[Cit3]-Histone H4 (1-23)-GGK(Biotin)

Product Name: [Cit3]-Histone H4 (1-23)-GGK(Biotin)

Sequence One Letter Code: SG-Cit-GKGGKGLGKGGAKRHRKVLR-GGK(Biotin)

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

Molecular Weight: 2830.5

Purity: 95%

Form: Lyophilized

Storage Conditions: - 20 °C

Research Area: epigenetics

Source / Species: human

Conjugation: Conjugated

Conjugation Type: Biotins

Code Nacres: NA.26

Application: Histone H4 (1–23) R3Cit-GGK(Biotin) is a synthetic peptide corresponding to the N-terminal tail of histone H4 with citrullination at arginine 3 and a C-terminal GGK-biotin linker. Citrullination, also known as deimination, is catalyzed by peptidylarginine deiminase 4 (PADI4) and converts arginine to citrulline, altering charge properties and influencing chromatin structure. Modification at H4R3 can inhibit arginine methylation and has been associated with repression of nuclear hormone receptor-dependent transcription. The incorporated biotin tag allows efficient use in affinity-based assays, including pull-down experiments and interaction studies. This peptide is widely used as a research tool for investigating histone citrullination, epigenetic modification cross-talk, and the regulatory roles of PADI enzymes in chromatin organization and transcriptional control.

Current Research: Post-translational modifications (PTMs) of histone proteins are central to the regulation of chromatin structure and gene expression. Among the diverse histone modifications that influence epigenetic signaling, citrullination—also known as deimination—has gained increasing attention for its role in chromatin remodeling and transcriptional control. Synthetic peptides that mimic these modified histone regions provide valuable tools for studying the molecular mechanisms underlying epigenetic regulation. Histone H4 (1–23) R3Cit-GGK(Biotin) is a synthetic peptide representing the N-terminal tail of histone H4 with citrullination at arginine 3 (H4R3Cit) and a C-terminal GGK linker carrying a biotin tag. This design allows researchers to investigate how citrullination affects histone recognition, chromatin organization, and protein interactions involved in gene regulation. The Role of the Histone H4 N-Terminal Tail in Chromatin Histone H4 is one of the four core histone proteins that form nucleosomes, the fundamental units of chromatin. Within nucleosomes, approximately 147 base pairs of DNA are wrapped around an octamer of histone proteins composed of H2A, H2B, H3, and H4. The N-terminal tails of histones, including that of histone H4, extend outward from the nucleosome core and are accessible to chromatin-modifying enzymes and regulatory proteins. The first 20–25 amino acids of histone H4 contain several residues that undergo post-translational modifications such as acetylation, methylation, phosphorylation, and citrullination. These modifications influence chromatin structure by altering histone–DNA interactions and by recruiting specific chromatin-associated proteins. Because the H4 N-terminal region is highly involved in regulatory signaling, synthetic peptides derived from this sequence are widely used in epigenetics research to examine histone modification pathways and protein recognition mechanisms. Citrullination of Histone H4 at Arginine 3 Citrullination is a biochemical process in which the amino acid arginine is converted into citrulline. This reaction is catalyzed by the enzyme family known as peptidylarginine deiminases (PADIs), with PADI4 being a key nuclear enzyme responsible for modifying histones. During citrullination, the positively charged guanidinium group of arginine is converted into a neutral ureido group. This change significantly alters the charge properties and hydrogen bonding potential of the residue, which can affect chromatin structure and protein binding. The modification of histone H4 at arginine 3 (H4R3) has important regulatory implications. Citrullination at this site can antagonize arginine methylation, a modification typically associated with transcriptional activation. By preventing methylation, citrullination introduces a form of epigenetic cross-talk, where one modification influences the occurrence or recognition of another. Studies have also linked H4R3 citrullination to repression of nuclear hormone receptor-dependent transcription, suggesting that this modification can play a role in regulating hormone-responsive gene expression. These findings highlight the importance of citrullination as a dynamic component of the histone modification landscape. Design of the R3Cit-GGK(Biotin) Peptide The Histone H4 (1–23) R3Cit-GGK(Biotin) peptide is engineered to replicate the biologically relevant N-terminal region of histone H4 while incorporating functional features that facilitate experimental use. Key structural elements include: Residues 1–23 of histone H4, representing the regulatory N-terminal tail Citrullination at arginine 3, mimicking the naturally occurring H4R3Cit modification A C-terminal GGK linker, providing spatial separation between the peptide and affinity tag Biotin attached to the lysine residue, enabling affinity capture through streptavidin binding The GGK linker helps maintain the structural integrity of the histone sequence while ensuring that the biotin tag does not interfere with protein recognition events. Advantages of Biotinylated Histone Peptides Biotinylation is widely used in molecular biology because of its exceptionally strong interaction with streptavidin and avidin proteins. This interaction allows peptides to be immobilized efficiently on various assay platforms. For histone peptides, biotinylation provides several experimental advantages: Pull-down assays to isolate histone-binding proteins Affinity purification of chromatin-associated complexes Immobilization on streptavidin-coated beads or surfaces Compatibility with proteomics workflows, including mass spectrometry These capabilities make biotinylated peptides particularly useful for identifying proteins that recognize specific histone modifications. Applications in Epigenetics and Chromatin Research The Histone H4 (1–23) R3Cit-GGK(Biotin) peptide is commonly used in studies examining the biological functions of histone citrullination and its interaction with other epigenetic marks. Key research applications include: Protein interaction mapping Researchers use the peptide to identify proteins that recognize or respond to citrullinated histone residues. Studies of epigenetic cross-talk The peptide allows investigation of how citrullination influences other modifications such as arginine methylation. PADI enzyme research The peptide can be used to examine the activity and substrate recognition of peptidylarginine deiminase enzymes. Chromatin remodeling investigations Understanding how citrullinated histone tails interact with chromatin regulators helps reveal mechanisms that control chromatin accessibility. Transcriptional regulation studies By analyzing proteins that bind to citrullinated histone tails, researchers can better understand how these modifications influence gene expression. Supporting Research on Epigenetic Modification Networks Epigenetic regulation involves a complex network of histone modifications that interact to control chromatin structure and gene activity. Synthetic peptides that mimic specific histone modification states provide a powerful platform for dissecting these mechanisms. The Histone H4 (1–23) R3Cit-GGK(Biotin) peptide combines a biologically significant modification with a robust affinity tag, enabling efficient analysis of histone–protein interactions. Through applications in pull-down assays, interaction studies, and chromatin signaling research, this peptide supports ongoing investigations into how histone citrullination contributes to epigenetic regulation, chromatin organization, and transcriptional control.