New sulfatase-based assay for the selective identification of sulfate esters in human urine and fecal samples.

The chemical proteomic properties of five diazirine-based, fully-functionalized photoaffinity tags, including a newly developed, minimal tag, were compared. This study provides guidance for the development of new photoaffinity probes.

The microbiome has af undamental impact on the human hostsp hysiology through the production of highly reactive compounds that can lead to disease development. One class of such compounds are carbonyl-containing metabolites, which are involved in diverse biochemical processes.M ass spectrometry is the method of choice for analysis of metabolites but carbonyls are analytically challenging. Herein, we have developed an ew chemical biology tool using chemoselective modification to overcome analytical limitations.T wo isotopic probes allowf or the simultaneous and semi-quantitative analysis at the femtomole level as well as qualitative analysis at attomole quantities that allows for detection of more than 200 metabolites in human fecal, urine and plasma samples. This comprehensive mass spectrometric analysis enhances the scope of metabolomics-driven biomarker discovery.Weanticipate that our chemical biology tool will be of general use in metabolomics analysis to obtain ab etter understanding of microbial interactions with the human host and disease development.

While metabolites derived from gut microbiota metabolism have been linked to disease development in the human host, the chemical tools required for their detailed analysis and the discovery of biomarkers are limited. A unique and multifunctional chemical probe for mass spectrometric analysis, which contains p-nitrocinnamyloxycarbonyl as a new bioorthogonal cleavage site has been designed and synthesized. Coupled to magnetic beads, this chemical probe allows for straightforward extraction of metabolites from human samples and release under mild conditions. This isolation from the sample matrix results in significantly reduced ion suppression, an increased mass spectrometric sensitivity, and facilitates the detection of metabolites in femtomole quantities. The chemoselective probe was applied to the analysis of human fecal samples, resulting in the discovery of four metabolites previously unreported in this sample type and confirmation of the presence of medically relevant gut microbiota-derived metabolites.

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Phosphoryl group transfer is central to genetic replication, cellular signalling and many metabolic processes. Understanding the mechanisms of phosphorylation and phosphate ester and anhydride cleavage is key to efforts towards biotechnological and biomedical exploitation of phosphate-handling enzymes. Analogues of phosphate esters and anhydrides are indispensable tools, alongside protein mutagenesis and computational methods, for the dissection of phosphoryl transfer mechanisms. Hydrolysable and non-hydrolysable phosphate analogues have provided insight into the nature and sites of phosphoryl transfer processes. Kinetic isotope effects and crystallography using transition state analogues have painted more detailed pictures of transition states and how enzymes work to stabilise them.

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New chemoselective method permits detection of 112 metabolic ketones and aldehydes in human samples due to significantly increased mass spectrometric sensitivity.