ABSTRACT
Reactive electrophilic intermediates such as coenzyme A esters play central roles in metabolism but are difficult to detect with conventional strategies. Here, we introduce hydroxylamine-based stable isotope labeling to convert reactive electrophilic intermediates into stable derivatives that are easily detectable via LC-MS. In the model system Caenorhabditis elegans, parallel treatment with 14NH2OH and 15NH2OH revealed >1000 labeled metabolites, e.g., derived from peptide, fatty acid, and ascaroside pheromone biosyntheses. Results from NH2OH treatment of a pheromone biosynthesis mutant, acox-1.1, suggested upregulation of thioesterase activity, which was confirmed by gene expression analysis. The upregulated thioesterase contributes to the biosynthesis of a specific subset of ascarosides, determining the balance of dispersal and attractive signals. These results demonstrate the utility of NH2OH labeling for investigating complex biosynthetic networks. Initial results with Aspergillus and human cell lines indicate applicability toward uncovering reactive metabolomes in diverse living systems.
Subject(s)
Biosynthetic Pathways , Hydroxylamine/metabolism , Animals , Aspergillus/metabolism , Caenorhabditis elegans/metabolism , Cell Line , Chromatography, Liquid/methods , Humans , Isotope Labeling/methods , Mass Spectrometry/methods , Metabolome , Metabolomics/methodsABSTRACT
Seven mycobacteriophages from distinct geographical locations were isolated, using Mycobacterium smegmatis mc2155 as the host, and then purified and sequenced. All of the genomes are related to cluster A mycobacteriophages, BobSwaget and Lokk in subcluster A2; Fred313, KADY, Stagni, and StepMih in subcluster A3; and MyraDee in subcluster A18, the first phage to be assigned to that subcluster.
