Identification of Monosialylated N-glycoforms in the CDG Urinome by Ion Mobility Tandem Mass Spectrometry: The Potential for Clinical Applications

Sergey Y Vakhrushev,Iain Campuzano,James Langridge,Jasna Peter-Katalinić,Chris Hughes

doi:10.1007/s12014-008-9010-3

Abstract

Abstract Introduction A novel approach of ion mobility tandem mass spectrometry (IMS-MS/MS) is applied to analysis of human glycourinome to obtain carbohydrate pattern data of congenital disorders of glycosylation patient. Overlapping of the complex carbohydrate mass range landscape has been highly reduced upon IMS-MS procedure, allowing more efficient identification by mapping and sequencing of glycan precursor ions, following their separation by mobility, according to difference in drift time through the traveling wave IMS cell. Intact and truncated N- and O-glycan structures modified by sialylation and fucosylation were identified according to their drift time separated molecular ions and submitted to fragmentation in a narrow mass window. IMS CID MS/MS Analysis The fragmentation spectra generated from the IMS separated precursor ions contain series of fragment ions maintaining the same mobility as their parent ions, and the assignment accuracy can be significantly enhanced. Conclusion According to the specific fragment ion patterns, carbohydrate epitopes described to be involved in pathological processes were assigned. A high potential of this glycomics-based strategy for clinical applications can be presented.

Highlights

A novel approach of ion mobility tandem mass spectrometry (IMS-MS/MS) is applied to analysis of human glycourinome to obtain carbohydrate pattern data of congenital disorders of glycosylation patient
The alteration of glycan patterns related to Congenital disorders of glycosylation (CDG) defects is reflected in the patients’ serum, which can be analyzed for glycosylation patterns of glycoproteins, according to proteomics-based protocols [2]
Mapping and sequencing of monosialylated free and amino acid-linked glycans in the urine of the CDG patient K.L. has been probed in the fraction KLM3 to identify the type of glycans involved, their branching patterns, and sialylation attachment

Summary

Introduction

A novel approach of ion mobility tandem mass spectrometry (IMS-MS/MS) is applied to analysis of human glycourinome to obtain carbohydrate pattern data of congenital disorders of glycosylation patient. Congenital disorders of glycosylation (CDG) are a large family of genetic diseases resulting from defects in the synthesis of glycans and in the attachment of glycans to lipids and proteins These disorders cause a wide range of clinically relevant human diseases with different, sometimes diffuse, clinical pictures. Carbohydrate patterns of CDG patients’ urine were investigated by us using distinct glycomics-based strategies to explore the feasibility of protocols and their potential for unique structure discovery and clinical applications [3,4,5,6]. Components of these highly complex mixtures depict different levels of modifications by sialylation and fucosylation. A high number of intact and truncated N- and O-glycan structures were revealed by high resolution mass spectrometry and correlated to the structures deposited in the

Methods

Results

Conclusion