Embodiments of the disclosure include means of identifying and quantifying particular metabolite-based biomarkers for diagnosis and prognosis of prostate cancer in African American men, including at least Methionine, Homocysteine, Glutamic acid, Ornithine, and/or Inosine, and, in some cases, also N-Acetyl Aspartate, Glutamine, Sarcosine, Succinate, and/or Malate.

The present disclosure provides methods for treating homocystinuria or elevated homocysteine levels in subjects, including methods of improving cognitive function and ameliorating skeletal fragility, and methods of stratifying patient populations to determine disease progression or severity and/or to determine treatment regimens. In some embodiments, the methods of improving cognitive function in a subject having elevated total plasma homocysteine (tHcy) levels further comprise providing a cognitive or behavioral intervention.

A biothiol-activatable composition is disclosed that is configured to dissociate in the presence of a concentration of biomolecules that are excreted normally by a liver of a living subject comprising a noble metal nanoparticle, a reporter molecule, a linker molecule that is conjugated to the noble metal nanoparticle and to the reporter molecule, but displaceable in the presence of the biomolecules, and wherein the reporter molecule is released in the presence of the biomolecules. The noble nanoparticle is preferably a gold nanoparticle; the reporter molecule preferably comprises at least one of a fluorescent dye molecule, a radioactive molecule or an MRI agent and the linker molecule is preferably a thiol molecule displaceable by biothiols in the liver. In another aspect, the reporter molecule dissociates from the composition in the presence of a concentration of glutathione similar to what is found in liver sinusoids of a normally functioning liver.

Purine-derived covalent probes (e.g., halo or di-halo-substituted purine based covalent probes) and related ligands are described. The compounds can be used to identify reactive nucleophilic amino acid residues, such as reactive cysteine residues, in proteins and to modify the activity of proteins with reactive nucleophilic amino acid residues (e.g., reactive cysteine residues) via the formation of protein adducts comprising the ligands Modified proteins prepared from the probes and ligands are also described.

There is provided method of profiling protein tyrosine phosphorylation of a sample, the method comprising: contacting the sample with an SH2 Superbinder in order to bind pTyr-including peptides contained in the sample with the SH2 Superbinder; isolating the bound pTyr-including peptides from the sample; and identifying the isolated pTyr-including peptides.

The present disclosure relates to a composition for screening an intestinal environment-improving material and a screening method using the composition, and according to the composition and the method of the present disclosure, it is possible to provide an effective analysis method for screening a microbiota-improving candidate material in a personalized manner by providing a method for verifying personalized probiotics, prebiotics, foods, health functional foods and drugs under in vitro conditions based on microbiota and microbiota metabolites.

A method for examining a biological fluid whereby quantitative examinations of various minerals and methionine, one of essential amino acids, contained in a biological fluid can be conducted simply, accurately, and at a low price is provided, wherein using an X-ray fluorescence analysis device, content ratios of minerals contained in a biological fluid of a subject which can be taken by the subject to sulfur originating in methionine contained therein are measured, contents of the sulfur and the minerals contained therein are calculated using the measured content ratios and calibration curves previously prepared by X-ray fluorescence analysis of standard solutions of the sulfur and the minerals, and a content of the methionine contained therein is calculated on the basis of the calculated content of the sulfur.

The present invention, in some aspects, relates to systems and methods for determining oxidized proteins, including glutathionylated proteins such as S-glutathionylated proteins. The systems and methods of the invention can be used in vitro (e.g., in cell or tissue culture) or in vivo, for example, to diagnose a person having an oxidative stress condition. For instance, in some cases, the invention can be used to spatially determine the location and/or concentration of oxidized proteins within cells and/or tissues (e.g., through visual detection). In one set of embodiments, a glutathionylated or otherwise oxidized moiety on a protein may be reacted with a detection entity, which may be, for example, fluorescent, radioactive, electron-dense, able to bind to a signaling entity or a binding partner in order to produce a signal, etc. As a specific example, a glutathionylated moiety on a glutathionylated protein may be reacted with an alkylating agent to form an alkylthio moiety; the alkylthio moiety may include a detection entity or otherwise be able to interact with a signaling entity. In some embodiments, other moieties on the protein may be altered or blocked before reaction of the protein with the detection entity. Such moieties on the protein may be, for instance, non-oxidized or non-glutathionylated moieties able to react with the detection entity. As a particular example, in a protein containing a glutathionylated moiety and non-glutathionylated thiol moieties, the thiol moieties may first be altered or blocked prior to reaction of the protein with the detection entity. Also provided in certain aspects of the present invention are kits for determining oxidized proteins, which may include components such as detection entities, alkylating agents, blocking agents, reducing agents, signaling entities, binding partners, antibodies, instructions, and the like.

The present invention relates to a method of improving the quality of therapeutic cells by real-time glutathione monitoring.

A method of stabilising a biological sample including glutathione (GSH) and glutathione disulfide (GSSG), including a) providing the biological sample having GSH and GSSG; b) contacting GSH and GSSG of the sample with a maleimide to obtain maleimide-alkylated GSH; c) separating excess maleimide from maleimide-alkylated GSH and GSSG; d) contacting maleimide-alkylated GSH and GSSG with a reducing agent such as TCEP under conditions which allow reduction of GSSG by the reducing agent such as TCEP to obtain further GSH; and e) contacting maleimide-alkylated GSH and GSH with a heavy isotopologue of the maleimide to obtain a heavy isotopologue of the maleimide-alkylated GSH. A stabilised biological sample is provide containing maleimide-alkylated GSH and a heavy isotopologue thereof, as well as a mass-spectrometric method for quantifying maleimide-alkylated GSH and a heavy isotopologue thereof in a sample and a kit for stabilising a biological sample including GSH and GSSG for mass spectrometric analysis.