Aberrant protein N-glycosylation is one of the hallmarks of malignancy, while its role in oral cancer (OC) progression is still poorly understood making it a perfect biomarker for early-stage cancer. In this work, we describe a MALDI-MS-based N-glycomic analysis with multivariate data analysis approach for exploration and classification of the patients with OC. Various statistical analyses were used to determine differential N-glycome profiles. There were 8 glycan structures significantly increased ( p < 0.05) in all OC-derived microvesicles (MVs). Importantly, the increases in these glycans were significantly greater in the early stage of OC than those in the advanced stage of OC. Additionally, N-glycomic profiles from the serum were also performed, demonstrating a significant change of 11 glycan structures ( p < 0.05). Our data highlighted the effectiveness approach of MALDI-MS-based MV N-glycomic profiling on OC screening, and presented strong potential for further identifying targeted glycoproteomics signatures of the cancer.
Yueyue Li,Yujia Zhai,Bing Fu,Yuanlin He,Ying Feng,Fang Ma,Haojie Lu
Mapping the N-glycome of porcine sperm before and after sperm capacitation is important for understanding the rearrangement of glycoconjugates during capacitation. In this work, we characterized the N-glycome on the membranes of 18 pairs of fresh porcine sperm before capacitation and porcine sperm after capacitation by MALDI-MS (Matrix-assisted laser desorption/ionization-mass spectrometry). A total of 377 N-glycans were detected and a comprehensive N-glycome map of porcine sperm membranes before and after capacitation was generated, which presents the largest N-glycome dataset of porcine sperm cell membranes. Statistical analysis revealed a significantly higher level of high mannose glycosylation and a significantly lower level of fucosylation, galactosylation, and α-2,6-NeuAc after capacitation, which is further verified by flow cytometry and lectin blotting. This research reveals new insights into the relationship between N-glycosylation variations and sperm capacitation, including the underlying mechanisms of the capacitation process.
The structural instability and electronegativity of sialic acids make N-sialoglycan profiling challenging. We compared commonly used preparation strategies, including native, acetohydrazide-based derivatization, and permethylation, in N-glycomics with nMatch, an R-based bioinformatics tool that ensures full coverage of the detected N-glycans using mass spectrometry. We demonstrated that permethylation leads to efficient detection of not only N-sialoglycans but also other N-glycans and, therefore, provides a valuable reference for the selection of the appropriate N-glycan preparation strategy in future studies.
危险品化学品经营许可证（带存储）