromatin. The biotinylated histone peptide provides a convenient experimental platform for identifying and characterizing such interactions. By immobilizing the peptide on streptavidin-based supports, researchers can perform affinity pull-down experiments to isolate proteins that bind specifically to the H3K9me3 mark. Subsequent analysis by mass spectrometry or immunodetection can reveal components of chromatin regulatory complexes involved in gene silencing. These studies help clarify how epigenetic signals are interpreted by cellular machinery and how specific histone modifications recruit proteins that shape chromatin architecture. Applications in Chromatin and Epigenetics Research Because it faithfully mimics a repressive histone modification while offering convenient biochemical handling, [Lys(Me3)9]-Histone H3 (1–21)-GGK(Biotin) is widely used in epigenetics and chromatin biology research. The peptide supports experiments aimed at understanding the molecular mechanisms that govern heterochromatin formation and transcriptional repression. Common research applications include: Affinity capture and pull-down assays for identifying H3K9me3-binding proteins Protein–peptide interaction studies involving chromatin regulators Proteomic analyses of heterochromatin-associated complexes Investigation of epigenetic signaling pathways that control gene silencing Biochemical assays examining recognition of repressive histone marks The peptide can also be used to compare binding specificity between different histone methylation states, providing insight into how chromatin regulators distinguish between epigenetic signals. Role in Genomic Stability and Disease Research Proper regulation of H3K9 trimethylation is essential for maintaining genomic stability. By silencing repetitive sequences and transposable elements, heterochromatin prevents unwanted recombination events and protects the genome from structural instability. Alterations in H3K9me3 distribution or recognition have been implicated in several diseases, including cancer, developmental disorders, and neurodegenerative conditions. Abnormal heterochromatin organization can lead to dysregulated gene expression and chromosomal instability, both of which contribute to disease progression. Using synthetic peptides that replicate this modification allows researchers to dissect the molecular pathways involved in epigenetic repression and chromatin maintenance, offering insights into how disruptions in these processes contribute to human disease. A Valuable Tool for Studying Repressive Epigenetic Marks As the field of epigenetics continues to expand, the need for precise experimental models of histone modifications remains critical. [Lys(Me3)9]-Histone H3 (1–21)-GGK(Biotin) provides a practical and highly specific platform for studying how trimethylated H3K9 influences chromatin structure, protein recruitment, and transcriptional repression. By combining a biologically relevant histone modification with a convenient biotin affinity tag, this synthetic peptide enables detailed investigation of heterochromatin assembly, epigenetic gene silencing, and chromatin organization, helping researchers uncover the molecular principles that govern genome regulation.