Dataset Information

In-depth site-specific O-glycosylation analysis of glycoproteins and endogenous peptides in cerebrospinal fluid (CSF) from healthy individual mild cognitive impairment (MCI) and Alzheimer disease (AD) patients

ABSTRACT: Site-specific O-glycoproteome mapping in complex biological system provides molecular basis for understanding the structure-function relationships of glycoproteins and their roles in physiological and pathological processes. Previous O-glycoproteome analysis in cerebrospinal fluid (CSF) focused on sialylated glycoforms, and many CSF glycoproteins have not been characterized comprehensively with respect to their O-glycosylation. In order to provide an unbiased O-glycosylation profiling, we have developed an integrated strategy combining universal boronic acid enrichment, high-pH fractionation, and electron-transfer and higher-energy collision dissociation (EThcD) for improved intact O-glycopeptide analysis. This strategy was applied to analyze O-glycoproteome in CSF, leading to identifications of 308 O-glycopeptides from 110 O-glycoproteins, covering both sialylated and non-sialylated glycoforms. To our knowledge, this is the largest number of O-glycoproteins and O-glycosites reported for CSF so far, including 154 novel O-glycosites. Due to a lack of peptidomics workflow that could incorporate glycosylation analysis, the glycosylation state of CSF endogenous peptides has not been comprehensively studied. Here, we developed a peptidomics workflow that utilizes the EThcD fragmentation and a three-step database searching strategy, allowing both N-glycosylation and O-glycosylation, as well as other common peptide PTMs, to be analyzed at the same time. Interestingly, among the 1492 endogenous peptides identified, 95 of them were O-glycosylated and only 1 N-glycosylated peptide was found, indicating CSF endogenous peptides were preferentially O-glycosylated. By referring to human neuropeptide database, 15 of them were actually O-glycosylated neuropeptides deriving from ProSAAS and secretogranin-1. O-glycoproteome and endogenous peptidome PTMs analysis were also conducted in MCI and AD patients to give a landscape picture of glycosylation in these disease states. The results showed that a decreased fucosylation trend was found in MCI and AD, suggesting its potential relation to the progression of AD.

INSTRUMENT(S): Orbitrap Fusion Lumos

ORGANISM(S): Homo Sapiens (ncbitaxon:9606)

SUBMITTER: Lingjun Li

PROVIDER: MSV000087160 | MassIVE | Mon Apr 05 19:27:00 BST 2021

SECONDARY ACCESSION(S): PXD025162

REPOSITORIES: MassIVE

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In-Depth Site-Specific O-Glycosylation Analysis of Glycoproteins and Endogenous Peptides in Cerebrospinal Fluid (CSF) from Healthy Individuals, Mild Cognitive Impairment (MCI), and Alzheimer's Disease (AD) Patients.

Chen Zhengwei Z Wang Danqing D Yu Qing Q Johnson Jillian J Shipman Richard R Zhong Xiaofang X Huang Junfeng J Yu Qinying Q Zetterberg Henrik H Asthana Sanjay S Carlsson Cynthia C Okonkwo Ozioma O Li Lingjun L

ACS chemical biology 20211229 11

Site-specific O-glycoproteome mapping in complex biological systems provides a molecular basis for understanding the structure-function relationships of glycoproteins and their roles in physiological and pathological processes. Previous O-glycoproteome analysis in cerebrospinal fluid (CSF) focused on sialylated glycoforms, while missing information on other glycosylation types. In order to achieve an unbiased O-glycosylation profile, we developed an integrated strategy combining universal boroni ...[more]

PMID: 34964596

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