SEQUENCE-SPECIFIC DETECTION OF METHYLATION IN BIOMOLECULES

摘要

The present invention relates to a method for detecting sequence specific methylation in a biomolecule, comprising: (a) contacting a biomolecule with an S-adenosyl-L-methionine-dependent methyltransferase in the presence of a detectable cofactor of said methyltransferase; and (b) detecting whether the recognition sequence of said methyltransferase has been modified with the cofactor or a derivative thereof, wherein modification of the recognition sequence of said methyltransferase is indicative of an absence of methylation at said recognition sequence. The present invention also relates to a cofactor which is specific for S-adenosyl-L-methionine-dependent methyltransferases, wherein said cofactor is an N-adenosylaziridine derivative with a reporter group attached to the 6 or 7 position of the adenine ring or attached to the aziridine ring. Moreover, the present invention relates to a complex of the cofactor of the present invention and a methyltransferase which normally uses S-adenosyl-L-methionine (AdoMet) as a cofactor. In addition, the present invention relates to a diagnostic composition comprising the cofactor of the present invention or the complex of the present invention. Finally, the present invention relates to the use of the cofactor of the present invention or the complex of the present invention for detecting sequence-specific methylation in DNA molecules.