The present disclosure provides methods, compositions, and kits for the rapid release, labeling, and detection of O-glycans present on a glycoconjugate, such as a glycoprotein, glycopeptide, peptidoglycan, or proteoglycan of interest. The compositions and methods allow the released O-glycans to be subjected to high-throughput analysis.

Methods for performing procedures on single analytes at single-analyte resolution are disclosed. The methods utilize an iterative approach to performing a sequence of steps during a single-analyte process. Control of the single-analyte process is achieved by implementing actions during each iteration based upon one or more determined process metrics. Systems are also detailed for implementing the disclosed methods at single-analyte resolution.

A method for determining in a sample, by mass spectrometry, the amount of one or more analytes selected from the group consisting of 12,13-DiHOME, 3-hydroxybutyrate (BHBA), 3-hydroxyoctanoate, 3-methylglutarylcarnitine, 3-ureidopropionate, 7-alpha-hydroxy-4-cholesten-3-one (7-Hoca), citrate, fucose, fumarate, gamma-tocopherol, glutamate, glutarate, glycerol, glycochenodeoxycholate, glycocholate, hypoxanthine, maleate, malonate, mannose, orotate, 2,3-pyrdinedicarboxylate, ribose, serine, taurine, taurochenodeoxycholate, taurocholate, palmitoleate, linolenate, xanthine, xylitol, and combinations thereof is described. The method comprises subjecting the sample to an ionization source under conditions suitable to produce one or more ions detectable by mass spectrometry from each of the one or more analytes; measuring, by mass spectrometry, the amount of the one or more ions from each of the one or more analytes; and using the measured amount to determine the amount of each of the one or more analytes in the sample.

The present invention generally provides, in various embodiments, improved methods of analyzing proteins utilizing liquid chromatography and tandem mass spectroscopy (LC-MS/MS), such as by multiplexing samples and using data-independent acquisition.

The present invention relates to an amphiphilic compound having a dendronic hydrophobic group, a method for preparing the same, and a method for extraction, solubilization, stabilization, or crystallization of a membrane protein by using the same. The use of the compound according to the present invention leads to an excellent membrane protein solubilization effect and a stable storage of a membrane protein in an aqueous solution for a long time, and thus can be utilized for functional analysis and structural analysis of the membrane protein. Especially, the amphiphilic compound having a dendronic hydrophobic group showed very remarkable characteristics in the visualization of protein composites through an electronic microscope. The membrane protein structural and functional analysis is one of the fields of greatest interest in current biology and chemistry, and more than half of the new drugs that are currently being developed are targeted at membrane proteins, and thus the amphiphilic compound of the present invention can be applied to membrane protein structure studies closely related to the development of new drugs.

A method for rapid detection of dry eye syndrome includes collecting a first tear fluid from healthy participant and a second tear fluid from patient with eye dryness; isolating EV samples from the first tear fluid; acquiring a first fingerprint diagram of proteomes of the EV samples from the first tear fluid, the first fingerprint diagram comprises a plurality of first discriminant peaks; isolating EV samples from the second tear fluid; acquiring a second fingerprint diagram of proteomes of the EV samples from the second tear fluid, the second fingerprint diagram comprises a plurality of second discriminant peaks; and comparing the first discriminant peaks and the second discriminant peaks to determine whether the patient has the DES. This is a fast and precise method for detecting the DES of the participant.

Kits and methods of using the kits for analyzing macromolecules, including peptides, polypeptides, and proteins, employing nucleic acid encoding are disclosed. The sample analysis kits employ nucleic acid encoding and/or nucleic acid recording of a molecular interaction and/or reaction, such as recognition events (e.g., between an antigen and an antibody, between a modified terminal amino acid residue, or between a small molecule or peptide therapeutic and a target, etc.). Additional barcoding reagents, such as those for cycle-specific barcoding (e.g., “clocking”), compartment barcoding, combinatorial barcoding, spatial barcoding, or any combination thereof, may be included in the kits. The sample may comprise macromolecules, including peptides, polypeptides, and proteins, and the recording may generate molecular interaction and/or reaction information, and/or polypeptide sequence information. The kits may be used in high-throughput, multiplexed, and/or automated analysis, and are suitable for analysis of a proteome or subset thereof.

The invention relates to a new method of determining the presence, absence, number or position(s) of one or more post-translational modifications in a peptide, polypeptide or protein. The invention uses transmembrane pores.

The present invention relates to a method for identifying endogenous first responder protein-cysteines. Methods for screening candidate compounds suitable for regulating NF-kB signaling and the DNA damage response pathway are also disclosed.

A method for analyzing macromolecules, including peptides, polypeptides, and proteins, employing nucleic acid encoding is disclosed.