DNA methylation is one of the central epigenetic modifications in the genome of higher eukaryotes, and involves the transferring of a methyl group from S-adenosyl-L-methionine (SAM) to the C5 position of cytosine, mostly within CpG dinucleotides. The establishment and maintenance of DNA methylation patterns are associated with DNA methyltransferases, mainly including DNMT1, DNMT3a, and DNMT3b, where DNMT1 is the most abundant DNMT in mammalian cells and acts as the primary maintenance methyltransferase to keep the methylation of DNA that is already established at the genome. DNMT3a and DNMT3b are capable of adding de novo CpG methylation marks and thus may dynamically regulate gene silencing, which is important for embryonic development in epigenetic transcriptional regulation. Two additional enzymes, DNMT2 and DNMT3L, may also have more specialized but related functions. DNMT2 could methylate tRNAAsp at C38 and DNMT3L as a catalytically inactive regulatory factor of DNMTs is essential for the function of DNMT3A and DNMT3B. DNA methylation is of great importance in modulating chromatin structure, thus controlling X-chromosome inactivation, genomic imprinting and gene expression.

Figure 1. The reaction mechanism of the methylation of cytosine. (Poh, W. J.; et al. 2016)

An ever-increasing body of evidence has indicated many types of genetic disorders and a large number of human malignancies are closely related with abnormal DNA methylation due to the increase in the expression or activity of DNMTs. DNMTs inhibition may result in demethylation and expression of silenced genes. DNMT is a potentially predictive biomarker and therapeutic target in the diagnosis and treatment of various cancers, and DNMT inhibitors could therefore have potential applications in future oncology drug development.

Creative BioMart is at the forefront of epigenetic drug discovery and aims at solving challenges by offering a panel of DNA methyltransferase screening assays for DNMT inhibitors screening and profiling. Creative BioMart offers DNMTs screening services, including DNMT1, DNMT3a and DNMT3b, by utilizing chemiluminescent or colorimetrical method. The core platform technologies and skilled work team at Creative BioMart make it available for our clients to develop an impressive early discovery pipeline focused on the DNMT class of targets. Trust us to promote you DNMTs-based lead optimization with the most competitive price and highest data quality in a short timeline. Creative BioMart produces all the DNMTs and substrates present in the assay, which are also commercially available for other academic or CRO institution.

Procedure of DNA Methyltransferase Screening at Creative BioMart

a. Chemiluminescent Method

Highly specific antibodies that recognize methyl groups are employed in this protocol. SAM is first incubated with a sample containing assay buffer and purified recombinant DNMT. Acceptor beads, a primary antibody, and donor beads are subsequently added. The ultimate step is to read the Alpha-counts.

Figure 2. General procedure of chemiluminescent method for DNMT screening assay

b. Colorimetrical Method

Frist, the unique cytosine-rich DNA substrate is stably coated on the strip wells that have been specifically treated to have a high DNA absorption ability. DNMT and inhibitor are then incubated with substrates to transfer a methyl group from Adomet to cytosine of DNA. Two kinds of antibody are applied sequentially to capture and recognize the methylated DNA. The ratio or amount of methylated DNA is proportional to enzyme activity and can then be colorimetrically quantified through an ELISA-like reaction.

Figure 3. Schematic procedure of colorimetrical method for DNMT screening assay

Features of DNA Methyltransferase Screening Services at Creative BioMart

1. Simple, reliable, and consistent assay conditions
2. Rapid procedure that is completed within a few hours
3. Pioneering colorimetric assay without extraction and chromatography
4. Flexible: manual or high throughput analysis due to the strip microplate format

A broad range of services at Creative BioMart make it easy to screen and profile your compounds against target DNMTs. Our cutting-edge science team is dedicated to ensuring that our DNMTs profiling services are implemented at the highest level of quality. We are confident to provide high-efficiency service to meet your strict project timelines on the basis of the commitment of prompt communication and on-time reporting. If you have any additional requirements in DNA Methyltransferase screening, please feel free to contact us.

References
1. Gros, C.; et al. Development of a universal radioactive DNA methyltransferase inhibition test for high-throughput screening and mechanistic studies. Nucleic Acids Res. 2013, 41(19): e185.
2. Poh, W. J.; et al. DNA methyltransferase activity assays: advances and challenges. Theranostics. 2016, 6(3): 369-391.