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Characterization of Phase I and Glucuronide Phase II Metabolites of 17 Mycotoxins Using Liquid Chromatography-High-Resolution Mass Spectrometry

Author(s): Slobodchikova I; Sivakumar R; Rahman MS; Vuckovic D;

Routine mycotoxin biomonitoring methods do not include many mycotoxin phase I and phase II metabolites, which may significantly underestimate mycotoxin exposure especially for heavily metabolized mycotoxins. Additional research efforts are also needed to me...

Article GUID: 31344861
Evaluation of D10-Leu metabolic labeling coupled with MALDI-MS analysis in studying the response of the yeast proteome to H2O2 challenge

Author(s): Jiang H; English AM;

An efficient D10-Leu metabolic-labeling method combined with isotope-ratio quantitation by MALDI-TOF MS was used to probe the response of the yeast proteome to H2O2. Control cultures correct for effects not associated with H2O2 challenge. A stress-response ...

Article GUID: 17022625
Reduction and S-nitrosation of the neuropeptide oxytocin: implications for its biological function

Author(s): Roy JF; Chrétien MN; Woodside B; English AM;

Oxytocin (OT; Cys-Tyr-Ile-Gln-Asn-Cys-Pro-leu-Gly), a posterior pituitary peptide hormone, is characterized by a Cys1-Cys6 disulfide bond in its stable, isolated state. This paper describes a simple, one-step method for the production of OT in its reduced, ...

Article GUID: 17692543
Human blood cell levels of 5-hydroxymethylcytosine (5hmC) decline with age, partly related to acquired mutations in TET2

Author(s): Buscarlet M; Tessier A; Provost S; Mollica L; Busque L;

Epigenetic alteration may play a role in age-associated dysfunction of stem cells and predispose to the development of hematological cancers. We analyzed global levels of hematopoietic 5-hydroxymethylcytosine (5hmC) and 5-methylcytosine (5mC) in a cross-sec...

Article GUID: 27475703
Title:Reduction and S-nitrosation of the neuropeptide oxytocin: implications for its biological function
Authors:Roy JF,  Chrétien MN,  Woodside B,  English AM, 
Link:https://pubmed.ncbi.nlm.nih.gov/17692543/
DOI:10.1016/j.niox.2007.06.005
Category:Nitric Oxide
PMID:17692543
Dept Affiliation: CBAMS
1 Department of Chemistry and Biochemistry, Centre for Biological Applications of Mass Spectrometry, Concordia University, 7141 Sherbrooke Street W., Montreal, Que., Canada.

Description:

Oxytocin (OT; Cys-Tyr-Ile-Gln-Asn-Cys-Pro-leu-Gly), a posterior pituitary peptide hormone, is characterized by a Cys1-Cys6 disulfide bond in its stable, isolated state. This paper describes a simple, one-step method for the production of OT in its reduced, dithiol form (OT dithiol), free of reducing agent. The effects of temperature, pH, and metal-ion chelators on the autoxidation of OT dithiol were examined to establish if this form is likely to persist under biological conditions. It was found that OT dithiol has a half-life of 1.8h with respect to reformation of OT disulfide at 37 degrees C and pH 6.9 in the presence of the copper chelators, DTPA and neocuproine. S-Nitrosation of OT dithiol by acidified nitrite at pH 3.0 was examined by absorption spectroscopy and HPLC-UV-MS, which revealed that both singly and doubly S-nitrosated OT are formed. These results suggest novel chemical aspects to OT signaling, the biological implications of which are discussed here.