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Study Results from Korea Research Institute of Standards and Science Update Understanding of Peptides and Proteins (Isotope-Coded...

September 9, 2014



Study Results from Korea Research Institute of Standards and Science Update Understanding of Peptides and Proteins (Isotope-Coded Carbamidomethylation for Quantification of N-Glycoproteins with Online Microbore Hollow Fiber Enzyme ...)

By a News Reporter-Staff News Editor at Life Science Weekly -- Investigators discuss new findings in Proteins. According to news reporting out of Taejon, South Korea, by NewsRx editors, research stated, "This paper introduces a simple, inexpensive, and robust quantitative proteomic method for quantifying N-linked glycoproteins based on isotope-coded carbamidomethylation (iCCM) incorporated into an online microbore hollow fiber enzyme reactor and nanoflow liquid chromatography-tandem mass spectrometry (mHFER-nLC-MS/MS). The iCCM quantitation uses carbamidomethylation (CM; a routine protection of thiol groups before proteolysis) of the Cys residue of proteins with iodoacetamide (IAA) or its isotope (IAA-C-13(2),D-2: 4 Da difference)."

Our news journalists obtained a quote from the research from the Korea Research Institute of Standards and Science, "CM-/iCCM-labeled proteome samples are mixed for proteolysis; then, online enrichment of N-glycopeptides using lectin affinity is carried out in an mHFER before nLC-MS/MS for quantification using multiple reaction monitoring (MRM). Initial evaluation of the iCCM method varying the mixing ratio of CM-/iCCM-labeled bovine serum albumin (BSA) standards yielded successful quantification of 18 peptides with less than 2% variation in the calculated ratio of light/heavy-labeled peptides. The iCCM quantitation with mHFER-nLC-MS/MS was evaluated with three standard glycoproteins (alpha-1-acid glycoproteins, fetuin and transferrin) and then applied to serum glycoproteins from liver cancer patients and controls, resulting in successful quantification of 73 N-glycopeptides (from 49 N-glycoproteins), among which 19 N-glycopeptides from 14 N-glycoproteins showed more than a 2.5-fold aberrant change in liver cancer patients' sera compared with the pooled control. Although iCCM quantitation with mHFER-nLC-MS/MS applies only to glycopeptides with Cys residue, the method can offer several advantages over other labeling methods when applied to targeted glycoproteins: The iCCM method does not require an additional labeling reaction under special conditions nor complicated procedures to purify labeled products using additional columns. Isotope labeling at the protein level can minimize potential uncertainty originating from unequal efficiencies in protein digestion in separate vials and retrieval of each labeled peptide when labeling takes place at the peptide level."

According to the news editors, the research concluded: "In addition, the labeling reagents for the iCCM method are readily obtained at a reasonable cost, which can make protein quantification easily accessible."

For more information on this research see: Isotope-Coded Carbamidomethylation for Quantification of N-Glycoproteins with Online Microbore Hollow Fiber Enzyme Reactor-Nanoflow Liquid Chromatography-Tandem Mass Spectrometry. Analytical Chemistry, 2014;86(15):7650-7657. Analytical Chemistry can be contacted at: Amer Chemical Soc, 1155 16TH St, NW, Washington, DC 20036, USA. (American Chemical Society - www.acs.org; Analytical Chemistry - www.pubs.acs.org/journal/ancham)

Our news journalists report that additional information may be obtained by contacting J.Y. Kim, Korea Res Inst Stand & Sci, Div Metrol Qual Life, Center Bioanal, Taejon 305340, South Korea. Additional authors for this research include D. Oh, S.K. Kim, D. Kang and M.H. Moon (see also Proteins).

Keywords for this news article include: Taejon, South Korea, Asia, Enzymes and Coenzymes, Glycoconjugates, Glycopeptides, Glycoproteins

Our reports deliver fact-based news of research and discoveries from around the world. Copyright 2014, NewsRx LLC


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Source: Life Science Weekly


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