Journal of Proteomics & Bioinformatics

Journal of Proteomics & Bioinformatics
Open Access

ISSN: 0974-276X


An N-glycosylation Analysis of Human Alpha-2-Macroglobulin Using an Integrated Approach

Zhenxin Lin, Andy Lo, Diane M. Simeone, Mack T. Ruffin and David M. Lubman

Assignment of glycosylation sites and site microheterogeneity is of both biological and clinical significance. Herein, the detailed N-glycosylation pattern of human serum alpha-2-macroglobulin was studied using an integrative approach, including permethylation of N-glycans, collision induced dissociation (CID) and electron transfer dissociation (ETD) of chymotryptic N-glycopeptides, and partial deglycosylation of chymotryptic N-glycopeptides with endo-β-N-acetylglucosaminidase F3 (Endo F3). Three N-glycosylation sites were found to be occupied by four biantennary complex type N-glycans using N-glycan analysis and the ETD/CID method. Endo F3 assisted mass spectrometric analysis yielded five N-glycosylation sites with and without core fucosylation. In total, six out of eight potential N-glycosylation sites were identified using this approach. This integrative approach was performed using only 10 μL of human serum for both N-glycosylation site assignment and site microheterogeneity determination.