Histone H3 Modification Multiplex Assay Kit (Colorimetric, Circulating)

Product details

The Histone H3 Modification Multiplex Assay Kit (Colorimetric, Circulating)(ab233495) is designed for measuring multiple Histone H3 modifications simultaneously from plasma and serum. In an assay with this kit, each Histone H3 modified at specific sites will be captured by an antibody that is coated on the strip wells and specifically targets the appropriate histone modification pattern. The captured histone modified at specific sites will be detected with a detection antibody, followed by a color development reagent. The ratio of modified histone is proportional to the intensity of absorbance measured by a microplate reader at a wavelength of 450 nm.

Up to 22 modified Histone H3 patterns can be measured simultaneously.

Histone modifications have been defined as epigenetic modifiers. Post-translational modifications of histones include the acetylation of specific lysine residues by histone acetyltransferases (HATs), deacetylation by histone deacetylases (HDACs), methylation of lysine and arginine residues by histone methytransferases (HMTs), the demethylation of lysine residues by histone demethylases (HDMTs), and the phosphorylation of specific serine groups by histone kinases (HKs). Additional histone modifications include the attachment of ubiquitin (Ub), small ubiquitin-like modifiers (SUMOs), and poly ADP-ribose (PAR) units. Next to DNA methylation, histone acetylation and histone methylation are the most well characterized epigenetic marks. Generally, tri-methylation at H3-K4, H3-K36, or H3-K79 results in an open chromatin configuration and is therefore characteristic of euchromatin. Euchromatin is also characterized by a high level of histone acetylation, which is mediated by histone acetyltransferases. Conversely, histone deacetylases have the ability to remove this epigenetic mark, which leads to transcriptional repression. Condensed heterochromatin is enriched in tri-methylation of H3-K9 and H3-K27, and silencing of euchromatin loci caused by histone deacetylation involves the recruitment of specific K9 histone methyltransferases. Methylated H3-K9 provides a binding site for the chromodomain-containing heterochromatin protein 1 (HP1), which induces transcriptional repression and heterochromatinization. At euchromatic loci, this process is mediated by co-repressors, such as retinoblastoma protein pRb or KAP1. Histone demethylases have the opposite effect on transcription. For example, the histone demethylase LSD1 is responsible for H3K4 demethylation, which leads to transcriptional inactivation. Other histone demethylases, such as jumonji (JHDM2A), are responsible for H3K9 demethylation, whereas JHDM1 has the ability to convert active chromatin marks such as H3-K36me2, to an unmodified state. Lysine residues can be mono-, di-, or trimethylated, each of which can differentially regulate chromatin structure and transcription. Along with other histone modifications such as phosphorylation, this enormous variation leads to a multiplicity of possible combinations of different modifications. This may constitute a "histone code", which can be read and interpreted by different cellular factors.

Abnormal histone modification patterns have been associated with many different diseases such as cancer, autoimmune disorders, and inflammatory and neurological diseases. Circulating modified histones in the plasma or serum are demonstrated to be and considered as the markers for many different diseases or pathological change. Therefore, detection of circulating histone H3 modifications would provide useful information for a better understanding of epigenetic regulation of gene activation and silencing, histone modification-associated pathological disease process, screening of diseaserelated biomarkers, as well as for developing histone modification-targeted drugs.