Patent ID: 8129106

Claim:
A method for detecting sequence specific methylation in a biomolecule having a recognition site for an AdoMet, 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 site of said methyltransferase has been modified with the cofactor, wherein modification of the recognition site is indicative of an absence of methylation at said recognition site; wherein the cofactor is an N-adenosylaziridine derivative represented by formula (I), wherein W is selected from N and CH, X is N or CR 1 , Y is NH 2 or NHR 2 , Z is H, R 3 or CH 2 CH(COOH)(NH 2 ), with the proviso that if X is CR 1 , Y is NH 2 and Z is H or CH 2 CH(COOH)(NH 2 ), if X is N and Y is NHR 2 , Z is H or CH 2 CH(COOH)(NH 2 ), if X is N and Y is NH 2 , Z is R 3 , R 1 is selected from —(CH 2 ) n R 4 , —(CH═CH) m (CH 2 ) n R 4 , —(CH 2 ) o (CH═CH) m (CH 2 ) n R 4 , —(C≡C) m (CH 2 ) n R 4 , —(C≡C) m (C 6 H 4 ) o (CH 2 ) n R 4 , —(C 6 H 4 ) m (CH 2 ) n R 4 , —CO(CH 2 ) n R 4 and —S(CH 2 ) n R 4 ; R 2 is selected from —(CH 2 ) n R 4 , —(C 6 H 4 ) m (CH 2 ) n R 4 and —CO(CH 2 ) n R 4 ; R 3 is selected from —(CH 2 ) n R 4 , —(CH═CH) m (CH 2 ) m R 4 , —(C≡C) m (CH 2 ) n R 4 , —(C 6 H 4 ) m (CH 2 ) n R 4 and —CONH(CH 2 ) n R 4 ; R 4 is selected from —NHR 5 , —NHCO(CH 2 ) p SR 5 , —SR S , —OR 5 , —O(C 2 H 5 O) n (C 2 H 5 )NHR 5 , —CH 2 NHNHR 5 , —NHCOCH(CH 2 SH)NHR 5 and —CONHR 5 ; R 5 is selected from fluorophores, affinity tags, crosslinking agents, chromophors, proteins, peptides, amino acids which may optionally be modified, nucleotides, nucleosides, nucleic acids, carbohydrates, lipids, PEG, transfection reagents, beads, intercalating agents, nucleic acid cleaving reagents and nanoparticles; n, m, o and p are independently selected from 0 or an integer from 1 to 5000.