Provided herein are methods for identifying new biomarkers for various diseases using proteomics, peptidomics, metabolics, proteoglycomics, glvcomics, mass spectrometry and machine learning. The present disclosure also provides glycopeptides as biomarkers for various diseases such as cancer and autoimmune diseases.

Provided herein are methods of diagnosing or monitoring the treatment of abnormal glycan accumulation or a disorder associated with abnormal glycan accumulation.

Sialic acid recognizing-affinity reagents engineered from the neuraminidase NanB have lectin-like properties and defined specificities for sialic acid.

Compositions and methods for treating ovarian cancer are provided. Methods include combined treatment with chemotherapeutic agents and anti-STn antibodies. Chemotherapy resistant ovarian cancer cells may be reduced. Chemotherapy resistant ovarian cancer cells may include cancer stem cells.

The present disclosure provides, inter alia, genetically encoded recombinant peptide biosensors comprising analyte-binding framework portions and signaling portions, wherein the signaling portions are present within the framework portions at sites or amino acid positions that undergo a conformational change upon interaction of the framework portion with an analyte.

Disclosed is a method of preparing a sample that is suitably used for analysis of a glycoprotein or glycopeptide. A first reaction is performed to modify or remove at least one primary amino group contained in a peptide moiety of a glycopeptide or glycoprotein. Thereafter, a second reaction is performed. The second reaction is a reaction capable of modifying a carboxy group of sialic acid of a sugar chain. After the second reaction, a derivative from 2,3-linked sialic acid a derivative from 2,6-linked sialic acid have different masses. Determination of the presence or absence of sialic acid in the sugar chain of a glycoprotein or glycopeptide and identification of the linkage type of sialic acid can be simply performed by mass spectrometry.

The present invention relates to macrocyclic compounds which are capable of selective binding to a target saccharide (e.g. glucose), making them particularly well suited for use in saccharide sensing applications. The present invention also relates to processes for the preparation of said compounds, to compositions and devices comprising them, and to their use in the detection of a target saccharide.

This disclosure relates to synthetic oligosaccharide subunits of the Pseudomonas exosaccharide Psi and uses thereof, e.g., for epitope mapping of anti-Psl antibodies, for identification of anti-Psl antibodies, and for use as vaccines. In one aspect a synthetic oligosaccharide subunit of a Pseudomonas aeruginosa Psl oligosaccharide is provided, comprising the trisaccharide of formula I.

Provided are a novel method of evaluating an aging condition, a method of presenting information, and a method of screening for a substance capable of improving or preventing an aging condition. A method of evaluating an aging condition of a subject includes the step of: comparing a value from the subject of either of the amount of extracellular vesicles including exosomes in serum, the amount of advanced glycation end products of surface proteins on the extracellular vesicles, or parameters based on the amounts with a correlation criterion, the correlation criterion with the aging condition being pre-determined.

Disclosed is a novel means for accurate qualitative and quantitative analyses for each N-glycosylation site. The method of analyzing N-linked sugar chain(s) of glycoprotein according to the present invention comprises: treating a part of a glycopeptide-containing sample to be analyzed with endo--N-acetylglucosaminidases to cleave off sugar chains while leaving one GlcNAc of the chitobiose core on the Asn at the N-glycosylation site; subjecting the obtained sugar chain-cleaved sample to preliminary liquid chromatography/mass spectrometry; predicting the retention time of the glycopeptide of interest and the mass-to-charge ratio (m/z) of the precursor ion in main analysis based on the results of the preliminary liquid chromatography/mass spectrometry; and carrying out the main analysis. By this method, the binding sites and structures of N-linked sugar chains in a glycoprotein can be analyzed. By using the sugar chain-cleaved sample as an internal standard in the main analysis, quantitative analysis of sugar chains at each glycosylation site also becomes possible.