Cross-Ring Fragmentation Patterns in the Tandem Mass Spectra of Underivatized Sialylated Oligosaccharides and Their Special Suitability for Spectrum Library Searching.

Reference spectral library searching, while widely used to identify compounds in other areas of mass spectrometry, is not commonly used in glycomics. Building on a study by Cotter and coworkers on analysis of sialylated oligosaccharides using atmospheric pressure-matrix-assisted laser-induced tandem mass spectrometry (MS/MS), we show that library search methods enable the automated differentiation of such sialylated oligosaccharide isomers using MS/MS derived from electrospray collision-induced dissociation in ion trap and beam-type fragmentation mass spectrometers. We compare MS/MS spectra of five sets of native sialylated oligosaccharide isomers and show a spectral library search method that can distinguish between these isomers using the precursor ion [M+2X-H], where X=Li, Na, or K.

Creating a Mass Spectral Reference Library for Oligosaccharides in Human Milk.

We report the development and availability of a mass spectral reference library for oligosaccharides in human milk. This represents a new variety of spectral library that includes consensus spectra of compounds annotated through various data analysis methods, a concept that can be extended to other varieties of biological fluids. Oligosaccharides from the NIST Standard Reference Material (SRM) 1953, composed of human milk pooled from 100 breastfeeding mothers, were identified and characterized using hydrophilic interaction liquid chromatography electrospray ionization tandem mass spectrometry (HILIC-ESI-MS/MS) and the NIST 17 Tandem MS Library.

Human milk oligosaccharides in premature infants: absorption, excretion, and influence on the intestinal microbiota.

Background: Human milk oligosaccharides (HMOs) shape the intestinal microbiota in term infants. In premature infants, alterations in the intestinal microbiota (dysbiosis) are associated with risk of necrotizing enterocolitis (NEC) and sepsis, and the influence of HMOs on the microbiota is unclear.

Methods: Milk, urine, and stool specimens from 14 mother-premature infant dyads were investigated by mass spectrometry for HMO composition.

Human milk glycomics and gut microbial genomics in infant feces show a correlation between human milk oligosaccharides and gut microbiota: a proof-of-concept study.

Human milk oligosaccharides (HMOs) play a key role in shaping and maintaining a healthy infant gut microbiota. This article demonstrates the potential of combining recent advances in glycomics and genomics to correlate abundances of fecal microbes and fecal HMOs. Serial fecal specimens from two healthy breast-fed infants were analyzed by bacterial DNA sequencing to characterize the microbiota and by mass spectrometry to determine abundances of specific HMOs that passed through the intestinal tract without being consumed by the luminal bacteria.

A quantitative and comprehensive method to analyze human milk oligosaccharide structures in the urine and feces of infants.

Human milk oligosaccharides (HMOs), though non-nutritive to the infant, shape the intestinal microbiota and protect against pathogens during early growth and development. Infant formulas with added galacto-oligosaccharides have been developed to mimic the beneficial effects of HMOs. Premature infants have an immature immune system and a leaky gut and are thus highly susceptible to opportunistic infections.

The glycolyzer: automated glycan annotation software for high performance mass spectrometry and its application to ovarian cancer glycan biomarker discovery.

Human serum glycomics is a promising method for finding cancer biomarkers but often lacks the tools for streamlined data analysis. The Glycolyzer software incorporates a suite of analytic tools capable of identifying informative glycan peaks out of raw mass spectrometry data. As a demonstration of its utility, the program was used to identify putative biomarkers for epithelial ovarian cancer from a human serum sample set.

Lacto-N-tetraose, fucosylation, and secretor status are highly variable in human milk oligosaccharides from women delivering preterm.

Breast milk is the ideal nutrition for term infants but must be supplemented to provide adequate growth for most premature infants. Human milk oligosaccharides (HMOs) are remarkably abundant and diverse in breast milk and yet provide no nutritive value to the infant. HMOs appear to have at least two major functions: prebiotic activity (stimulation of the growth of commensal bacteria in the gut) and protection against pathogens.

Identification and accurate quantitation of biological oligosaccharide mixtures.

Structure-specific characterization and quantitation is often required for effective functional studies of oligosaccharides. Inside the gut, HMOs are preferentially bound and catabolized by the beneficial bacteria. HMO utility by these bacteria employs structure-specific catabolism based on a number of glycosidases.

High-mannose glycans are elevated during breast cancer progression.

Alteration in glycosylation has been observed in cancer. However, monitoring glycosylation changes during breast cancer progression is difficult in humans. In this study, we used a well-characterized transplantable breast tumor mouse model, the mouse mammary tumor virus-polyoma middle T antigen, to observe early changes in glycosylation.

Human serum processing and analysis methods for rapid and reproducible N-glycan mass profiling.

Glycans constitute a new class of compounds for biomarker discovery. Glycosylation is a common post-translational modification and is often associated with transformation to malignancy. To analyze glycans, they are released from proteins, enriched, and measured with mass spectrometry.

Glycomics and disease markers.

Glycomics is the comprehensive study of all glycans expressed in biological systems. The biosynthesis of glycan relies on a number of highly competitive processes involving glycosyl transferases. Glycosylation is therefore highly sensitive to the biochemical environment and has been implicated in many diseases including cancer.

Glycomic approach for potential biomarkers on prostate cancer: profiling of N-linked glycans in human sera and pRNS cell lines.

Prostate cancer is a leading cause of cancer death among men. Currently available screening test measures prostate-specific antigen (PSA) to detect prostate cancer. However, this test produces false positive values that often lead to negative biopsies.