[Lys(Ac)9]-Histone H3 (1-24)

Product Name: [Lys(Ac)9]-Histone H3 (1-24)

Sequence One Letter Code: ARTKQTAR-K(Ac)-STGGKAPRKQLATKA

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

Chemical Formula:C109H198N40O33

Molecular Weight: 2597.2

Purity: 95%

Form: Lyophilized

Storage Conditions: - 20 °C

Research Area: epigenetics

Source / Species: human

Conjugation: Unconjugated

Code Nacres: NA.26

Application: [Lys(Ac)9]-Histone H3 (1–24) is a synthetic histone peptide acetylated at lysine 9, a modification commonly associated with transcriptionally active chromatin and gene activation. H3K9 acetylation promotes open chromatin structure and facilitates recruitment of transcriptional machinery. Increased levels of this modification have been linked to upregulation of genes involved in DNA repair and therapy resistance, including MGMT in glioblastoma models. This peptide provides a useful tool for studying histone acetylation–mediated regulation of gene expression, chromatin remodeling, and histone acetyltransferase activity. It is frequently used in epigenetics research investigating transcriptional regulation, chromatin accessibility, and the role of histone acetylation in cancer progression and therapeutic response.

Current Research: Histone modifications play a fundamental role in regulating chromatin structure and gene expression. Among these modifications, acetylation of lysine residues on histone H3 is closely associated with transcriptional activation and open chromatin states. [Lys(Ac)9]-Histone H3 (1–24) is a synthetic peptide representing the N-terminal region of histone H3 with acetylation at lysine 9 (H3K9ac), a well-characterized epigenetic mark linked to active gene transcription. Because of its importance in chromatin biology and transcriptional regulation, this peptide has become a valuable experimental reagent for studying histone acetylation, chromatin remodeling, and epigenetic signaling pathways. Histone Acetylation and Chromatin Accessibility Histone proteins form the core of nucleosomes, around which DNA is wrapped to create chromatin. The N-terminal tails of histones are subject to various post-translational modifications, including acetylation, methylation, phosphorylation, and ubiquitination. These modifications influence how tightly DNA is packaged and how accessible it is to transcription factors and regulatory proteins. Acetylation of lysine residues, such as H3K9 acetylation, neutralizes the positive charge on lysine side chains. This reduces the electrostatic interaction between histones and negatively charged DNA, leading to a more relaxed chromatin structure. As chromatin becomes more open, transcription factors and RNA polymerase gain easier access to promoter regions, facilitating gene transcription. H3K9 acetylation is therefore widely recognized as a hallmark of transcriptionally active chromatin and is frequently enriched near gene promoters and regulatory regions associated with active gene expression. Structural Design of [Lys(Ac)9]-Histone H3 (1–24) The [Lys(Ac)9]-Histone H3 (1–24) peptide corresponds to the first 24 amino acids of the histone H3 N-terminal tail. This region contains multiple regulatory lysine residues that are targets of epigenetic modifications. In this synthetic peptide, lysine at position 9 is acetylated, faithfully reproducing the H3K9ac modification found in vivo. By isolating this modification within a defined peptide sequence, researchers can investigate how H3K9 acetylation affects protein recognition, chromatin interactions, and transcriptional regulation. Synthetic histone peptides offer several advantages in experimental systems. They allow researchers to examine the effects of a single, well-defined modification without interference from additional histone marks or chromatin components. This controlled design makes them particularly useful for biochemical assays and studies of histone-binding proteins. Recruitment of Transcriptional Machinery One of the primary functions of histone acetylation is to facilitate recruitment of transcriptional regulators and chromatin-modifying complexes. Proteins containing bromodomains, for example, recognize acetylated lysine residues and bind selectively to acetylated histones. These interactions help recruit transcriptional coactivators, chromatin remodelers, and RNA polymerase complexes to gene promoters. As a result, H3K9 acetylation acts as a signaling mark that promotes transcriptional activation and gene expression. In many biological systems, the presence of H3K9ac correlates strongly with genes that are actively transcribed or poised for activation. Role in DNA Repair and Cancer Biology Histone acetylation also plays a role in cellular responses to DNA damage and therapeutic stress. Increased levels of H3K9 acetylation have been associated with enhanced expression of genes involved in DNA repair pathways. One example involves the gene MGMT (O6-methylguanine-DNA methyltransferase), which is responsible for repairing DNA damage caused by alkylating agents. In certain glioblastoma models, elevated H3K9 acetylation at the MGMT promoter region has been linked to increased MGMT expression and resistance to chemotherapy. These observations highlight the broader role of histone acetylation in regulating gene networks that influence cancer progression, therapeutic resistance, and cellular stress responses. Applications in Epigenetics and Chromatin Research Because it reproduces a biologically relevant histone modification, [Lys(Ac)9]-Histone H3 (1–24) is widely used in epigenetics and chromatin biology research. The peptide allows scientists to examine how H3K9 acetylation influences protein binding, transcriptional regulation, and chromatin dynamics. Typical experimental applications include: Protein–peptide interaction studies involving bromodomain-containing proteins Histone acetyltransferase (HAT) activity assays Chromatin-binding protein characterization Biochemical assays studying histone modification recognition Investigation of transcriptional regulation mechanisms Researchers often use modified histone peptides as substrates or probes in assays designed to understand how histone modifications regulate gene expression. Insights into Epigenetic Regulation Epigenetic marks such as H3K9 acetylation help coordinate complex gene expression programs during development, differentiation, and cellular adaptation. Changes in histone acetylation patterns can rapidly alter chromatin accessibility, enabling cells to respond to environmental signals and physiological demands. At the same time, dysregulation of histone acetylation has been implicated in a variety of diseases, particularly cancer. Abnormal acetylation patterns can lead to inappropriate gene activation or silencing, contributing to tumor progression and altered cellular behavior. A Valuable Tool for Studying Histone Acetylation Synthetic peptides that reproduce specific histone modifications provide powerful experimental systems for dissecting epigenetic mechanisms. By faithfully mimicking the H3K9 acetylation mark, [Lys(Ac)9]-Histone H3 (1–24) enables researchers to study how histone acetylation regulates chromatin structure, transcriptional activation, and gene expression. Through applications in biochemical assays, chromatin studies, and epigenetic research, this peptide supports investigations into the molecular processes that control chromatin accessibility, transcriptional regulation, and the role of histone acetylation in disease and therapeutic response.