Exploratory Approach of Serum N-Glycan Profiling by Mass Spectrometry

Introduction Congenital disorders of glycosylation (CDG) are among the inherited metabolic diseases caused by a defect in protein glycosylation. We have used our modified FASP protocol (‘glycoFASP’) to determine the structures of normal and CDG Type 1 patient Nglycans.

Objective Develop a simple FANGS3 protocol to isolate and analyze glycoprotein glycans from human serum. • Apply the glycoFASP method to compare N-glycan profiles between normal control and CDG Type 1 patient.

Methodology [Refer to Poster].

Results glycoFASP-released glycans from normal control and CDG Type 1 patient were analysed using MALDI –TOF/TOF MS are shown in Figure 1. The spectrum shows glycans signal (m/z 1419, 1581 and 1744 ) are not observed from CDG Type 1 patient when compared to normal control spectrum. Normal control also produce non fucosylated (m/z 1501) and fucosylated (m/z 1485,1648 and 1810) complex biantennary, bisecting GlcNAc (m/z 1689, 1851, 2013 and 2175) and sialylated (m/z 1955, 2101 and 2246) glycans. Interestingly, CDG Type 1 spectrum also show non fucosylated (m/z 1501) and fucosylated (m/z 1485,1648 and 1810) complex bi-antennary, sialylated (m/z 1955,2101 and 2246) and bisecting GlcNAc (m/z 1689, 1851 and 2013) glycans lacking (m/z 2175 ). These N-glycans signal are markedly lower compared to normal control.

Conclusion The difference between normal control and CDG Type 1 glycan structures has been demonstrated. • The protocol is less laborious and reduces time in sample preparation before MALDI analysis. • The protocol works efficiently and convenience for low volume of sample.