Journal: ACS Infectious Diseases
Article Title: Elucidation of a Human Urine Metabolite as a Seryl-Leucine Glycopeptide and as a Biomarker of Effective Anti-Tuberculosis Therapy
Figure Lengend Snippet: Enzymatic deglycosylation and MS confirmation of core 1 glycosylation. MF 874.3547 untreated (A, C, E, G, I) and treated with α2-3,6,8 neuraminidase and O -glycosidase (B, D, F, H, J) were analyzed by LC-MS, and the spectra were evaluated by extracted ion chromatogram (EIC) for intact glycopeptide (A and B), the glycopeptide minus Neu5Ac (C and D), the Hex–HexNAc disaccharide (E and F), Neu5Ac (G and H), and the deglycosylated putative diamino acid S/TX (I and J). The * in panel C indicates a low level of the glycopeptide minus Neu5Ac ( m / z 584.2661) present in the undigested sample. Note the level of this product was considerably higher following digestion (G). In source fragmentation of SLC1G yielded the m / z 584.2661 product (# in panel C) at the same retention time as the undigested glycopeptide.
Article Snippet: MF 874.3547 (9 μL) or standards (60 ng) of 4-nitrophenyl O -(N -acetyl-α-neuraminosyl)-(2-6)-β-d -galactopyranosyl-(1-4)-2-acetamido-2-deoxy-β-d -glucopyranoside (EN4614, Carbosynth Ltd., San Diego, CA), glycan-F58 (ULM-10078-CA, Cambridge Isotope Laboratories, Inc., Tewksbury, MA), and Sialo Anti-Proliferative Factor (GP131025, Sussex Research Laboratories, Ottawa, ON) were treated with α2-3 neuraminidase S (PO743S), α2-3,6,8 neuraminidase (#P0720S, New England Biolabs Inc., Ipswich, MA, USA), and O -glycosidase (#P0733S, New England Biolabs Inc.).
Techniques: Mass Spectrometry, Liquid Chromatography with Mass Spectroscopy