Automatic Full Glycan Structural Determination through Logically Derived Sequence Tandem Mass Spectrometry

Abstract

Glycans have diverse functions and play vital roles in many biological systems, such as influenza, vaccines, and cancer biomarkers. However, full structural identification of glycans remains challenging. The glycan structure was conventionally determined by chemical methods or NMR spectroscopy, which require a large amount of sample and are not readily applicable for glycans extracted from biological samples. Although it has high sensitivity and is widely used for structural determination of molecules, current mass spectrometry can only reveal parts of the glycan structure. Herein, the full structures of glycans, including diastereomers, the anomericity of each monosaccharide, and the linkage position of each glycosidic bond, which can be determined by using tandem mass spectrometry guided by a logically derived sequence (LODES), are shown. This new method provides de novo oligosaccharide structural identification with high sensitivity and has been applied to automatic in situ structural determination of oligosaccharides eluted by means of HPLC. It is shown that the structure of a given trisaccharide from a trisaccharide mixture and bovine milk were determined from nearly 3000 isomers by using 6–7 logically selected collision‐induced dissociation spectra. The entire procedure for mass spectrometry measurement guided by LODES can be programmed in a computer for automatic full glycan structure identification.

Differentiation of aldohexoses and ketohexoses through collision‐induced dissociation

“…The experimental method has been described in detail in our previous works, [ 7–9 ] and is described briefly here. d ‐Glucose (≥99.5%, GC), d ‐galactose (≥99%), d ‐mannose (≥99%), d ‐allose (≥98%), d ‐altrose (≥97%), d ‐talose (≥99%), d ‐fructose (≥99%), d ‐psicose (≥95%), d ‐tagatose (≥98.5%), and l ‐sorbose (≥98%) were purchased from Sigma‐Aldrich (St. Louis, MO); d ‐gulose (≥99%), d ‐idose (≥95%), and β‐Gal p ‐(1 → 3)‐Gal p (85%) were purchased from Carbosynth Ltd. (San Diego, CA); d ‐[4,5‐ 13 C 2 ]fructose (99 atom‐% 13 C) was purchased from Omicron Biochemicals Inc. (South Bend, IN).…”

“…Recently, we have developed a new mass spectrometry method, namely logically derived sequence tandem mass spectrometry, for carbohydrate structural determination. [ 7–11 ] Three stereoisomers, glucose, galactose, and mannose, can be differentiated using MS 3 collision‐induced dissociation (CID) tandem mass spectrometry of lithium adducts. [ 9 ] This method is currently the only mass spectrometry method in which anomericity of glycosidic bonds and stereoisomers of monosaccharides can be identified.…”

“…[ 7–11 ] Three stereoisomers, glucose, galactose, and mannose, can be differentiated using MS 3 collision‐induced dissociation (CID) tandem mass spectrometry of lithium adducts. [ 9 ] This method is currently the only mass spectrometry method in which anomericity of glycosidic bonds and stereoisomers of monosaccharides can be identified. This method can be used for structural determination of monosaccharides produced from the CID of oligosaccharides in mass spectrometer.…”

Effective Separation of Human Milk Glycosides using Carbon Dioxide Supercritical Fluid Chromatography

“…Techniques such as mass spectrometry (MS), [10] nuclear magnetic resonance, [11,12] infrared spectroscopy, [13] microarray, [14] gas chromatography, [15] capillary electrophoresis, [16,17] and liquid chromatography (LC) [18] have been used to separate and analyze carbohydrates. Among these methodologies, promising MS‐based techniques such as ion‐mobility MS [19,20] and logically derived sequence tandem MS [21] have been developed for glycan analysis, particularly for the elucidation of structural information. However, chromatographic resolution remains the most favored and cost‐effective approach, particularly in preparative‐scale separation with appropriate stationary phases.…”

Unusual milk oligosaccharides and the biosynthetic pathways

“…Recently, a new mass spectrometry method, namely logically derived sequence (LODES) multistage tandem mass spectrometry (MS n ) was developed for the full structural determination of oligosaccharides [35][36][37][38] . This method can be used to determine oligosaccharide structures including linkage positions, anomericities, and monosaccharide stereoisomers.…”