SAM510TM, SAM Methyltransferase assay
Methylation of key biological molecules and proteins plays important roles in numerous biological systems,
including signal transduction, biosynthesis, protein repair, gene silencing and chromatin regulation.
The S-adenosylmethionine (SAM) dependent methyltransferases use SAM, the second most commonly
used enzymatic cofactor after ATP. SAM, also known as AdoMet, acts as a donor of a methyl group that is
required for the modification of proteins and DNA. Aberrant levels of SAM have been linked to many
abnormalities, including Alzheimer’s, depression, Parkinson’s, multiple sclerosis, liver failure and cancer.
The SAM510™: SAM Methyltransferase Assay is a continuous enzyme coupled assay that can continuously
monitor purified SAM-dependent methyltransferases without the use of radioactive labels or endpoint
Figure in below outlines the general scheme of the assay. Basically, the removal of the methyl group from
SAM generates S-adenosylhomocysteine, which is rapidly converted to S-ribosylhomocysteine and adenine
by the included adenosylhomocysteine nucleosidase. This rapid conversion prevents the buildup of
adenosylhomocysteine and its feedback inhibition on the methylation reaction. Finally, the adenine is
converted to hypoxanthine, by adenine deaminase, which in turn is converted to urate and hydrogen
peroxide. The rate of production of hydrogen peroxide is measured with a colorimetric assay by an increase
in absorbance at 510nm.
The assay can be adapted to be used with any purified SAM dependent methyltransferase or a purified
enzyme that produces 5-adenosylhomocysteine or 5'-methylthioadenosine, due to the specificity of
The kit is supplied with enough reagents for 100 x 115µl microwell assays.
A UV SAM methyltransferase assay and a fluorescent SAM methyltransferase assay are also available.
• Kinetic analysis of purified methyltransferases or screening methylation inhibitors.
• Continuous enzyme coupled assay for kinetic studies.
• Colorimetric, non radioactive assay.
• Supplied with all reagents, including positive control.
• Adaptable for enzymes that generate S-adenosylhomocysteine or 5'-methylthioadenosine.
• For the kinetic analysis of protein SAM methyltransferase enzymes.
• Ideal for screening of methyltransferase inhibitors.
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Instruction sheet (PDF)