title: Phosphorothioation of oligonucleotides strongly influences the inhibition of bacterial (M.HhaI) and human (Dnmt1) DNA methyltransferases.
abstract: Methyltransferase inhibitors: Short double-stranded oligonucleotides that have a hemimethylated target sequence and 5-fluoro-2'-deoxycytidine as a suicide inhibitor as well as their phosphorothioated analogues were tested for their ability to inhibit the bacterial methyltransferase M.HhaI and the human Dnmt1 in vitro.The cytidine analogue 5-fluoro-2'-deoxycytidine (dC(F)) is a mechanism-based inhibitor of DNA methyltransferases. We report the synthesis of short 18-mer dsDNA oligomers containing a triple-hemimethylated CpG motive as a recognition sequence for the human methyltransferase Dnmt1. The DNA strands carry within these CpG islands dC(F) building blocks that function as mechanism-based inhibitors of the analyzed methyltransferases. In addition, we replaced the phosphodiester backbones at defined positions by phosphorothioates. These hypermodified DNA strands were investigated as inhibitors of the DNA methyltransferases M.HhaI and Dnmt1 in vitro. We could show that both methylases behave substantially differently in respect to the amount of DNA backbone modification.
authors.affiliation: Center for Integrative Protein Science, Department for Chemistry and Biochemistry, Ludwig-Maximilians University Munich, Butenandtstrasse 5-13, Munich, Germany.
authors.forename: Simon
authors.initials: S
authors.lastname: Warncke
authors.forename: Aline
authors.initials: A
authors.lastname: Gégout
authors.forename: Thomas
authors.initials: T
authors.lastname: Carell
mesh_terms: D000818:Animals; D001483:Base Sequence; D004247:DNA / Q000737:chemistry / Q000235:genetics / Q000378:metabolism / Q000494:pharmacology; D000076123:DNA (Cytosine-5-)-Methyltransferase 1; D004248:DNA (Cytosine-5-)-Methyltransferases / Q000037:antagonists & inhibitors* / Q000378:metabolism; D004586:Electrophoresis; D006190:Haemophilus / Q000201:enzymology*; D006801:Humans; D008780:Methyltransferases / Q000037:antagonists & inhibitors* / Q000378:metabolism; D009838:Oligodeoxyribonucleotides / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism / Q000494:pharmacology*; D010710:Phosphates / Q000737:chemistry*; D015183:Restriction Mapping; D044366:Transition Temperature
chemical_list: D009838:Oligodeoxyribonucleotides; D010710:Phosphates; C083120:phosphorodithioic acid; D004247:DNA; D008780:Methyltransferases; D000076123:DNA (Cytosine-5-)-Methyltransferase 1; D004248:DNA (Cytosine-5-)-Methyltransferases; C000619380:DNMT1 protein, human