BellBrook Labs offers two methyltransferase assay kits that monitor the product (S-adenosyl homocysteine or SAH) of methyltransferase reactions. Their universal nature allows both assays to be used with a variety of methyltransferases including protein, DNA, and RNA as well as substrates such as histones, peptides, and nucleosomes.

The Transcreener® EPIGEN SAH Methyltransferase Assay uses a coupling enzyme that converts SAH to AMP, and is then detected by the Transcreener AMP²/GMP² Assay with an FP readout. BellBrook’s new AptaFluor® SAH Methyltransferase Assay employs a split aptamer for direct detection of SAH resulting in a positive TR-FRET signal. As workhorse for HTS, the EPIGEN assay can be used with higher SAM concentrations. The AptaFluor assay has subnanomolar sensitivity, perfect for low turnover methyltransferases that cannot be monitored by any other biochemical assay.

New AptaFluor SAH Methyltransferase Assay

The AptaFluor SAH Assay uses a naturally occurring aptamer, or riboswitch, that selectively binds with SAH, the invariant product of methyltransferase reactions. The exquisite affinity and selectivity of the riboswitch combined with a positive TR-FRET signal enable screening and profiling of histone methyltransferases with unparalleled sensitivity.

Transcreener EPIGEN SAH Methyltransferase Assay

The Transcreener EPIGEN SAH Assay provides universal methyltransferase detection in an HTS-proven format. It combines the extensively validated Transcreener AMP²/GMP² Assay with coupling enzymes that convert the SAH produced in a Methyltransferase reaction to AMP for detection with a fluorescent polarization (FP) readout.

Comparing BellBrook's Methyltransferase Assay Kits

EPIGEN AptaFluor
SAM Concentration Range
1 µM – 50 µM 100 nM – 5 µM
Lower Limit of Detection
Minimum SAH concentration generating a Z’ > 0
117.2 nM 0.6 nM
Readout FP TR-FRET
SAH Detection Method Coupled Assay Direct
HTS Compatible Yes¹ Yes¹
96, 384 & 1536 Well Compatible Yes Yes
Continuous / Kinetic Mode Yes Yes²
Universal Assay Method Yes Yes
Reagent Stability  24 hours  24 hours
Signal Stability  24 hours  24 hours

¹Compound interference of 1.3% with AptaFluor and 0.8% with EPIGEN assays detected in sample libraries tested.

²Continuous mode can only be used when using a peptide as a substrate.

Related Resources

Methyltransferase Overview

Methyltransferases are a diverse family of enzymes that catalyze the transfer of a methyl group from S-adenosylmethionine (SAM or AdoMet), the second most common enzymatic cofactor after ATP, to amino, thiol, or hydroxyl groups of acceptor molecules generating S-adenosylhomocysteine (SAH) as a byproduct.  Example acceptor substrates include endogenous and xenobiotic small molecules, proteins, DNA and RNA, and lipids.  Methyltransferases play a role in epigenetic regulation through methylation of histones at lysine and arginine residues and methylation of DNA at cytosines in hemi-methylated CpG sites. There are over 50 Protein Lysine Methyltransferases (PKMTs) in humans, at least 10 Protein Arginine Methyltransferases (PRMTs), and three DNA Methyltransferases (DNMTs). Together these enzymes play a critical role in the dynamic modification of chromatin, and they are increasingly being targeted for cancer and other diseases with an epigenetic component.

Assay Methods

Methyltransferase Assay methods rely on either detection of the methylated product or detection of SAH. There are several formats and readout options for both detection methods (Figure 1).

Detection of SAH

Assay methods that detect SAH formation have the advantage of providing universal detection of MT enzymes regardless of the acceptor substrate or the mix of methylated reaction products.  Universal assay methods reduce drug candidate assay development costs by using one single set of assay reagents for all methyltransferase targets.

Direct Detection

The new AptaFluor SAH Methyltransferase assay allows for direct detection of SAH using an aptamer. By strategically splitting aptamer, excellent assay sensitivity can be achieved. It also allows for direct detection with a positive TR-FRET readout. Direct immunodetection of SAH would also be advantageous as it would eliminate the potential for compound interference from coupling enzymes, however, it requires an antibody that specifically binds SAH in the presence of excess SAM; ie, that differentiates on the basis of a single methyl group.  There is one literature report of an FP-based methyltransferase assay using an anti-SAH antibody from a diagnostic assay kit for homocysteine, but its commercial availability is unknown.

Coupled Assays

Coupled enzyme assays have also been developed for SAH detection. For instance, SAH can be converted to homocysteine and adenosine using SAH hydrolase, and homocysteine is then detected using covalent reaction with a thiol-sensitive fluor. Alternatively, the adenine portion of SAH can be converted to urate by the sequential action of three coupling enzymes, with co-production of hydrogen peroxide in the final step. Hydrogen peroxide can be detected colorimetrically or fluorescently, via formation of resorufin. In addition, a luciferase-based coupled assay relies on the sequential conversion of SAH to adenine, AMP, and ATP, with the final step catalyzed by pyruvate phosphate dikinase. BellBrook Labs’ EPIGEN SAH Assay utilizes two coupling enzymes to convert the SAH to AMP, which can then be measured with a monoclonal antibody and tracer with negligible cross-reactivity with SAM.  This assay format can detect both histone methyltransferases and DNA methyltransferases.

Methyltransferase Assays Table

Detection TypeDetection MethodReadoutReference
SAH DetectionCompetitive FP ImmunoassayFPRef # 1
SAH DetectionCoupled Assay
(SAH to AMP)
FPRef # 2
SAH DetectionCoupled Assay
(SAH to Homocysteine (Hcy))
Ref # 3
SAH DetectionCoupled Assay
(SAHto H2O2)
FI / Colorimetric
Ref # 4
SAH DetectionCoupled Assay
(SAH to ATP)
Ref # 5
Methylated ProductFlashplate, Filter-Based Assay
(Me-histone, Me-DNA)
RadioactiveRef # 6, Ref # 7
Methylated ProductImmunoassay; Ab/ELISA
FI / ColorimetricN/A
Methylated ProductImmunoassay; Ab/ELISA, etc.
FI / TR-FRET, etc.Ref # 8, Ref # 9
Methylated ProductRestriction Enzyme Protection Assay
FI / Chemiluminescence
Ref # 10, Ref # 11

Detection of Methylated Products

The most quantitative and reliable assay method are filter-based or flash plate-based radioassays that use 3H-SAM to generate 3H-methylated products.  However, the associated regulatory and disposal costs are a liability for High Throughput Screening (HTS).  Immunoassays for methylated lysine, arginine and cytosine have been used for both PKMT and DNMT enzyme assays, either in an ELISA format or in a homogenous format such as TR-FRET.  Antibody selectivity is critical for this approach and can limit the utility of the assay, as some histone methyltransferases can generate both mono- and di-methylated lysine products, and the known antibodies do not recognize both forms.  Assays based on enzymatic cleavage (or protection) of products have also been applied to both PKMTs and DNMTs utilizing methylation state–dependent restriction enzymes or endoproteinase Lys C, which is unable to cleave at methylated lysine residues.  Although application of this approach has generally relied on a solid phase method such as ELISA, or a separation step, a more HTS-friendly fluorescence de-quenching configuration was recently developed for DNMT1.


S-Adenosylmethionine: Jack of All Trades and Master of Everything?, W.A.M. Loenen. (Journal Abstract), Department of Toxicogenetics, Division 5, Leiden University Medical Centre, Building 2, T-03-011, Einthovenweg, Leiden, The Netherlands. This email address is being protected from spambots. You need JavaScript enabled to view it.. Biochem Soc Trans. 2006 Apr;34(Pt 2):330-03.(PubMed Abstract). SUMMARY: Mini-review of the many roles and biochemical pathways of SAM and their potential impacts on human disease. SAM is the most frequent methyl donor for enzymatic methylation reactions of proteins, xenobiotic drugs, nucleic acids, and oligosaccharides known to regulate important cellular events including meiosis, biosynthesis, development, signal transduction, chromatin remodeling and gene silencing.

Epigenetics, an Emerging Target Class for Drug Screening. Comley J, Drug Discovery World, Spring, 2011.

SUMMARY: Survey of pharma and biotech epigenetics lead discovery programs.  Discussion of the emerging tools to support epigenetic screening of histone deacetylases, histone methyltransferases, DNA methyltransferases, histone demethylases, and histone acetyltransferases.

Chromatin Modifications and Their Function.  Kouzarides T, Cell 2007; 128:693-705.

SUMMARY:  Modifications on nucleosomes can either disrupt chromatin contacts or change the recruitment of nonhistone proteins to chromatin thereby dictating the higher-order chromatin structure and orchestrating the ordered recruitment of enzyme complexes influencing many fundamental biological processes, some of which may be epigenetically inherited.

DNA Methyltransferases as Targets for Cancer Therapy.  Ghoshal K, Bai S, Drugs Today (Barc) 2007; 43:395-422.

SUMMARY:  A review including the recent advances of the molecular mechanisms of action and clinical results for inhibitors of DNA methyltransferases.

Protein Methyltransferases as a Target Class for Drug Discovery.  Copeland RA, Solomon ME, Richon VM, Nat Rev Drug Discov 2009; 8:724-732.

SUMMARY: Review the biological, biochemical and structural information presenting protein methyltransferases as a novel, chemically tractable target class for drug discovery.

Biological Rationale for the Use of DNA Methyltransferase Inhibitors as New Strategy for Modulation of Tumor Response to Chemotherapy and Radiation.  Gravina GL, Festuccia C, Marampon F, Popov VM, Pestell RG, Zani BM, Tombolini V, Mol Cancer 2010 Nov 25; 9:305.

SUMMARY:  Review of the biological significance and rationale for the clinical potential of DNMT inhibitors in combination with other chemotherapeutics.

Unsafe SETs: Histone Lysine Methyltransferases and Cancer. Schneider R, Bannister AJ, Kouzarides T.
Wellcome/Cancer Research UK Institute and Department of Pathology, Tennis Court Road, Cambridge, UK CB2 1QR. Trends Biochem Sci. 2002 Aug;27(8):396-402. (PubMed Abstract)

SUMMARY: A review of the roles of lysine histone methyltransferases in carcinogenesis.  The methylation of lysine residues by these enzymes on the N-termini of core histone proteins plays a role in the regulation of nucleosome structure and the degree of availability of DNA for transcriptional control.

Epigenetics and Airways Disease. Adcock IM, Ford P, Ito K, Barnes PJ. Airways Disease Section, National Heart and Lung Institute, Imperial College London, UK. This email address is being protected from spambots. You need JavaScript enabled to view it.. Resp Res. 2006 Feb 6;7:21. (Full Text)

SUMMARY: A review of the role of epigenetic changes, and methylation in particular, in the inflammatory response in the lungs and the development of lung cancer.  It is speculated that these changes are potentially reversible, and thus, treatable.

Protein Methyltransferases as a Target Class for Drug Discovery. Copeland RA, Solomon ME, Richon VM, Nat Rev Drug Discov 2009; 8:724-732.

SUMMARY:  Review the biological, biochemical and structural data that together present protein methyltransferases as a novel, chemically tractable target class for drug discovery.

Epigenetics in Cancer. Sharma S, Kelly TK, Jones PA, Carcinogenesis 2010 Jan; 31(1):27-36.

SUMMARY:  Changes in the epigenetic regulation are a hallmark of cancer.  Discussion of the current understanding of alterations in the epigenetic landscape that occur in cancer and normal cell development, the roles of these changes in cancer initiation and progression, and the use of current information in designing more effective treatment strategies.

Molecular Recognition of Sub-Micromolar Inhibitors by the Epinephrine-Synthesizing Enzyme Phenylethanolamine N-Methyltransferase.  McMillan FM, Archbold J, McLeish MJ, Caine JM, Criscione KR, Grunewald GL, Martin JL, J Med Chem2004; 47:37-44.

SUMMARY:  The crystal structures of human phenylethanolamine N-methyltransferase in complex with S-adenosyl-l-homocysteine (AdoHcy) and inhibitors. These studies provide further clues for the development of improved inhibitors for use as pharmacological probes.

Structural Basis for Inhibition of Histamine N-Methyltransferase by Diverse Drugs.  Horton JR, Sawada K, Nishibori M, Cheng X, J Mol Biol 2005; 353:334-344.

SUMMARY:  The off target effects and structural mode of interaction is shown for histamine receptor H1 antagonist diphenhydramine, the antimalarial drug amodiaquine, the antifolate drug metoprine, and the anticholinesterase drug tacrine (an early drug for Alzheimer’s disease) of histamine receptor H1 with histamine N-methyltransferase (HNMT). All are surprisingly potent HNMT inhibitors, having inhibition constants in the range of 10-100nM.

RNA Modifications: a Mechanism that Modulates Gene Expression.  Karijolich J, Kantartzis A, Yu YT, Methods Mol Biol 2010; 629:1-19.

SUMMARY:  Review of the functional aspects of the posttranscriptional modifications of spliceosomal snRNA and rRNA providing a framework for understanding how modifications, including 2′-O-methylation, are capable of influencing gene expression.

1. A Universal Competitive Fluorescence Polarization Activity Assay for S-Adenosylmethionine Utilizing Methyltransferases. Tiffany L. Graves, Yi Zhang, and John E. Scott. Department of Pharmaceutical Sciences, Biomanufacturing Research Institute and Technology Enterprise, North Carolina Central University, Durham, NC 27707, USA. Anal Biochem. 2008 Feb15; 373(2):296-306. (Abstract).

SUMMARY: A competitive FPIA for SAH which utilizes an antibody to SAH and an SAH-fluorescein tracer.  This assay has some limitations in detection level and assay window due to the fact that the antibody cross-reacts with SAM.

2. Development and Validation of a Generic Fluorescent Methyltransferase Activity Assay Based on the Transcreener AMP/GMP Assay. Klink, TA, Staeben M, Twesten, K, Kopp AL, Kumar M, Schall Dunn R, Pinchard C, Kleman KM, Klumpp M, Lowery RG, JBC 2011, submitted.

SUMMARY:  Universal methyltransferase assay using coupling enzymes and fluorescent polarization immunoassay technology.

3. A Coupled Fluorescent Assay for Histone Methyltransferases.  Collazo E, Couture JF, Bulfer S, Trievel RC., Department of Biological Chemistry, University of Michigan, Ann Arbor, MI 48109-0606, USA. Anal Biochem. 2005 Jul 1;342(1):86-92.(Abstract).

SUMMARY: A coupled enzyme assay for histone methyltransferase activity where SAH is converted to adenosine and homocysteine by SAH hydrolase, then the adenosine is removed from the reaction by adenosine deaminase (inosine is the product).  The assay measures the resultant levels of sulfhydryl present from the homocysteine residues.

4. An Eenzyme-Coupled Continuous Spectrophotometric Assay for S-Adenosylmethionine-Dependent Methyltransferases.Dorgan KM, Wooderchak WL, Wynn DP, Karschner EL, Alfaro JF, Cui Y, Zhou ZS, Hevel JM. Department of Chemistry, Washington State University, Pullman, WA 99164, USA. Anal Biochem. 2006 Mar 15;350(2):249-55. (Abstract)

SUMMARY: This reference also describes a coupled enzymatic assay where SAH is converted to adenine (SAH nucleosidase), then adenine is deaminated to hypoxanthine which results in a drop in absorbance at 265nm.  The detection of this drop in absorbance correlates with increased methyltransferase activity.

5. An Enzyme-Coupled Ultrasensitive Luminescence Assay for Protein Methyltransferases.  Ibáñez G, McBean JL, Astudillo YM, Luo M. Molecular Pharmacology and Chemistry Program, Memorial Sloan-Kettering Cancer Center, New York, NY 10065, USA. Anal Biochem. 2010 Jun 15;401(2):203-10. (Abstract).

SUMMARY: This paper describes a coupled three enzyme assay which converts SAH to adenine, AMP and finally ATP, which is detected and quantified with a luciferase-based detection module.

6. A Continuous Protein Methyltransferase (G9a) Assay for Enzyme Activity Measurement and Inhibitor Screening.  Dhayalan A, Dimitrova E, Rathert P, Jeltsch A, J Biomol Screen 2009; 14:1129-1133.

SUMMARY:  Radioactive Flashplate assay using native substrate with dose response curves using AdoHcy and BIX-01294.

7. Continuous Enzymatic Assay for Histone Lysine Methyltransferases. Rathert P, Cheng X, Jeltsch A, BioTechniques 2007; 43:602, 604, 606 passim.

SUMMARY:  Streptavidin FlashPlate continuous peptide coated for Neurospora crassa Dim-5 histone H3 lysine 9 methyltransferase as a model system.

8. Small Molecule Regulators of Protein Arginine Methyltransferases.  Cheng D, Yadav N, King RW, Swanson MS, Weinstein EJ, Bedford MT, J Biol Chem 2004; 279:23892-23899.

SUMMARY:  Identification of small molecule inhibitors of histone methyltransferases including the selective arginine methyltransferase inhibitor AMI-1.

9. Reversal of H3K9me2 by a Small-Molecule Inhibitor for the G9a Histone Methyltransferase. Kubicek S, O’Sullivan RJ, August EM, Hickey ER, Zhang Q, Teodoro ML, Rea S, Mechtler K, Kowalski JA, Homon CA, Kelly TA, Jenuwein T, Mol Cell 2007; 25:473-481.

SUMMARY:  Screening for G9a MT specific inhibitors using a 125,000 chemical library yielded seven hits, including identification of the biologically active inhibitor, BIX-01294 in both biochemical and cellular based assays.

10. Accessing Protein Methyltransferase and Demethylase Enzymology Using Microfluidic Capillary Electrophoresis. Wigle TJ, Provencher LM, Norris JL, Jin J, Brown PJ, Frye SV, Janzen WP, Chem Biol 2010 July 30; 17:695-704.

SUMMARY: Using UPLC-MS/MS (ultra-performance liquid chromatography-tandem MS), gel electrophoresis and thin-layer chromatography, the authors characterize the enzymatic activity of a protein arginine N-methyltransferase which selectively methylates histone H4.

11. Fluorescence-based High-Throughput Assay for Human DNA (Cytosine-5)-Methyltransferase 1. Ye Y, Stivers JT, Anal Biochem 2010 June 1; 401:168-172.

SUMMARY: Nonradioactive HTS assay method that is suitable for human DNA (cytosine-5)-methyltransferase 1 (DNMT1). The introduction of the methylation site into the recognition sequence of a restriction endonuclease, and the use of a fluorogenic read-out method are the key attributes of the technology.

A Fast and Efficient Method for Quantitative Measurement of S-Adenosyl-L-Methionine-Dependent Methyltransferase Activity With Protein Substrates.; Brenda B. Suh-Lailam and Joan M. Hevel. (Journal Abstract). Department of Chemistry and Biochemistry, Utah State University, Logan, UT 84322, USA and Center for Integrated Biosystems, Utah State University, Logan, UT 84322, USA. Anal Biochem. 2010 Mar 15; 398(2):218-24. (PubMed Abstract)

SUMMARY: Radioactive assay method for measuring protein methyltransferase activity where reverse-phase resin packed at the end of pipette tip is used to separate unreacted SAM from radiolabeled protein products.

Kinetic Analysis of Human Protein Arginine N-Methyltransferase 2: Formation of Monomethyl- and Asymmetric Dimethyl-Arginine Residues on Histone H4. Ted M. Lakowski and Adam Frankel., Division of Biomolecular and Pharmaceutical Chemistry, Faculty of Pharmaceutical Sciences, The University of British Columbia, Vancouver, BC, Canada, V6T 1Z3.Biochem. J. 2009 Jun 26; 421(2):253-61. (Full Text).

SUMMARY: Using UPLC-MS/MS (ultra-performance liquid chromatography-tandem MS), gel electrophoresis and thin-layer chromatography, the authors characterize the enzymatic activity of a protein arginine N-methyltransferase which selectively methylates histone H4.

A Nonradioactive DNA Methyltransferase Assay Adaptable to High-Throughput Screening. Youn-Hi Woo, P.T. Ravi Rajagopalan, and Stephen J. Benkovic. 414 Wartik Laboratory, Department of Chemistry, Pennsylvania State University, University Park, PA 16802, USA. Anal Biochem. 2005 Mar13; 340:336-340. (Abstract).

SUMMARY: An assay for DNA methlytransferases based upon protection from restriction endonucleases, then detection by an ELISA in microtiter plates.

An Enzyme-Coupled Colorimetric Assay for S-Adenosylmethionine-Dependent Methyltransferases.Hendricks CL, Ross JR, Pichersky E, Noel JP, Zhou ZS.Department of Chemistry, Carnegie Mellon University, Pittsburgh, PA 15213, USA. Anal Biochem. 2004 Mar 1;326(1):100-05. (Abstract)

SUMMARY: This paper describes a coupled enzyme assay which converts SAH to S-ribosylhomocysteine, then homocysteine.  The thiol groups present in homocysteine are then detectable with a colorimetric assay.

A Real-Time Assay for CpG-Specific Cytosine-C5 Methyltransferase Activity. Wood RJ, McKelvie JC, Maynard-Smith MD, Roach PL. School of Chemistry, University of Southampton, Southampton, Hampshire, SO17 1BJ, UK. Nuc Acids Res. 2010 May; 38(9):e107. (Full Text)

SUMMARY: This paper describes an assay for monitoring DNA methyltransferase 1 (DNMT1) activity.  An oligonucleotide is cleaved by a methylation sensitive endonuclease to free a fluorophore from its quencher and yield an increase in fluorescence.

Epigenetics: Tools and Technologies.  Janzen WP, Wigle TJ, Jin J, Frye SV, Drug Discov Today Technol. 2010 Spring; 7(1):e59-e65; 7:e59-e65.

SUMMARY:  Very informative and concise summary of the current state of epigenetic drug discovery with a focus on assay methods for methyltransferases. Highlights the regulation of chromatin, the complex of histone proteins, RNA and DNA that efficiently packages the genome, by specific modifications to histone proteins and DNA, and the recognition of these marks by other proteins and protein complexes.

Small Molecule Regulators of Protein Arginine Methyltransferases.  Cheng D, Yadav N, King RW, Swanson MS, Weinstein EJ, Bedford MT, J Biol Chem 2004; 279:23892-23899.

SUMMARY:  Identification of small molecule inhibitors of histone methyltransferases including the selective arginine methyltransferase inhibitor AMI-1.

Reversal of H3K9me2 By a Small-Molecule Inhibitor for the G9a Histone Methyltransferase. Kubicek S, O’Sullivan RJ, August EM, Hickey ER, Zhang Q, Teodoro ML, Rea S, Mechtler K, Kowalski JA, Homon CA, Kelly TA, Jenuwein T, Mol Cell 2007; 25:473-481.

SUMMARY:  Screening for G9a MT specific inhibitors using a 125,000 chemical library yielded seven hits, including identification of the biologically active inhibitor, BIX-01294 in both biochemical and cellular based assays.

State of the Arg: Protein Methylation at Arginine Comes of Age. Anne E. McBride1 and Pamela A. Silver; Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Department of Cancer Biology, Dana-Farber Cancer Institute, Boston, MA 02115 USA. Cell 2001 July; 106:5-8.(Full Text).

SUMMARY: Mini-review of arginine methylation and its many effects on protein function.

Gene-Specific Targeting of H3K9 Methylation Is Sufficient for Initiating Repression In Vivo. Andrew W Snowden, Philip D Gregory, Casey C Casea and Carl O Paboa. Sangamo BioSciences, Point Richmond Tech Center, 501 Canal Boulevard, Suite A100, Richmond, CA 94804 USA. Curr Biol. 2002 Dec;12(24):2159-66. (PubMed Abstract).

SUMMARY: Histone H3 lysine 9 (H3K9) methylation of DNA is an epigenetic signal which correlates with gene silencing.  Early experiments confirm this role.

Substrate Specificity and Kinetic Mechanism of Mammalian G9a Histone H3 Methyltransferase. Patnaik D, Chin HG, Esteve PO, Benner J, Jacobsen SE, Pradhan S, J Biol Chem 2004; 279:53248-53258.

Functional Analysis of Genetic Variation in Catechol-O-Methyltransferase (COMT): Effects on mRNA, Protein, and Enzyme Activity in Postmortem Human Brain. Chen J, Lipska BK, Halim N, Ma QD, Matsumoto M, Melhem S, Kolachana BS, Hyde TM, Herman MM, Apud J, Egan MF, Kleinman JE, Weinberger DR. Clinical Brain Disorders Branch, Genes, Cognition, and Psychosis Program, National Institute of Mental Health, National Institutes of Health, Bethesda, MD 20892, USA. Am J Hum Genet 2004 Nov:75(5):807-821. (PubMed FullText)

SUMMARY: An analysis of the expression and allelic differences of catechol-O-methyltransferase (important in the elimination of dopamine in the prefrontal cortex) in normal and schizophrenic brain. Increased COMT activity (but not necessarily expression) in the prefrontal cortex leads to an increased risk of clinical disorders by disrupting dopamine signaling.

Purification and Characterization of Streptomyces Griseus Catechol-O-Methyltransferase. Dhar K, Rosazza JP. Division of Medicinal and Natural Products Chemistry, Center for Biocatalysis and Bioprocessing, College of Pharmacy, University of Iowa, Iowa City, Iowa 52242, USA. Appl Environ Microbiol 2000 Nov;66(11):4877-4882. (PubMed FullText)

SUMMARY: A method paper for purification, enzymatic (including substrate specificity) and kinetic analysis of a bacterial COMT.

Multiple Molecular Forms of Catechol-O-Methyltransferase. Evidence forTtwo Distinct Forms, and Their Purification and Physical Characterization. Huh MM, Friedhoff AJ. The Millhauser Laboratories, New York University School of Medicine, New York, New York 10016. J Biol Chem. 1979 Jan25;254(2):299-308. (Journal FullText)

SUMMARY: Describes the purification and enzymatic characterization of two forms of COMT from rat liver.

Catechol-O-Methyltransferase (COMT)-Mediated Methylation Metabolism of Endogenous Bioactive Catechols and Modulation by Endobiotics and Xenobiotics: Importance in Pathophysiology and Pathogenesis.  Zhu BT, Curr Drug Metab2002; 3:321-349.

SUMMARY:  Overview of the COMT metabolic system, particularly areas: (i) the regulation of this catechol metabolizing system by S-adenosyl-L-homocysteine and homocysteine; (ii) risk factors associated with the development of neurodegenerative disorders and cardiovascular diseases and (iii) the importance of the COMT-catalyzed O-methylation metabolism in cancer.

InVitro Characterization of the Enzyme Properties of the Phospholipid N-Methyltransferase PmtA from Agrobacterium Tumefaciens. Meriyem Aktas and Franz Narberhaus. Microbial Biology, Ruhr-University, Bochum, Germany: Lehrstuhl für Biologie der Mikroorganismen, Fakultät für Biologie und Biotechnologie, Ruhr-Universität Bochum, Universitätsstrasse 150, NDEF 06/783, D-44780 Bochum, Germany. Phone: 49 (234) 322 3100. Fax: 49 (234) 321 4620. E-mail: This email address is being protected from spambots. You need JavaScript enabled to view it.. J Bacteriol 2009 April:191(7):2033-2041. (PubMed FullText)

SUMMARY: A description of a bacterial lipid methyltransferase which performs a central role in the bacterium’s infectious capabilities

BellBrook’s SAH Methyltransferase Assay Kits

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In addition to our Methyltransferase Assays, Bellbrook Labs also offers the following products and services to aid in the drug discovery process: