The Experts below are selected from a list of 32310 Experts worldwide ranked by ideXlab platform
Matthew M. Champion - One of the best experts on this subject based on the ideXlab platform.
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quantitative Multiple Reaction Monitoring of peptide abundance introduced via a capillary zone electrophoresis electrospray interface
Analytical Chemistry, 2012Co-Authors: Yihan Li, Roza Wojcik, Norman J. Dovichi, Matthew M. ChampionAbstract:We demonstrate the use of capillary zone electrophoresis with an electrokinetic sheath-flow electrospray interface coupled to a triple-quadrupole mass spectrometer for the accurate and precise quantification of Leu-enkephalin in a complex mixture using Multiple-Reaction Monitoring (MRM). Assay time is <6 min, with no re-equilibration required between runs. A standard curve of Leu-enkephalin was performed in the presence of a background tryptic digest of bovine albumin. We demonstrate reasonably reproducible peak heights (21% relative standard deviation), retention times (better than 1% relative standard deviation), and robust electrospray quality. Our limit of detection (3σ) was 60 pM, which corresponds to the injection of 335 zmol of peptide. This is a 10–20-fold improvement in mass sensitivity than we have obtained by nano HPLC/MRM and substantially better than reported for LC/MS/MS. Further quantification was performed in the presence of stable-isotope-labeled versions of the peptides; under these cond...
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Quantitative Multiple Reaction Monitoring of Peptide Abundance Introduced via a Capillary Zone Electrophoresis–Electrospray Interface
Analytical Chemistry, 2012Co-Authors: Yihan Li, Roza Wojcik, Norman J. Dovichi, Matthew M. ChampionAbstract:We demonstrate the use of capillary zone electrophoresis with an electrokinetic sheath-flow electrospray interface coupled to a triple-quadrupole mass spectrometer for the accurate and precise quantification of Leu-enkephalin in a complex mixture using Multiple-Reaction Monitoring (MRM). Assay time is
Yihan Li - One of the best experts on this subject based on the ideXlab platform.
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quantitative Multiple Reaction Monitoring of peptide abundance introduced via a capillary zone electrophoresis electrospray interface
Analytical Chemistry, 2012Co-Authors: Yihan Li, Roza Wojcik, Norman J. Dovichi, Matthew M. ChampionAbstract:We demonstrate the use of capillary zone electrophoresis with an electrokinetic sheath-flow electrospray interface coupled to a triple-quadrupole mass spectrometer for the accurate and precise quantification of Leu-enkephalin in a complex mixture using Multiple-Reaction Monitoring (MRM). Assay time is <6 min, with no re-equilibration required between runs. A standard curve of Leu-enkephalin was performed in the presence of a background tryptic digest of bovine albumin. We demonstrate reasonably reproducible peak heights (21% relative standard deviation), retention times (better than 1% relative standard deviation), and robust electrospray quality. Our limit of detection (3σ) was 60 pM, which corresponds to the injection of 335 zmol of peptide. This is a 10–20-fold improvement in mass sensitivity than we have obtained by nano HPLC/MRM and substantially better than reported for LC/MS/MS. Further quantification was performed in the presence of stable-isotope-labeled versions of the peptides; under these cond...
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Quantitative Multiple Reaction Monitoring of Peptide Abundance Introduced via a Capillary Zone Electrophoresis–Electrospray Interface
Analytical Chemistry, 2012Co-Authors: Yihan Li, Roza Wojcik, Norman J. Dovichi, Matthew M. ChampionAbstract:We demonstrate the use of capillary zone electrophoresis with an electrokinetic sheath-flow electrospray interface coupled to a triple-quadrupole mass spectrometer for the accurate and precise quantification of Leu-enkephalin in a complex mixture using Multiple-Reaction Monitoring (MRM). Assay time is
Renee L Ruhaak - One of the best experts on this subject based on the ideXlab platform.
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Multiple Reaction Monitoring for the quantitation of serum protein glycosylation profiles application to ovarian cancer
Journal of Proteome Research, 2018Co-Authors: Suzanne Miyamoto, Carlito B Lebrilla, Qiuting Hong, Renee L Ruhaak, Carol Stroble, Sandra L Taylor, Gary S LeiserowitzAbstract:Protein glycosylation fingerprints are widely recognized as potential markers for disease states, and indeed differential glycosylation has been identified in Multiple types of autoimmune diseases and several types of cancer. However, releasing the glycans leave the glycoproteins unknown; therefore, there exists a need for high-throughput methods that allow quantification of site- and protein-specific glycosylation patterns from complex biological mixtures. In this study, a targeted Multiple Reaction Monitoring (MRM)-based method for the protein- and site-specific quantitation involving serum proteins immunoglobulins A, G and M, alpha-1-antitrypsin, transferrin, alpha-2-macroglobulin, haptoglobin, alpha-1-acid glycoprotein and complement C3 was developed. The method is based on tryptic digestion of serum glycoproteins, followed by immediate reverse phase UPLC-QQQ-MS analysis of glycopeptides. To quantitate protein glycosylation independent of the protein serum concentration, a nonglycosylated peptide was ...
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label free absolute quantitation of oligosaccharides using Multiple Reaction Monitoring
Analytical Chemistry, 2014Co-Authors: Qiuting Hong, Renee L Ruhaak, Sarah M Totten, Jennifer T Smilowitz, Bruce J German, Carlito B LebrillaAbstract:An absolute quantitation method for measuring free human milk oligosaccharides (HMOs) in milk samples was developed using Multiple Reaction Monitoring (MRM). To obtain the best sensitivity, the instrument conditions were optimized to reduce the source and postsource fragmentation prior to the quadrupole transmission. Fragmentation spectra of HMOs using collision-induced dissociation were studied to obtain the best characteristic fragments. At least two MRM transitions were used to quantify and identify each structure in the same run. The fragment ions corresponded to the production of singly charged mono-, di-, and trisaccharide fragments. The sensitivity and accuracy of the quantitation using MRM were determined, with the detection limit in the femtomole level and the calibration range spanning over 5 orders of magnitude. Seven commercial HMO standards were used to create calibration curves and were used to determine a universal response for all HMOs. The universal response factor was used to estimate ab...
Bin Hu - One of the best experts on this subject based on the ideXlab platform.
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global detection and semi quantification of fritillaria alkaloids in fritillariae ussuriensis bulbus by a non targeted Multiple Reaction Monitoring approach
IEEE Journal of Solid-state Circuits, 2016Co-Authors: Li Wang, Ping Li, Sibao Chen, Puikin So, Bin HuAbstract:: Methods based on triple quadrupole tandem mass spectrometry have been widely used and reported as highly selective and sensitive methods for quantifying substances of herbal medicines. However, most of them were limited to targeted components, due to the difficulties to optimize the Multiple Reaction Monitoring transitions without authentic standards. This study proposed a novel strategy for non-targeted optimization of Multiple Reaction Monitoring method based on the diagnostic ion guided family classifications, tandem mass spectrometry database establishment, and transitions and collision energy screening. Applying this strategy, 59 Fritillaria alkaloids in Fritillariae Ussuriensis Bulbus have been classified, and 51 of these Fritillaria alkaloids were successfully detected by the optimal Multiple Reaction Monitoring method. For semi-quantification, the easy-to-obtain Fritillaria alkaloids of each type, such as verticinone for cevanine type and peimisine for jervine type, were used as the reference standards to calibrate the other Fritillaria alkaloids in the same type. The method was demonstrated a good linearity (R(2) > 0.998) with satisfactory accuracy and precision, and the lower limits of quantification of verticinone and peimisine were estimated to be 0.076 and 0.216 pg, respectively. In addition, the results suggested that the proposed strategy might obtained high quality metabolomics data in discrimination of Fritillaria unibracteata and Fritillaria ussuriensis.
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Global detection and semi‐quantification of Fritillaria alkaloids in Fritillariae Ussuriensis Bulbus by a non‐targeted Multiple Reaction Monitoring approach
IEEE Journal of Solid-state Circuits, 2015Co-Authors: Li Wang, Ping Li, Sibao Chen, Puikin So, Bin HuAbstract:: Methods based on triple quadrupole tandem mass spectrometry have been widely used and reported as highly selective and sensitive methods for quantifying substances of herbal medicines. However, most of them were limited to targeted components, due to the difficulties to optimize the Multiple Reaction Monitoring transitions without authentic standards. This study proposed a novel strategy for non-targeted optimization of Multiple Reaction Monitoring method based on the diagnostic ion guided family classifications, tandem mass spectrometry database establishment, and transitions and collision energy screening. Applying this strategy, 59 Fritillaria alkaloids in Fritillariae Ussuriensis Bulbus have been classified, and 51 of these Fritillaria alkaloids were successfully detected by the optimal Multiple Reaction Monitoring method. For semi-quantification, the easy-to-obtain Fritillaria alkaloids of each type, such as verticinone for cevanine type and peimisine for jervine type, were used as the reference standards to calibrate the other Fritillaria alkaloids in the same type. The method was demonstrated a good linearity (R(2) > 0.998) with satisfactory accuracy and precision, and the lower limits of quantification of verticinone and peimisine were estimated to be 0.076 and 0.216 pg, respectively. In addition, the results suggested that the proposed strategy might obtained high quality metabolomics data in discrimination of Fritillaria unibracteata and Fritillaria ussuriensis.
D C Liebler - One of the best experts on this subject based on the ideXlab platform.
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comparison of protein immunoprecipitation Multiple Reaction Monitoring with elisa for assay of biomarker candidates in plasma
Journal of Proteome Research, 2013Co-Authors: William E Alborn, Robbert J C Slebos, D C LieblerAbstract:Quantitative analysis of protein biomarkers in plasma is typically done by ELISA, but this method is limited by the availability of high-quality antibodies. An alternative approach is protein immunoprecipitation combined with Multiple Reaction Monitoring mass spectrometry (IP-MRM). We compared IP-MRM to ELISA for the analysis of six colon cancer biomarker candidates (metalloproteinase inhibitor 1 (TIMP1), cartilage oligomeric matrix protein (COMP), thrombospondin-2 (THBS2), endoglin (ENG), mesothelin (MSLN) and matrix metalloproteinase-9 (MMP9)) in plasma from colon cancer patients and noncancer controls. Proteins were analyzed by Multiplex immunoprecipitation from plasma with the ELISA capture antibodies, further purified by SDS-PAGE, digested and analyzed by stable isotope dilution MRM. IP-MRM provided linear responses (r = 0.978–0.995) between 10 and 640 ng/mL for the target proteins spiked into a “mock plasma” matrix consisting of 60 mg/mL bovine serum albumin. Measurement variation (coefficient of va...
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precision of Multiple Reaction Monitoring mass spectrometry analysis of formalin fixed paraffin embedded tissue
Journal of Proteome Research, 2012Co-Authors: Robert W Sprung, Misti A Martinez, Kristen L Carpenter, Mary Kay Washington, Carlos L Arteaga, Melinda E Sanders, D C LieblerAbstract:We compared the reproducibility of Multiple Reaction Monitoring (MRM) mass spectrometry-based peptide quantitation in tryptic digests from formalin-fixed, paraffin-embedded (FFPE) and frozen clear cell renal cell carcinoma tissues. The analyses targeted a candidate set of 114 peptides previously identified in shotgun proteomic analyses, of which 104 were detectable in FFPE and frozen tissue. Although signal intensities for MRM of peptides from FFPE tissue were on average 66% of those in frozen tissue, median coefficients of variation (CV) for measurements in FFPE and frozen tissues were nearly identical (18–20%). Measurements of lysine C-terminal peptides and arginine C-terminal peptides from FFPE tissue were similarly reproducible (19.5% and 18.3% median CV, respectively). We further evaluated the precision of MRM-based quantitation by analysis of peptides from the Her2 receptor in FFPE and frozen tissues from a Her2 overexpressing mouse xenograft model of breast cancer and in human FFPE breast cancer sp...
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methods for peptide and protein quantitation by liquid chromatography Multiple Reaction Monitoring mass spectrometry
Molecular & Cellular Proteomics, 2011Co-Authors: Haixia Zhang, Lisa J Zimmerman, Robbert J C Slebos, Jamshedur Rahman, Takefume Kikuchi, Pierre P Massion, David P Carbone, Dean Billheimer, D C LieblerAbstract:Liquid chromatography-Multiple Reaction Monitoring mass spectrometry of peptides using stable isotope dilution (SID) provides a powerful tool for targeted protein quantitation. However, the high cost of labeled peptide standards for SID poses an obstacle to Multiple Reaction Monitoring studies. We compared SID to a labeled reference peptide (LRP) method, which uses a single labeled peptide as a reference standard for all measured peptides, and a label-free (LF) approach, in which quantitation is based on analysis of un-normalized peak areas for detected MRM transitions. We analyzed peptides from the Escherichia coli proteins alkaline phosphatase and β-galactosidase spiked into lysates from human colon adenocarcinoma RKO cells. We also analyzed liquid chromatography-Multiple Reaction Monitoring mass spectrometry data from a recently published interlaboratory study by the National Cancer Institute Clinical Proteomic Technology Assessment for Cancer network (Addona et al. (2009) Nat. Biotechnol. 27: 633–641), in which unlabeled and isotopically labeled synthetic peptides or their corresponding proteins were spiked into human plasma. SID displayed the highest correlation coefficients and lowest coefficient of variation in regression analyses of both peptide and protein spike studies. In protein spike experiments, median coefficient of variation values were about 10% for SID and 20–30% for LRP and LF methods. Power calculations indicated that differences in measurement error between the methods have much less impact on measured protein expression differences than biological variation. All three methods detected significant (p < 0.05) differential expression of three endogenous proteins in a test set of 10 pairs of human lung tumor and control tissues. Further, the LRP and LF methods both detected significant differences (p < 0.05) in levels of seven biomarker candidates between tumors and controls in the same set of lung tissue samples. The data indicate that the LRP and LF methods provide cost-effective alternatives to SID for many quantitative liquid chromatography-Multiple Reaction Monitoring mass spectrometry applications.
