title: N-mustard analogs of S-adenosyl-L-methionine as biochemical probes of protein arginine methylation.
abstract: Nucleosomes, the fundamental building blocks of eukaryotic chromatin, undergo post-synthetic modifications and play a major role in the regulation of transcriptional processes. Combinations of these modifications, including methylation, regulate chromatin structure, determining its different functional states and playing a central role in differentiation. The biological significance of cellular methylation, particularly on chromatin, is widely recognized, yet we know little about the mechanisms that link biological methylation events. To characterize and fully understand protein methylation, we describe here novel N-mustard analogs of S-adenosyl-l-methionine (SAM) as biochemical tools to better understand protein arginine methylation events using protein arginine methyltransferase 1 (PRMT1). Specifically, azide- and alkyne-functionalized N-mustard analogs serve as cofactor mimics of SAM and are enzymatically transferred to a model peptide substrate in a PRMT1-dependent fashion. Once incorporated, the resulting alkynes and azides can be modified through chemoselective ligations, including click chemistry and the Staudinger ligation. These results readily demonstrate the feasibility of utilizing N-mustard analogs as biochemical tools to site-specifically label substrates of PRMT1 and serve as an alternative approach to study protein methylation events.
authors.affiliation: Wake Forest University, Department of Chemistry, Winston-Salem, NC 27106, United States.
authors.forename: Sarah J
authors.initials: SJ
authors.lastname: Hymbaugh Bergman
authors.affiliation: Wake Forest University, Department of Chemistry, Winston-Salem, NC 27106, United States. Electronic address: comstolr@wfu.edu.
authors.forename: Lindsay R
authors.initials: LR
authors.lastname: Comstock
mesh_terms: D000480:Alkynes / Q000737:chemistry; D000595:Amino Acid Sequence; D001120:Arginine / Q000737:chemistry / Q000378:metabolism*; D001386:Azides / Q000737:chemistry; D019921:Biotinylation; D002851:Chromatography, High Pressure Liquid; D057930:Click Chemistry; D006801:Humans; D008745:Methylation; D008969:Molecular Sequence Data; D011484:Protein-Arginine N-Methyltransferases / Q000737:chemistry / Q000378:metabolism; D012097:Repressor Proteins / Q000737:chemistry / Q000378:metabolism; D012436:S-Adenosylmethionine / Q000031:analogs & derivatives* / Q000032:analysis / Q000378:metabolism; D021241:Spectrometry, Mass, Electrospray Ionization
chemical_list: D000480:Alkynes; D001386:Azides; D012097:Repressor Proteins; D012436:S-Adenosylmethionine; D001120:Arginine; C099988:PRMT1 protein, human; D011484:Protein-Arginine N-Methyltransferases
keywords: Arginine methylation; Chemoselective ligation; PRMT1; SAM analog