A method, which utilizes microwave-assisted partial acid hydrolysis and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOFMS), to elucidate oligosaccharide composition of intact glycoproteins is presented here. Glycoproteins, such as ribonuclease B, avidin, alpha1-acid glycoprotein, and fetuin, are used as model systems to demonstrate this technique. Partial cleavage of oligosaccharides from whole intact glycoproteins with trifluoroacetic acid was observed after a short exposure to microwaves. Due to the high-resolution mass spectra obtained by MALDI-TOFMS from glycoproteins with molecular weights less than 20 kDa, the compositions of oligosaccharides are readily derived for ribonuclease B and avidin. The data agree with the proposed oligosaccharide structures of ribonuclease B (five glycoforms) and avidin (eight glycoforms). Larger glycoproteins such as alpha1-acid glycoprotein (many glycoforms) and fetuin (many glycoforms) exhibited only broad peaks with no glycoform resolution. Nevertheless, this method can be used successfully for analysis of glycoproteins with molecular weights greater than 20 kDa to determine the presence or absence of glycosylation.
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http://dx.doi.org/10.1002/rcm.2096 | DOI Listing |
Anal Chem
January 2025
College of Chemistry, Jilin University, Changchun 130012, China.
Smart-responsive materials have attracted much attention in the enrichment of post-translational modifications of proteins. In this work, for the first time, we developed a smart enrichment strategy (MNPs-l-DOPA/PEI-SP) based on the change in hydrophilic properties of spiropyran under the regulation of light and pH to realize the controllable enrichment and release of intact glycopeptides. The enrichment mechanism and possible binding mechanism were verified by theoretical calculations.
View Article and Find Full Text PDFMedicina (Kaunas)
December 2024
División de Medicina Molecular, Centro de Investigación Biomédica de Occidente (CIBO), Instituto Mexicano del Seguro Social (IMSS), Guadalajara 44340, Jalisco, Mexico.
: Uric acid (UA) and the markers of mineral bone metabolism and inflammation are commonly altered in patients with chronic kidney disease (CKD) and are associated with the risk of cardiovascular complications and death. Studies point to a link between high serum UA and mineral bone homeostasis and inflammation, but controversy remains. The aim of this study was to evaluate the relationship between UA levels and mineral bone metabolism and inflammation biomarkers in a sample of Mexican patients with CKD 3a-5.
View Article and Find Full Text PDFInt J Biol Macromol
December 2024
Institute of Mass Spectrometry, Zhejiang Engineering Research Center of Advanced Mass Spectrometry and Clinical Application, School of Material Science and Chemical Engineering, Ningbo University, Ningbo 315211, China; Zhenhai Institute of Mass Spectrometry, Ningbo 315211, China. Electronic address:
N-glycosylation is crucial in the process of wheat yellow mosaic virus (WYMV) infection, but changes in site-specific N-glycosylation of proteins during WYMV infection have not been well studied. In this study, we employed an intact glycopeptide approach to analyze mock- and WYMV-infected wheat plants. We found that most glycoproteins have N-glycans containing paucimannose or complex/hybrid chains.
View Article and Find Full Text PDFFood Chem
December 2024
Chinese Academy of Inspection and Quarantine, Beijing 100176, People's Republic of China. Electronic address:
Glycoproteins, which are involved in numerous biological functions, are among the most critical functional ingredients in an edible bird's nest (EBN). To gain a comprehensive understanding of the glycoprotein species within EBN, a label-free, site-specific glycoproteomic approach was used to analyze their N-glycoproteins, N-glycopeptides, and N-glycans systematically. A total of 127 N-glycoproteins were identified in EBN, of which 72 were found in house-EBN and 63 in cave-EBN, yielding 4195 and 5649 glycopeptides, respectively.
View Article and Find Full Text PDFJ Neurochem
January 2025
Department of Neurology, Qingdao Municipal Hospital, Qingdao University, Qingdao, China.
The triggering receptor expressed on myeloid cells 2 (TREM2) is a transmembrane protein found in microglia within the brain, and its soluble form (sTREM2) has been shown to reduce amyloid deposition. Whether elevated TREM2-mediated microglial activity decreases the risk of Alzheimer's disease (AD) is unclear. The aim of this study was to assess whether high cerebrospinal fluid (CSF) levels of sTREM2 attenuate the risk of APOE ε4-associated amyloid pathology.
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