A sensitive mass spectrum assay to characterize engineered methionine adenosyltransferases with S-alkyl methionine analogues as substrates.

ABSTRACT: Methionine adenosyltransferases (MATs) catalyze the formation of S-adenosyl-l-methionine (SAM) inside living cells. Recently, S-alkyl analogues of SAM have been documented as cofactor surrogates to label novel targets of methyltransferases. However, these chemically synthesized SAM analogues are not suitable for cell-based studies because of their poor membrane permeability. This issue was recently addressed under a cellular setting through a chemoenzymatic strategy to process membrane-permeable S-alkyl analogues of methionine (SAAMs) into the SAM analogues with engineered MATs. Here we describe a general sensitive activity assay for engineered MATs by converting the reaction products into S-alkylthioadenosines, followed by high-performance liquid chromatography-tandem mass spectrometry (H

SUBMITTER: Wang R 

PROVIDER: S-EPMC3947680 | biostudies-literature | 2014 Apr

REPOSITORIES: biostudies-literature