Determination of specific glycobiomarkers in alpha-mannosidosis patients by NMR and mass spectrometry

Primárne karty

ISBN: ISBN 978-80-972360-7-6

Determination of specific glycobiomarkers in alpha-mannosidosis patients by NMR and mass spectrometry

Zuzana Pakanová1 Mária Matulová1 Marek Nemčovič1 Filip Pančík1 Filip Květoň1 Iveta Uhliariková1 Anna Šalingová2 Anna Hlavatá3 Ján Mucha1 Peter Baráth1
1Institute of Chemistry, Slovak Academy of Sciences, Bratislava
2National Institute of Children´s Diseases, Department of Laboratory Medicine, Bratislava
3Comenius University, Faculty of Medicine and National Institute of Children´s Diseases, Department of Paediatrics, Bratislava

Alpha-mannosidosis is a progressive lysosomal storage disorder, firstly described in 1967[1]. It is caused by a partial or complete deficiency of alpha-mannosidose, enzyme playing an essential role in oligosaccharide and glycoprotein degradation. Mannose-rich oligosaccharides are accumulated in lysosomes of all tissues, resulting in impaired cellular function and apoptosis [2]. Due to the variability of clinical manifestation and multisystematic involvement, its definitive diagnostics may be challenging. MALDI TOF/TOF mass spectrometric analyses of permethylated oligosaccharides from urine of alpha-mannosidosis patients revealed characteristic set of specific mannose-based glycobiomarkers, compiled from Man2GlcNAc1 (m/z 722.3) up to Man8GlcNAc1 (m/z 1947.0). In 1H NMR spectra, characteristic signals of mannose units, originated from mannose in various linkages and locations in these oligosaccharides, as well as α,βGlcNAc from reducing ends were identified. Despite of non-quantitative nature of MALDI TOF/TOF analysis, 1H NMR was used for an overall quantification of mannose oligosaccharides. It is based on the integration of the signal, representing the core 1,3,6-linked βMan unit bound to the reducing end GlcNAc unit. Significantly increased intensities of 1,3-linked αMan signals in 1H NMR spectra confirmed results from mass spectrometry, suggesting Man2GlcNAc1 as the most abundant structure found in urine of alpha-mannosidosis patients. Presented methods were developed to become the basis for a precise monitoring of therapy efficacy in the future.


This work was supported by Ministry of Health of the Slovak Republic under the project registration number 2019/7-CHÚSAV-4, VEGA 2/0130/18, and APVV-18-0336. This contribution is the result of the implementation of the “Technical infrastructure for biomedical research” project, ITMS 26230120008, which was supported by the Research & Development Operational Programme and funded by the ERDF.


[1] Malm D, Nilssen O (2008). Alpha-mannosidosis. Orphanet J Rare Dis.3(1):21.
[2] Beck M, Olsen KJ, Wraith JE et al. (2013). Natural history of alpha-mannosidosis: a longitudinal study. Orphanet J Rare Dis.8:88.