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Abstract
The apolipoproteins are well known for their roles in both health and disease, as components of plasma lipoprotein particles, such as high-density lipoprotein (HDL), low-density lipoprotein (LDL), very-low-density lipoprotein (VLDL), chylomicrons, and metabolic, vascular- and inflammation-related disorders, such as cardiovascular disease, atherosclerosis, metabolic syndrome, and diabetes. Increasingly, their roles in neurovascular and neurodegenerative disorders are also being elucidated. They play major roles in lipid and cholesterol transport between blood and organs and are, therefore, critical to maintenance and homeostasis of the lipidome, with apolipoprotein-lipid interactions, including cholesterol, fatty acids, triglycerides, phospholipids, and isoprostanes. Further, they have important pleiotropic roles related to aging and longevity, which are largely managed through their many structural variants, including multiple isoforms, and a diversity of post-translational modifications. Consequently, tools for the characterization and accurate quantification of apolipoproteins, including their diverse array of variant forms, are required to understand their salutary and disease related roles. In this chapter we outline three distinct quantitative approaches suitable for targeting apolipoproteins: (1) multiplex immunoassays, (2) mass spectrometric immunoassay, and (3) multiple reaction monitoring, mass spectrometric quantification. We also discuss management of pre-analytical and experimental design variables.
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Kiseleva OI, Lisitsa AV, Poverennaya EV. Proteoforms: Methods of Analysis and Clinical Prospects. Mol Biol 2018. [DOI: 10.1134/s0026893318030068] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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Dittrich J, Adam M, Maas H, Hecht M, Reinicke M, Ruhaak LR, Cobbaert C, Engel C, Wirkner K, Löffler M, Thiery J, Ceglarek U. Targeted On-line SPE-LC-MS/MS Assay for the Quantitation of 12 Apolipoproteins from Human Blood. Proteomics 2018; 18. [PMID: 29280342 DOI: 10.1002/pmic.201700279] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2017] [Revised: 12/01/2017] [Indexed: 12/22/2022]
Abstract
Laborious sample pretreatment of biological samples represents the most limiting factor for the translation of targeted proteomics assays from research to clinical routine. An optimized method for the simultaneous quantitation of 12 major apolipoproteins (apos) combining on-line SPE and fast LC-MS/MS analysis in 6.5 min total run time was developed, reducing the manual sample pretreatment time of 3 μL serum or plasma by 60%. Within-run and between-day imprecisions below 10 and 15% (n = 10) and high recovery rates (94-131%) were obtained applying the high-throughput setup. High-quality porcine trypsin was used, which outperformed cost-effective bovine trypsin regarding digestion efficiency. Comparisons with immunoassays and another LC-MS/MS assay demonstrated good correlation (Pearson's R: 0.81-0.98). Further, requirements on sample quality concerning sampling, processing, and long-term storage up to 1 year were investigated revealing significant influences of the applied sampling material and coagulant on quantitation results. Apo profiles of 1339 subjects of the LIFE-Adult-Study were associated with lifestyle and physiological parameters as well as establish parameters of lipid metabolism (e.g., triglycerides, cholesterol). Besides gender effects, most significant impact was seen regarding lipid-lowering medication. In conclusion, this novel highly standardized, high-throughput targeted proteomics assay utilizes a fast, simultaneous analysis of 12 apos from least sample amounts.
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Affiliation(s)
- Julia Dittrich
- Institute of Laboratory Medicine, Clinical Chemistry and Molecular Diagnostics, University Hospital Leipzig, Leipzig, Germany.,LIFE, Leipzig Research Center for Civilization Diseases, Leipzig University, Leipzig, Germany
| | - Melanie Adam
- Institute of Laboratory Medicine, Clinical Chemistry and Molecular Diagnostics, University Hospital Leipzig, Leipzig, Germany
| | - Hilke Maas
- Institute of Laboratory Medicine, Clinical Chemistry and Molecular Diagnostics, University Hospital Leipzig, Leipzig, Germany
| | - Max Hecht
- Institute of Laboratory Medicine, Clinical Chemistry and Molecular Diagnostics, University Hospital Leipzig, Leipzig, Germany
| | - Madlen Reinicke
- Institute of Laboratory Medicine, Clinical Chemistry and Molecular Diagnostics, University Hospital Leipzig, Leipzig, Germany
| | - L Renee Ruhaak
- Department of Clinical Chemistry and Laboratory Medicine, Leiden University Medical Center, Leiden, The Netherlands
| | - Christa Cobbaert
- Department of Clinical Chemistry and Laboratory Medicine, Leiden University Medical Center, Leiden, The Netherlands
| | - Christoph Engel
- LIFE, Leipzig Research Center for Civilization Diseases, Leipzig University, Leipzig, Germany.,Institute for Medical Informatics, Statistics and Epidemiology, Leipzig University, Leipzig, Germany
| | - Kerstin Wirkner
- LIFE, Leipzig Research Center for Civilization Diseases, Leipzig University, Leipzig, Germany
| | - Markus Löffler
- LIFE, Leipzig Research Center for Civilization Diseases, Leipzig University, Leipzig, Germany.,Institute for Medical Informatics, Statistics and Epidemiology, Leipzig University, Leipzig, Germany
| | - Joachim Thiery
- Institute of Laboratory Medicine, Clinical Chemistry and Molecular Diagnostics, University Hospital Leipzig, Leipzig, Germany.,LIFE, Leipzig Research Center for Civilization Diseases, Leipzig University, Leipzig, Germany
| | - Uta Ceglarek
- Institute of Laboratory Medicine, Clinical Chemistry and Molecular Diagnostics, University Hospital Leipzig, Leipzig, Germany.,LIFE, Leipzig Research Center for Civilization Diseases, Leipzig University, Leipzig, Germany
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Silva LM, Clements JA. Mass spectrometry based proteomics analyses in kallikrein-related peptidase research: implications for cancer research and therapy. Expert Rev Proteomics 2017; 14:1119-1130. [PMID: 29025353 DOI: 10.1080/14789450.2017.1389637] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
INTRODUCTION Kallikrein-related peptidases (KLKs) are a family of serine peptidases that are deregulated in numerous pathological conditions, with a multitude of KLK-mediated functional roles implicated in the progression of cancer. Advances in multidimensional mass spectrometry (MS)-based proteomics have facilitated the quantitative measurement of deregulated KLK expression in cancer, identifying certain KLKs, as well as their substrates, as potential cancer biomarkers. Areas covered: In this review, we discuss how these approaches have been utilized for KLK biomarker discovery and unbiased substrate determination in complex protein pools that mimic the in vivo extracellular microenvironment. Expert commentary: Although a limited number of studies have been performed, the quantity of information generated has greatly improved our understanding of the functional roles of KLKs in cancer progression. In addition, these data suggest additional means through which deregulated KLK expression may be targeted in cancer treatment, highlighting the potential therapeutic value of these state-of-the-art MS-based studies.
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Affiliation(s)
- Lakmali Munasinghage Silva
- a Proteases and Tissue Remodeling Section, Oral and Pharyngeal Cancer Branch , National Institute of Dental and Craniofacial Research, National Institutes of Health , Bethesda , MD , USA
| | - Judith Ann Clements
- b School of Biomedical Sciences , Institute of Health and Biomedical Innovation (IHBI), Queensland University of Technology (QUT), Translational Research Institute , Woolloongabba , Australia
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van den Broek I, Sobhani K, Van Eyk JE. Advances in quantifying apolipoproteins using LC-MS/MS technology: implications for the clinic. Expert Rev Proteomics 2017; 14:869-880. [PMID: 28870113 DOI: 10.1080/14789450.2017.1374859] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
INTRODUCTION Apolipoproteins play a key role in pre-, pro-, and anti-atherosclerotic processes and have become important circulating biomarkers for the prediction of cardiovascular disease (CVD) risk. Whereas currently clinical immunoassays are not available for most apolipoproteins and lack the capacity for multiplexing, liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS) allows simultaneous, highly-specific, and precise quantification of multiple apolipoproteins. Areas covered: We discuss LC-MS/MS methods for quantification of apolipoproteins reported in the literature and highlight key requirements for clinical use. Besides the advances in sample preparation and LC-MS/MS technologies, this overview also discusses advances in proteoform analysis and applications of dried blood/plasma collection. Expert commentary: Standardized quantification using LC-MS/MS technology has been demonstrated for apolipoprotein A-I and B. However, for implementation in clinical CVD risk assessment, LC-MS/MS must bring significant added clinical value in comparison to fast, standardized, and straightforward clinical (immuno)assays. Ongoing advances in accuracy and multiplexing capacity of LC-MS/MS, nonetheless, bear potential to enable standardized and interpretable personalized profiling of a patient's CVD risk by simultaneous quantification of multiple apolipoproteins and -variants. We, moreover, anticipate further personalization of CVD risk assessment by the potential of LC-MS/MS to enable simultaneous genotyping and remote monitoring using dried blood/plasma collection devices.
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Affiliation(s)
- Irene van den Broek
- a Cedars-Sinai Medical Center, The Advanced Clinical Biosystems Research Institute , The Heart Institute , Los Angeles , CA , USA
| | - Kimia Sobhani
- b Department of Pathology and Laboratory Medicine , Cedars-Sinai Medical Center , Los Angeles , CA , USA
| | - Jennifer E Van Eyk
- a Cedars-Sinai Medical Center, The Advanced Clinical Biosystems Research Institute , The Heart Institute , Los Angeles , CA , USA
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van den Broek I, Romijn FPHTM, Nouta J, van der Laarse A, Drijfhout JW, Smit NPM, van der Burgt YEM, Cobbaert CM. Automated Multiplex LC-MS/MS Assay for Quantifying Serum Apolipoproteins A-I, B, C-I, C-II, C-III, and E with Qualitative Apolipoprotein E Phenotyping. Clin Chem 2016; 62:188-97. [DOI: 10.1373/clinchem.2015.246702] [Citation(s) in RCA: 69] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2015] [Accepted: 11/03/2015] [Indexed: 12/31/2022]
Abstract
Abstract
BACKGROUND
Direct and calculated measures of lipoprotein fractions for cardiovascular risk assessment suffer from analytical inaccuracy in certain dyslipidemic and pathological states, most commonly hypertriglyceridemia. LC-MS/MS has proven suitable for multiplexed quantification and phenotyping of apolipoproteins. We developed and provisionally validated an automated assay for quantification of apolipoprotein (apo) A-I, B, C-I, C-II, C-III, and E and simultaneous qualitative assessment of apoE phenotypes.
METHODS
We used 5 value-assigned human serum pools for external calibration. Serum proteins were denatured, reduced, and alkylated according to standard mass spectrometry–based proteomics procedures. After trypsin digestion, peptides were analyzed by LC-MS/MS. For each peptide, we measured 2 transitions. We compared LC-MS/MS results to those obtained by an immunoturbidimetric assay or ELISA.
RESULTS
Intraassay CVs were 2.3%–5.5%, and total CVs were 2.5%–5.9%. The LC-MS/MS assay correlated (R = 0.975–0.995) with immunoturbidimetric assays with Conformité Européenne marking for apoA-I, apoB, apoC-II, apoC-III, and apoE in normotriglyceridemic (n = 54) and hypertriglyceridemic (n = 46) sera. Results were interchangeable for apoA-I ≤3.0 g/L (Deming slope 1.014) and for apoB-100 ≤1.8 g/L (Deming slope 1.016) and were traceable to higher-order standards.
CONCLUSIONS
The multiplex format provides an opportunity for new diagnostic and pathophysiologic insights into types of dyslipidemia and allows a more personalized approach for diagnosis and treatment of lipid abnormalities.
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Affiliation(s)
| | | | - Jan Nouta
- Department of Clinical Chemistry and Laboratory Medicine
| | | | | | - Nico P M Smit
- Department of Clinical Chemistry and Laboratory Medicine
| | - Yuri E M van der Burgt
- Department of Clinical Chemistry and Laboratory Medicine
- Center for Proteomics and Metabolomics, Leiden University Medical Center, Leiden, the Netherlands
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Kiseleva OI, Romashova YA, Moskaleva NE, Petushkova NA, Teryaeva NB, Belyaev AY, Lisitsa AV. Plasma preparation to measure FDA-approved protein markers by selected reaction monitoring. Clin Transl Med 2015; 4:32. [PMID: 26471814 PMCID: PMC4607682 DOI: 10.1186/s40169-015-0071-4] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2015] [Accepted: 09/02/2015] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The development of commercially available panels for human blood plasma screening via selected reaction monitoring (SRM) offers reliable, cost-efficient and highly-standardized discovery and validation of protein biomarkers. However, protein detection by SRM can be hampered by interfering peptide fragment ions. To estimate the influence of interference on protein detection, we performed different types of sample preparation and implemented SRM measurements for well-characterized protein targets approved by the US Food and Drug Administration. METHODS We used the PlasmaDeepDive™ SRM assay from BiognoSYS AG for absolute quantification of 18 proteins in 19 samples of human plasma using three different protocols for sample preparation. SRM measurements were performed using iRT standards for retention time normalization and isotopically-labeled reference peptides for absolute quantification. SpectroDive™ software was used for automated detection of reliable peak groups. RESULTS Fourteen targeted proteins were quantitatively measured in more than half of the samples. Depletion of highly-abundant plasma proteins and peptide fraction clean-up on centrifuge plates resulted in detection of all 18 targeted proteins in femtomolar to picomolar concentrations. CONCLUSIONS It was shown that commercially designed SRM kits are suitable for SRM detection of well-established plasma/serum biomarkers.
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Affiliation(s)
- Olga I Kiseleva
- Orekhovich Institute of Biomedical Chemistry, Pogodinskaya str. 10/8, 119121, Moscow, Russia.
| | - Yulia A Romashova
- Orekhovich Institute of Biomedical Chemistry, Pogodinskaya str. 10/8, 119121, Moscow, Russia.
| | - Natalia E Moskaleva
- Orekhovich Institute of Biomedical Chemistry, Pogodinskaya str. 10/8, 119121, Moscow, Russia.
| | - Natalia A Petushkova
- Orekhovich Institute of Biomedical Chemistry, Pogodinskaya str. 10/8, 119121, Moscow, Russia.
| | - Nadezhda B Teryaeva
- Burdenko Neurosurgery Institute, 4th Tverskaya-Yamskaya str. 16, 125047, Moscow, Russia.
| | - Artem Yu Belyaev
- Burdenko Neurosurgery Institute, 4th Tverskaya-Yamskaya str. 16, 125047, Moscow, Russia.
| | - Andrey V Lisitsa
- Orekhovich Institute of Biomedical Chemistry, Pogodinskaya str. 10/8, 119121, Moscow, Russia.
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Smit NPM, Romijn FPHTM, van den Broek I, Drijfhout JW, Haex M, van der Laarse A, van der Burgt YEM, Cobbaert CM. Metrological traceability in mass spectrometry-based targeted protein quantitation: a proof-of-principle study for serum apolipoproteins A-I and B100. J Proteomics 2014; 109:143-61. [PMID: 24972322 DOI: 10.1016/j.jprot.2014.06.015] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2014] [Revised: 05/22/2014] [Accepted: 06/16/2014] [Indexed: 12/23/2022]
Abstract
UNLABELLED In this study, we have followed up on previous liquid chromatography (LC) multiple reaction monitoring (MRM) mass spectrometry (MS) approaches for measurement of apolipoprotein (apo) A-I and apo B100 in serum aiming for implementation of a multiplexed assay in a clinical chemistry laboratory with full metrological traceability. Signature peptides were selected and detected by dynamic MRM, and stable isotope labeled (SIL)-peptides were used as internal standards. Five apo A-I and four apo B100 peptides were measured in serum digests with linearity (R(2)>0.992) in the physiologically relevant concentration ranges. Linearity with regard to protein concentration was ascertained at five concentration levels (R(2)>0.926 and R(2)>0.965, for the apo A-I and apo B100 peptides, respectively). Three native value-assigned sera were used as external calibrators for further method verification. Imprecision values on sample preparation and LC-MS/MS acquisition were below the established minimal specifications for apo A-I and apo B100 (5.0% and 5.3%, respectively). Correlation of LC-MS/MS results with immunoturbidimetric assay results, for normo- and hypertriglyceridemic samples, showed R(2)>0.944 for apo A-I and R(2)>0.964 for apo B100. This LC-MS/MS method has potential for clinical application in normo- and dyslipidemic patients. BIOLOGICAL SIGNIFICANCE Measurement of apo A-I and apo B100 may offer an alternative to high and low density lipoprotein cholesterol (HDL-c and LDL-c) methods for cardiovascular disease risk assessment in dyslipidemic patients [1]. An LC-MS/MS method for apo A-I and apo B100 has the advantage of antibody independent and specific detection of protein signature peptides. The introduction of an LC-MS/MS method for apo A-I and apo B100 can serve as an example for many existing and newly developed (multiplex) biomarker methods in quantitative clinical chemistry proteomics (qCCP). Such LC-MS/MS methods should meet basic clinical chemistry principles with regard to test evaluation [2]. Criteria for imprecision should be pre-defined, e.g., based on biological variation. The use of commutable and traceable serum-based calibrators will improve inter-laboratory reproducibility of LC-MS/MS methods and may contribute to a more rapid transition of biomarker discovery to clinical utility with benefit for the patient treatment and improvement of general health care.
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Affiliation(s)
- Nico P M Smit
- Department of Clinical Chemistry and Laboratory Medicine, Leiden University Medical Center, Albinusdreef 2, 2333 ZA, Leiden, The Netherlands.
| | - Fred P H T M Romijn
- Department of Clinical Chemistry and Laboratory Medicine, Leiden University Medical Center, Albinusdreef 2, 2333 ZA, Leiden, The Netherlands
| | - Irene van den Broek
- Department of Clinical Chemistry and Laboratory Medicine, Leiden University Medical Center, Albinusdreef 2, 2333 ZA, Leiden, The Netherlands
| | - Jan W Drijfhout
- Department of Immunohematology and Bloodtransfusion, Leiden University Medical Center, Albinusdreef 2, 2333 ZA, Leiden, The Netherlands
| | - Martin Haex
- Agilent Technologies Netherlands B.V., Amstelveen, The Netherlands
| | - Arnoud van der Laarse
- Department of Clinical Chemistry and Laboratory Medicine, Leiden University Medical Center, Albinusdreef 2, 2333 ZA, Leiden, The Netherlands
| | - Yuri E M van der Burgt
- Center for Proteomics and Metabolomics, Leiden University Medical Center, Albinusdreef 2, 2333 ZA, Leiden, The Netherlands
| | - Christa M Cobbaert
- Department of Clinical Chemistry and Laboratory Medicine, Leiden University Medical Center, Albinusdreef 2, 2333 ZA, Leiden, The Netherlands.
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Ansari D, Aronsson L, Sasor A, Welinder C, Rezeli M, Marko-Varga G, Andersson R. The role of quantitative mass spectrometry in the discovery of pancreatic cancer biomarkers for translational science. J Transl Med 2014; 12:87. [PMID: 24708694 PMCID: PMC3998064 DOI: 10.1186/1479-5876-12-87] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2014] [Accepted: 03/13/2014] [Indexed: 02/06/2023] Open
Abstract
In the post-genomic era, it has become evident that genetic changes alone are not sufficient to understand most disease processes including pancreatic cancer. Genome sequencing has revealed a complex set of genetic alterations in pancreatic cancer such as point mutations, chromosomal losses, gene amplifications and telomere shortening that drive cancerous growth through specific signaling pathways. Proteome-based approaches are important complements to genomic data and provide crucial information of the target driver molecules and their post-translational modifications. By applying quantitative mass spectrometry, this is an alternative way to identify biomarkers for early diagnosis and personalized medicine. We review the current quantitative mass spectrometric technologies and analyses that have been developed and applied in the last decade in the context of pancreatic cancer. Examples of candidate biomarkers that have been identified from these pancreas studies include among others, asporin, CD9, CXC chemokine ligand 7, fibronectin 1, galectin-1, gelsolin, intercellular adhesion molecule 1, insulin-like growth factor binding protein 2, metalloproteinase inhibitor 1, stromal cell derived factor 4, and transforming growth factor beta-induced protein. Many of these proteins are involved in various steps in pancreatic tumor progression including cell proliferation, adhesion, migration, invasion, metastasis, immune response and angiogenesis. These new protein candidates may provide essential information for the development of protein diagnostics and targeted therapies. We further argue that new strategies must be advanced and established for the integration of proteomic, transcriptomic and genomic data, in order to enhance biomarker translation. Large scale studies with meta data processing will pave the way for novel and unexpected correlations within pancreatic cancer, that will benefit the patient, with targeted treatment.
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Affiliation(s)
| | | | | | | | | | | | - Roland Andersson
- Department of Surgery, Clinical Sciences Lund, Lund University, and Skåne University Hospital, SE-221 85 Lund, Sweden.
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Garbis SD, Townsend PA. Proteomics of human prostate cancer biospecimens: the global, systems-wide perspective for Protein markers with potential clinical utility. Expert Rev Proteomics 2014; 10:337-54. [DOI: 10.1586/14789450.2013.827408] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
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van den Broek I, Smit NPM, Romijn FPHTM, van der Laarse A, Deelder AM, van der Burgt YEM, Cobbaert CM. Evaluation of interspecimen trypsin digestion efficiency prior to multiple reaction monitoring-based absolute protein quantification with native protein calibrators. J Proteome Res 2013; 12:5760-74. [PMID: 24168082 DOI: 10.1021/pr400763d] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Implementation of quantitative clinical chemistry proteomics (qCCP) requires targeted proteomics approaches, usually involving bottom-up multiple reaction monitoring-mass spectrometry (MRM-MS) with stable-isotope labeled standard (SIS) peptides, to move toward more accurate measurements. Two aspects of qCCP that deserve special attention are (1) proper calibration and (2) the assurance of consistent digestion. Here, we describe the evaluation of tryptic digestion efficiency by monitoring various signature peptides, missed cleavages, and modifications during proteolysis of apolipoprotein A-I and B in normo- and hypertriglyceridemic specimens. Absolute quantification of apolipoprotein A-I and B was performed by LC-MRM-MS with SIS peptide internal standards at two time points (4 and 20 h), using three native protein calibrators. Comparison with an immunoturbidimetric assay revealed recoveries of 99.4 ± 6.5% for apolipoprotein A-I and 102.6 ± 7.2% for apolipoprotein B after 4 h of trypsin digestion. Protein recoveries after 20 h trypsin incubation equaled 95.9 ± 6.9% and 106.0 ± 10.0% for apolipoproteins A-I and B, respectively. In conclusion, the use of metrologically traceable, native protein calibrators looks promising for accurate quantification of apolipoprotein A-I and B. Selection of rapidly formed peptides, that is, with no or minor missed cleavages, and the use of short trypsin incubation times for these efficiently cleaved peptides are likely to further reduce the variability introduced by trypsin digestion and to improve the traceability of test results to reach the desirable analytical performance for clinical chemistry application.
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Affiliation(s)
- Irene van den Broek
- Department of Clinical Chemistry and Laboratory Medicine, Leiden University Medical Center (LUMC) , Albinusdreef 2, 2333 ZA, Leiden, the Netherlands
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Yang WH, Gu HB, Chen B, Li J, Fan QW, Yuan YF, Wang X. Evaluation of SLOG/TCI-III pediatric system on target control infusion of propofol. Lab Invest 2011; 9:187. [PMID: 22044738 PMCID: PMC3221635 DOI: 10.1186/1479-5876-9-187] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2011] [Accepted: 11/01/2011] [Indexed: 11/24/2022]
Abstract
Background The target-controlled infusion-III (SLOG/TCI-III) system was derived from a model set up by the local pediatric population for target control infusion of propofol. Methods The current study aimed at evaluating the difference between target concentrations of propofol and performance, which was measured using the SLOG/TCI-III system in children. Thirty children fulfilling the I-II criteria according to American Society of Anesthesiology were enrolled in the study. The target plasma concentration of propofol was fed into the SLOG/TCI-III system and compared with the measured concentrations of propofol. Blood samples were collected and analyzed by high performance liquid chromatography with fluorescence detector. The performance error (PE) was determined for each measured blood propofol concentration. The performances of the TCI-III system were determined by the median performance error (MDPE), the median absolute performance error (MDAPE), and Wobble (the median absolute deviation of each PE from the MDPE), respectively. Results Concentration against target concentration showed good linear correlation: concentration = 1.3428 target concentration - 0.2633 (r = 0.8667). The MDPE and MDAPE of the pediatric system were 10 and 22%, respectively, and the median value for Wobble was 24%. MDPE and MDAPE were less than 15 and 30%, respectively. Conclusions The performance of TCI-III system seems to be in the accepted limits for clinical practice in children.
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