A direct structural identification, and quantitative assessment below the 50 nmol/ml level, of the full pattern of renally excreted metabolites is made possible by 13C NMR measurements of untreated urine samples when stable isotope-labelled (13C) drug analogues are administered to humans. The full potential of the new ex vivo NMR approach is exemplified by a study, for a group of volunteers, of S-carboxymethyl-L-cysteine metabolism. The metabolic sulphoxidation pathway of S-carboxymethyl-L-cysteine in man, accepted so far, needs to be profoundly revised on the basis of the 13C NMR results.
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http://dx.doi.org/10.1515/znc-1990-11-1215 | DOI Listing |
Nature
January 2025
Department of Chemistry and Chemical Biology, Boyce Thompson Institute, Cornell University, Ithaca, NY, USA.
Metabolites derived from the intestinal microbiota, including bile acids (BA), extensively modulate vertebrate physiology, including development, metabolism, immune responses and cognitive function. However, to what extent host responses balance the physiological effects of microbiota-derived metabolites remains unclear. Here, using untargeted metabolomics of mouse tissues, we identified a family of BA-methylcysteamine (BA-MCY) conjugates that are abundant in the intestine and dependent on vanin 1 (VNN1), a pantetheinase highly expressed in intestinal tissues.
View Article and Find Full Text PDFAnalyst
January 2025
Segal Cancer Proteomics Centre, Lady Davis Institute, Jewish General Hospital, McGill University, Montréal, Quebec, H3T 1E2, Canada.
Here we show that when using a mix of 274 light synthetic peptide standards (NAT) as surrogates for 270 human plasma proteins, as well as stable isotope-labelled standards (SIS) as normalizers (both from MRM Proteomics Inc.) for targeted quantitative analysis by liquid chromatography multiple reaction monitoring mass spectrometry (LC/MRM-MS), the Seer Proteograph™ platform allowed for the enrichment and absolute quantitation of up to an additional 62 targets (median) compared to two standard proteomic workflows without enrichment, representing an increase of 44%. The nanoparticle-based fractionation workflow resulted in improved reproducibility compared to a traditional proteomic workflow with no fractionation (median 8.
View Article and Find Full Text PDFJ Chromatogr A
January 2025
Metabolomics and Analytics Centre, Leiden Academic Centre for Drug Research, Leiden University, Leiden, the Netherlands. Electronic address:
Front Immunol
October 2024
AMYRA Biotech AG, Basel, Switzerland.
Introduction: Celiac disease is a common autoimmune-like enteropathy caused by an aberrant response to incompletely digested dietary gluten. Gluten immunogenic peptides including the immunodominant 33-mer are thought to be resistant to proteolytic digestion by human gastrointestinal peptidases. We developed a novel enzyme therapy approach to support gluten peptide digestion using a combination of two tandem-acting exopeptidases, AMYNOPEP, that complement the intrinsic enzymatic activity of intestinal brush border enterocytes.
View Article and Find Full Text PDFWellcome Open Res
August 2024
Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, 10400, Thailand.
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