[Lys(Ac)5/8/12/16]-Histone H4 (1-21)-GGK(Biotin)

Product Name: [Lys(Ac)5/8/12/16]-Histone H4 (1-21)-GGK(Biotin)

Sequence One Letter Code: SGRG-K(Ac)-GG-K(Ac)-GLG-K(Ac)-GGA-K(Ac)-RHRKV-GGK(Biotin)

Sequence Three Letter Code: H-Ser-Gly-Arg-Gly-Lys(Ac)-Gly-Gly-Lys(Ac)-Gly-Leu-Gly-Lys(Ac)-Gly-Gly-Ala-Lys(Ac)-Arg-His-Arg-Lys-Val-Gly-Gly-Lys(Biotin)-OH

Molecular Weight: 2728.3

Purity: 95%

Form: Lyophilized

Storage Conditions: - 20 °C

Research Area: epigenetics

Source / Species: human

Conjugation: Conjugated

Conjugation Type: Biotins

Code Nacres: NA.26

Application: This peptide corresponds to histone H4 residues 1–21 and contains tetra-acetylation at lysines 5, 8, 12, and 16, a modification pattern associated with chromatin relaxation and active DNA replication. The C-terminal glycine–glycine linker followed by a biotinylated lysine enables affinity capture using streptavidin-based systems. Combinatorial acetylation of the H4 tail regulates chromatin accessibility, nucleosome dynamics, and recruitment of bromodomain-containing proteins. This peptide is valuable for studying histone acetylation cross-talk, chromatin remodeling mechanisms, and enzyme specificity. It supports biochemical and epigenetic investigations into transcriptional activation and replication-associated chromatin states.

Current Research: Histone acetylation is a key epigenetic mechanism that regulates chromatin structure, gene expression, and DNA replication. Acetylation of lysine residues on histone tails reduces electrostatic interactions between histones and DNA, promoting a more open chromatin configuration that facilitates access of regulatory proteins. Among the core histones, histone H4 contains several lysine residues within its N-terminal tail that are commonly acetylated during transcriptional activation and chromatin remodeling. The H4 (1–21) tetra-acetylated peptide, containing acetylation at lysines K5, K8, K12, and K16, reproduces a combinatorial modification pattern associated with relaxed chromatin and active replication. With the addition of a C-terminal glycine–glycine linker and a biotinylated lysine, this peptide provides a versatile tool for affinity-based assays and epigenetic studies. The Histone H4 N-Terminal Tail as a Regulatory Platform Histone H4 is one of the four core histone proteins that assemble into nucleosomes, the fundamental structural units of chromatin. Each nucleosome contains an octamer of histones around which DNA is wrapped, creating a compact yet dynamic structure that regulates access to genetic information. The N-terminal tail of histone H4, extending from the nucleosome core, is rich in lysine residues that are targets for post-translational modifications. Among these residues, lysines 5, 8, 12, and 16 are frequently acetylated in actively transcribed chromatin and during chromatin assembly following DNA replication. Because this region plays a major role in mediating interactions between nucleosomes and chromatin-associated proteins, modifications of the H4 tail can have profound effects on chromatin organization. Biological Significance of H4 Tetra-Acetylation The simultaneous acetylation of K5, K8, K12, and K16 on histone H4 represents a well-characterized modification pattern associated with chromatin relaxation and transcriptional activation. Each acetylation event neutralizes the positive charge of the lysine side chain, reducing histone–DNA interactions and weakening contacts between neighboring nucleosomes. When multiple lysine residues are acetylated simultaneously, the cumulative effect significantly alters chromatin structure. This combinatorial acetylation pattern promotes nucleosome mobility and increased chromatin accessibility, enabling transcription factors, replication machinery, and DNA repair complexes to interact with genomic DNA. Tetra-acetylated H4 tails are also frequently observed in newly synthesized histones during DNA replication and chromatin assembly, reflecting their role in replication-associated chromatin remodeling. Recruitment of Bromodomain-Containing Proteins Acetylated lysine residues serve as recognition sites for bromodomain-containing proteins, a family of chromatin readers that specifically bind acetylated histone tails. These proteins often form part of chromatin remodeling complexes or transcriptional coactivators that regulate gene expression. The presence of multiple acetylation marks on the H4 tail enhances recruitment of bromodomain-containing factors, facilitating the assembly of transcriptional regulatory complexes and chromatin remodeling machinery. Through these interactions, combinatorial histone acetylation helps coordinate chromatin accessibility with transcriptional activation. Studying peptides containing defined acetylation patterns provides insight into how reader proteins recognize specific combinations of histone modifications. Structural Design of the Biotinylated Peptide The synthetic H4 (1–21) tetra-acetylated peptide reproduces the first 21 amino acids of the histone H4 N-terminal tail with site-specific acetylation at lysines 5, 8, 12, and 16. This design faithfully mimics a biologically relevant acetylation state found in active chromatin. At the C-terminus, the peptide contains a glycine–glycine linker followed by a biotinylated lysine residue. The flexible linker separates the histone sequence from the biotin tag, ensuring that the modified histone region remains accessible for protein interactions. Biotin provides an efficient means of immobilizing the peptide on streptavidin-coated beads, plates, or biosensor surfaces, enabling a variety of affinity-based assays. Applications in Chromatin Interaction Studies Biotinylated histone peptides are commonly used in pull-down experiments to identify proteins that interact with specific histone modifications. In such assays, the peptide is immobilized through the strong biotin–streptavidin interaction and incubated with nuclear extracts or purified proteins. Proteins that recognize the tetra-acetylated H4 tail can bind to the peptide and be isolated for analysis using immunoblotting or mass spectrometry. These studies help identify chromatin-binding complexes and bromodomain-containing proteins involved in transcriptional regulation and chromatin remodeling. Investigating Histone Acetylation Cross-Talk One of the key advantages of using tetra-acetylated peptides is the ability to examine cross-talk between multiple histone acetylation sites. Combinatorial modifications can influence enzyme activity, protein binding, and chromatin structure in ways that differ from single modifications. By comparing tetra-acetylated peptides with partially acetylated or unmodified variants, researchers can investigate how specific combinations of acetylation marks influence chromatin signaling pathways. These experiments help clarify how the “histone code” operates through coordinated patterns of histone modifications. Studying Enzyme Specificity and Chromatin Remodeling The peptide also provides a useful substrate for examining enzyme specificity, particularly for histone acetyltransferases and deacetylases that regulate acetylation patterns on histone H4. In addition, it supports studies of chromatin remodeling factors that recognize acetylated histone tails. Such experiments contribute to understanding how chromatin-modifying enzymes and regulatory complexes cooperate to control transcriptional activation, replication-associated chromatin states, and epigenetic signaling networks. Conclusion The biotinylated H4 (1–21) tetra-acetylated peptide models a key combinatorial histone modification pattern associated with chromatin relaxation and active DNA replication. By incorporating acetylation at lysines 5, 8, 12, and 16 along with a biotin tag for affinity capture, the peptide provides a powerful tool for studying chromatin accessibility and histone modification signaling. Its applications include protein–histone interaction assays, chromatin remodeling studies, enzyme specificity analyses, and investigations of histone acetylation cross-talk. Through these uses, the peptide supports research into the epigenetic mechanisms that regulate transcription and genome maintenance.