1
|
An QQ, Feng XZ, Zhan T, Cheng YY, Han GC, Chen Z, Kraatz HB. A simple synthesis of a core-shell structure PPy-Au nanocomposite for immunosensing of C-reactive protein. Talanta 2024; 267:125158. [PMID: 37683320 DOI: 10.1016/j.talanta.2023.125158] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2023] [Revised: 07/21/2023] [Accepted: 09/02/2023] [Indexed: 09/10/2023]
Abstract
High-sensitivity C-reactive protein (hs-CRP) is an inflammatory biomarker and can accurately predict the development of cardiovascular disease (CVD). We synthesized a core-shell structure PPy-Au nanocomposite in situ by chemically oxidizing pyrrole (Py) with HAuCl4 and the produced Au nanoparticles realized the doping in the polymerization. Analysis of morphology and energy spectrum as well as electrochemical characterization confirmed the successful one-pot synthesis. The conductive polymers with porous structure provide abundant sites for anti-CRP binding and effectively enhanced the sensitivity of the label-free BSA/anti-CRP/PPy-Au/GCE immunosensor. Its analytical performance was observed using differential pulse voltammetry (DPV), with a linear range from 0.0005 to 60 μg mL-1 and a detection limit of 0.17 ng mL-1. The platform demonstrated satisfactory selectivity, stability, and reproducibility. To validate its clinical application, we detected CRP in human serum samples with a recovery rate of 101.00-105.95% and investigated the consistency of the developed method and immunoturbidimetry with a deviation between -1.2% and +3.2%, suggesting great potential for use in point-of-care testing (POCT).
Collapse
Affiliation(s)
- Qi-Qi An
- School of Life and Environmental Sciences, Guilin University of Electronic Technology, Guilin, 541004, PR China
| | - Xiao-Zhen Feng
- School of Life and Environmental Sciences, Guilin University of Electronic Technology, Guilin, 541004, PR China
| | - Tao Zhan
- School of Life and Environmental Sciences, Guilin University of Electronic Technology, Guilin, 541004, PR China
| | - Yun-Yun Cheng
- School of Life and Environmental Sciences, Guilin University of Electronic Technology, Guilin, 541004, PR China
| | - Guo-Cheng Han
- School of Life and Environmental Sciences, Guilin University of Electronic Technology, Guilin, 541004, PR China.
| | - Zhencheng Chen
- School of Life and Environmental Sciences, Guilin University of Electronic Technology, Guilin, 541004, PR China.
| | - Heinz-Bernhard Kraatz
- Department of Physical and Environmental Sciences, University of Toronto Scarborough, Toronto, Ontario, M1C 1A4, Canada.
| |
Collapse
|
2
|
Mesaros C, Blair IA. Mass spectrometry-based approaches to targeted quantitative proteomics in cardiovascular disease. Clin Proteomics 2016; 13:20. [PMID: 27713681 PMCID: PMC5050566 DOI: 10.1186/s12014-016-9121-1] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2016] [Accepted: 07/19/2016] [Indexed: 01/11/2023] Open
Abstract
Mass spectrometry-based proteomics methodology has become an important tool in elucidating some of the underlying mechanisms involved in cardiovascular disease. The present review provides details on selected important protein targets where highly selective and specific mass spectrometry-based approaches have led to important new findings and provided new mechanistic information. The role of six proteins involved in the etiology of cardiovascular disease (acetylated platelet cyclooxygenase-1, serum apolipoprotein A1, apolipoprotein C-III, serum C-reactive protein, serum high mobility group box-1 protein, insulin-like growth factor I) and their quantification has been discussed. There are an increasing number of examples where highly selective mass spectrometry-based quantification has provided new important data that could not be obtained with less labor intensive and cheaper immunoassay-based procedures. It is anticipated that these findings will lead to significant advances in a number of important issues related to the role of specific proteins in cardiovascular disease. The availability of a new generation of high-resolution high-sensitivity mass spectrometers will greatly facilitate these studies so that in the future it will be possible to analyze serum proteins of relevance to cardiovascular disease with levels of specificity and/or sensitivity that cannot be attained by immunoassay-based procedures.
Collapse
Affiliation(s)
- Clementina Mesaros
- Penn SRP Center and Center of Excellence in Environmental Toxicology, Department of Systems Pharmacology and Translational Therapeutics, University of Pennsylvania, Philadelphia, PA 19104 USA ; BluePen Biomarkers, 3401 Grays Ferry Avenue, Philadelphia, PA 19146-2799 USA
| | - Ian A Blair
- Penn SRP Center and Center of Excellence in Environmental Toxicology, Department of Systems Pharmacology and Translational Therapeutics, University of Pennsylvania, Philadelphia, PA 19104 USA ; BluePen Biomarkers, 3401 Grays Ferry Avenue, Philadelphia, PA 19146-2799 USA
| |
Collapse
|
3
|
Bioanalytical advances in assays for C-reactive protein. Biotechnol Adv 2016; 34:272-90. [DOI: 10.1016/j.biotechadv.2015.12.010] [Citation(s) in RCA: 94] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2015] [Revised: 12/17/2015] [Accepted: 12/18/2015] [Indexed: 01/08/2023]
|
4
|
Vashist SK, Czilwik G, van Oordt T, von Stetten F, Zengerle R, Marion Schneider E, Luong JH. One-step kinetics-based immunoassay for the highly sensitive detection of C-reactive protein in less than 30min. Anal Biochem 2014; 456:32-7. [DOI: 10.1016/j.ab.2014.04.004] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2014] [Revised: 04/01/2014] [Accepted: 04/03/2014] [Indexed: 11/25/2022]
|
5
|
Bronsema KJ, Bischoff R, van de Merbel NC. High-Sensitivity LC-MS/MS Quantification of Peptides and Proteins in Complex Biological Samples: The Impact of Enzymatic Digestion and Internal Standard Selection on Method Performance. Anal Chem 2013; 85:9528-35. [DOI: 10.1021/ac4015116] [Citation(s) in RCA: 68] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Kees J. Bronsema
- Analytical Biochemistry, Department
of Pharmacy, University of Groningen, A. Deusinglaan 1, 9713 AV Groningen, The Netherlands
- Bioanalytical
Laboratory, PRA, Early Development Services, Westerbrink 3, 9405 BJ, Assen, The Netherlands
| | - Rainer Bischoff
- Analytical Biochemistry, Department
of Pharmacy, University of Groningen, A. Deusinglaan 1, 9713 AV Groningen, The Netherlands
| | - Nico C. van de Merbel
- Analytical Biochemistry, Department
of Pharmacy, University of Groningen, A. Deusinglaan 1, 9713 AV Groningen, The Netherlands
- Bioanalytical
Laboratory, PRA, Early Development Services, Westerbrink 3, 9405 BJ, Assen, The Netherlands
| |
Collapse
|
6
|
Abstract
LC–MS has become the method-of-choice in small-molecule drug bioanalysis (molecular mass <800 Da) and is also increasingly being applied as an alternative to ligand-binding assays for the bioanalytical determination of biopharmaceuticals. Triple quadrupole MS is the established bioanalytical technique due to its unpreceded selectivity and sensitivity, but high-resolution accurate-mass MS is recently gaining ground due to its ability to provide simultaneous quantitative and qualitative analysis of drugs and their metabolites. This article discusses current trends in the field of bioanalytical LC–MS (until September 2012), and provides an overview of currently available commercial triple quadrupole MS and high-resolution LC–MS instruments as applied for the bioanalysis of small-molecule and biopharmaceutical drugs.
Collapse
|
7
|
Gianazza E, Wait R, Eberini I, Sensi C, Sironi L, Miller I. Proteomics of rat biological fluids — The tenth anniversary update. J Proteomics 2012; 75:3113-28. [DOI: 10.1016/j.jprot.2012.03.053] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2012] [Revised: 03/26/2012] [Accepted: 03/28/2012] [Indexed: 01/29/2023]
|
8
|
Shi T, Su D, Liu T, Tang K, Camp DG, Qian WJ, Smith RD. Advancing the sensitivity of selected reaction monitoring-based targeted quantitative proteomics. Proteomics 2012; 12:1074-92. [PMID: 22577010 PMCID: PMC3375056 DOI: 10.1002/pmic.201100436] [Citation(s) in RCA: 157] [Impact Index Per Article: 13.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2011] [Accepted: 01/12/2012] [Indexed: 12/13/2022]
Abstract
Selected reaction monitoring (SRM) - also known as multiple reaction monitoring (MRM) - has emerged as a promising high-throughput targeted protein quantification technology for candidate biomarker verification and systems biology applications. A major bottleneck for current SRM technology, however, is insufficient sensitivity for, e.g. detecting low-abundance biomarkers likely present at the low ng/mL to pg/mL range in human blood plasma or serum, or extremely low-abundance signaling proteins in cells or tissues. Herein, we review recent advances in methods and technologies, including front-end immunoaffinity depletion, fractionation, selective enrichment of target proteins/peptides including posttranslational modifications, as well as advances in MS instrumentation which have significantly enhanced the overall sensitivity of SRM assays and enabled the detection of low-abundance proteins at low- to sub-ng/mL level in human blood plasma or serum. General perspectives on the potential of achieving sufficient sensitivity for detection of pg/mL level proteins in plasma are also discussed.
Collapse
Affiliation(s)
- Tujin Shi
- Biological Sciences Division and Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory, Richland, WA 99352
| | - Dian Su
- Biological Sciences Division and Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory, Richland, WA 99352
| | - Tao Liu
- Biological Sciences Division and Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory, Richland, WA 99352
| | - Keqi Tang
- Biological Sciences Division and Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory, Richland, WA 99352
| | - David G. Camp
- Biological Sciences Division and Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory, Richland, WA 99352
| | - Wei-Jun Qian
- Biological Sciences Division and Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory, Richland, WA 99352
| | - Richard D. Smith
- Biological Sciences Division and Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory, Richland, WA 99352
| |
Collapse
|
9
|
Internal standards in the quantitative determination of protein biopharmaceuticals using liquid chromatography coupled to mass spectrometry. J Chromatogr B Analyt Technol Biomed Life Sci 2012; 893-894:1-14. [DOI: 10.1016/j.jchromb.2012.02.021] [Citation(s) in RCA: 104] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2011] [Revised: 02/10/2012] [Accepted: 02/13/2012] [Indexed: 02/05/2023]
|
10
|
Li J, Kelm KB, Tezak Z. Regulatory perspective on translating proteomic biomarkers to clinical diagnostics. J Proteomics 2011; 74:2682-90. [PMID: 21856459 DOI: 10.1016/j.jprot.2011.07.028] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2010] [Revised: 07/13/2011] [Accepted: 07/27/2011] [Indexed: 01/31/2023]
Abstract
Issues associated with the translation of complex proteomic biomarkers from discovery to clinical diagnostics have been widely discussed among academic researchers, government agencies, as well as assay and instrumentation manufacturers. Here, we provide an overview of the regulatory framework and type of information that is typically required in order to evaluate in vitro diagnostic tests regulated by the Office of In Vitro Diagnostic Device Evaluation and Safety (OIVD) at the US Food and Drug Administration (FDA), with the focus on some of the issues specific to protein-based complex tests. Technological points pertaining to mass spectrometry platforms and assessment of potential concerns important for assurance of safety and effectiveness of this type of assays when introduced into clinical diagnostic use, as well as general approaches for evaluating the performance of these devices, are discussed.
Collapse
Affiliation(s)
- Jinong Li
- Office of In Vitro Diagnostic Device Evaluation and Safety, Center for Devices and Radiological Health, U.S. Food and Drug Administration, Silver Spring, MD, United States.
| | | | | |
Collapse
|
11
|
Xu K, Liu L, Saad OM, Baudys J, Williams L, Leipold D, Shen B, Raab H, Junutula JR, Kim A, Kaur S. Characterization of intact antibody–drug conjugates from plasma/serum in vivo by affinity capture capillary liquid chromatography–mass spectrometry. Anal Biochem 2011; 412:56-66. [DOI: 10.1016/j.ab.2011.01.004] [Citation(s) in RCA: 113] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2010] [Revised: 12/24/2010] [Accepted: 01/04/2011] [Indexed: 10/18/2022]
|
12
|
Horvatovich PL, Bischoff R. Current technological challenges in biomarker discovery and validation. EUROPEAN JOURNAL OF MASS SPECTROMETRY (CHICHESTER, ENGLAND) 2010; 16:101-121. [PMID: 20065518 DOI: 10.1255/ejms.1050] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
In this review we will give an overview of the issues related to biomarker discovery studies with a focus on liquid chromatography-mass spectrometry (LC-MS) methods. Biomarker discovery is based on a close collaboration between clinicians, analytical scientists and chemometritians/statisticians. It is critical to define the final purpose of a biomarker or biomarker pattern at the onset of the study and to select case and control samples accordingly. This is followed by designing the experiment, starting with the sampling strategy, sample collection, storage and separation protocols, choice and validation of the quantitative profiling platform followed by data processing, statistical analysis and validation workflows. Biomarker candidates that result after statistical validation should be submitted for further validation and, ideally, be connected to the disease mechanism after their identification. Since most discovery studies work with a relatively small number of samples, it is necessary to assess the specificity and sensitivity of a given biomarker-based assay in a larger set of independent samples, preferably analyzed at another clinical center. Targeted analytical methods of higher throughput than the original discovery method are needed at this point and LC-tandem mass spectrometry is gaining acceptance in this field. Throughout this review, we will focus on possible sources of variance and how they can be assessed and reduced in order to avoid false positives and to reduce the number of false negatives in biomarker discovery research.
Collapse
Affiliation(s)
- Peter L Horvatovich
- Analytical Biochemistry, Department of Pharmacy, University of Groningen, A. Deusinglaan 1, 9713 AV Groningen, The Netherlands.
| | | |
Collapse
|
13
|
Kilpatrick EL, Bunk DM. Reference Measurement Procedure Development for C-Reactive Protein in Human Serum. Anal Chem 2009; 81:8610-6. [DOI: 10.1021/ac901597h] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Affiliation(s)
- Eric L. Kilpatrick
- National Institute of Standards and Technology, Chemical Sciences Technology Laboratory, Analytical Chemistry Division, 331 Fort Johnson Road, Charleston, South Carolina 29412, and National Institute of Standards and Technology, Chemical Sciences Technology Laboratory, Analytical Chemistry Division, 100 Bureau Drive, Gaithersburg, Maryland 20899
| | - David M. Bunk
- National Institute of Standards and Technology, Chemical Sciences Technology Laboratory, Analytical Chemistry Division, 331 Fort Johnson Road, Charleston, South Carolina 29412, and National Institute of Standards and Technology, Chemical Sciences Technology Laboratory, Analytical Chemistry Division, 100 Bureau Drive, Gaithersburg, Maryland 20899
| |
Collapse
|
14
|
Addona TA, Abbatiello SE, Schilling B, Skates SJ, Mani DR, Bunk DM, Spiegelman CH, Zimmerman LJ, Ham AJL, Keshishian H, Hall SC, Allen S, Blackman RK, Borchers CH, Buck C, Cardasis HL, Cusack MP, Dodder NG, Gibson BW, Held JM, Hiltke T, Jackson A, Johansen EB, Kinsinger CR, Li J, Mesri M, Neubert TA, Niles RK, Pulsipher TC, Ransohoff D, Rodriguez H, Rudnick PA, Smith D, Tabb DL, Tegeler TJ, Variyath AM, Vega-Montoto LJ, Wahlander A, Waldemarson S, Wang M, Whiteaker JR, Zhao L, Anderson NL, Fisher SJ, Liebler DC, Paulovich AG, Regnier FE, Tempst P, Carr SA. Multi-site assessment of the precision and reproducibility of multiple reaction monitoring-based measurements of proteins in plasma. Nat Biotechnol 2009; 27:633-41. [PMID: 19561596 DOI: 10.1038/nbt.1546] [Citation(s) in RCA: 828] [Impact Index Per Article: 55.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2009] [Accepted: 05/31/2009] [Indexed: 01/13/2023]
Abstract
Verification of candidate biomarkers relies upon specific, quantitative assays optimized for selective detection of target proteins, and is increasingly viewed as a critical step in the discovery pipeline that bridges unbiased biomarker discovery to preclinical validation. Although individual laboratories have demonstrated that multiple reaction monitoring (MRM) coupled with isotope dilution mass spectrometry can quantify candidate protein biomarkers in plasma, reproducibility and transferability of these assays between laboratories have not been demonstrated. We describe a multilaboratory study to assess reproducibility, recovery, linear dynamic range and limits of detection and quantification of multiplexed, MRM-based assays, conducted by NCI-CPTAC. Using common materials and standardized protocols, we demonstrate that these assays can be highly reproducible within and across laboratories and instrument platforms, and are sensitive to low mug/ml protein concentrations in unfractionated plasma. We provide data and benchmarks against which individual laboratories can compare their performance and evaluate new technologies for biomarker verification in plasma.
Collapse
Affiliation(s)
- Terri A Addona
- Broad Institute of MIT and Harvard, Cambridge, Massachusetts, USA
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
15
|
Paulovich AG, Whiteaker JR, Hoofnagle AN, Wang P. The interface between biomarker discovery and clinical validation: The tar pit of the protein biomarker pipeline. Proteomics Clin Appl 2008; 2:1386-1402. [PMID: 20976028 DOI: 10.1002/prca.200780174] [Citation(s) in RCA: 165] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
The application of "omics" technologies to biological samples generates hundreds to thousands of biomarker candidates; however, a discouragingly small number make it through the pipeline to clinical use. This is in large part due to the incredible mismatch between the large numbers of biomarker candidates and the paucity of reliable assays and methods for validation studies. We desperately need a pipeline that relieves this bottleneck between biomarker discovery and validation. This paper reviews the requirements for technologies to adequately credential biomarker candidates for costly clinical validation and proposes methods and systems to verify biomarker candidates. Models involving pooling of clinical samples, where appropriate, are discussed. We conclude that current proteomic technologies are on the cusp of significantly affecting translation of molecular diagnostics into the clinic.
Collapse
|
16
|
Whiteaker JR, Zhang H, Zhao L, Wang P, Kelly-Spratt KS, Ivey RG, Piening BD, Feng LC, Kasarda E, Gurley KE, Eng JK, Chodosh LA, Kemp CJ, McIntosh MW, Paulovich AG. Integrated pipeline for mass spectrometry-based discovery and confirmation of biomarkers demonstrated in a mouse model of breast cancer. J Proteome Res 2007; 6:3962-75. [PMID: 17711321 DOI: 10.1021/pr070202v] [Citation(s) in RCA: 157] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Despite their potential to impact diagnosis and treatment of cancer, few protein biomarkers are in clinical use. Biomarker discovery is plagued with difficulties ranging from technological (inability to globally interrogate proteomes) to biological (genetic and environmental differences among patients and their tumors). We urgently need paradigms for biomarker discovery. To minimize biological variation and facilitate testing of proteomic approaches, we employed a mouse model of breast cancer. Specifically, we performed LC-MS/MS of tumor and normal mammary tissue from a conditional HER2/Neu-driven mouse model of breast cancer, identifying 6758 peptides representing >700 proteins. We developed a novel statistical approach (SASPECT) for prioritizing proteins differentially represented in LC-MS/MS datasets and identified proteins over- or under-represented in tumors. Using a combination of antibody-based approaches and multiple reaction monitoring-mass spectrometry (MRM-MS), we confirmed the overproduction of multiple proteins at the tissue level, identified fibulin-2 as a plasma biomarker, and extensively characterized osteopontin as a plasma biomarker capable of early disease detection in the mouse. Our results show that a staged pipeline employing shotgun-based comparative proteomics for biomarker discovery and multiple reaction monitoring for confirmation of biomarker candidates is capable of finding novel tissue and plasma biomarkers in a mouse model of breast cancer. Furthermore, the approach can be extended to find biomarkers relevant to human disease.
Collapse
|
17
|
van den Broek I, Sparidans RW, Schellens JHM, Beijnen JH. Enzymatic digestion as a tool for the LC–MS/MS quantification of large peptides in biological matrices: Measurement of chymotryptic fragments from the HIV-1 fusion inhibitor enfuvirtide and its metabolite M-20 in human plasma. J Chromatogr B Analyt Technol Biomed Life Sci 2007; 854:245-59. [PMID: 17500050 DOI: 10.1016/j.jchromb.2007.04.026] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2007] [Revised: 04/17/2007] [Accepted: 04/22/2007] [Indexed: 11/23/2022]
Abstract
The use of enzymatic digests of the peptide HIV-1 fusion inhibitor enfuvirtide as a tool for the absolute quantification of this polypeptide (MW 4492 Da) in human plasma by LC-MS/MS has been evaluated. Two different methods applying digestion of enfuvirtide with chymotrypsin after solid phase extraction (SPE) of the plasma samples have therefore been developed and validated. One method used a stable isotopically labeled analog of the complete peptide (d60-enfuvirtide) as internal standard (IS) and could use as much as four different chymotryptic fragments for the quantification of enfuvirtide in a range of 100-10,000 ng/ml. Intra- and inter-assay precisions and deviations from the nominal concentrations varied for the different fragments, but were below 9% when the four results were averaged. The other method used a stable isotopically labeled chymotryptic fragment of the peptide (d10-ASLW) as IS. Although this IS does not correct for variations in digestion recovery, it allows the selective quantification of enfuvirtide (100-10,000 ng/ml), besides the quantification of the sum of enfuvirtide and its de-amidated metabolite M-20 (120-12,000 ng/ml). Both methods were suitable for the absolute quantification of enfuvirtide and M-20 in plasma, but proper selection of the fragment(s) used for the quantification appeared crucial when the deuterated fragment was used as IS.
Collapse
Affiliation(s)
- Irene van den Broek
- Department of Pharmaceutical Sciences, Section of Biomedical Analysis, Division of Drug Toxicology, Utrecht University, Sorbonnelaan 16, 3584 CA Utrecht, The Netherlands.
| | | | | | | |
Collapse
|
18
|
Czerwenka C, Maier I, Potocnik N, Pittner F, Lindner W. Absolute Quantitation of β-Lactoglobulin by Protein Liquid Chromatography−Mass Spectrometry and Its Application to Different Milk Products. Anal Chem 2007; 79:5165-72. [PMID: 17555294 DOI: 10.1021/ac062367d] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The absolute quantitation of proteins in biological matrixes is of great interest in many fields and can be accomplished by different methodologies. Here, a method for the absolute quantitation of the whey protein beta-lactoglobulin using protein liquid chromatography coupled to mass spectrometry is reported. The developed approach was characterized in detail and applied to the determination of beta-lactoglobulin contents in various milk products. A special focus was placed on the recovery rates of the isolation procedure and on robust quantitation by LC-MS. For these purposes protein internal standards were employed. The observed recovery rates of beta-lactoglobulin from various samples ranged from 100% for whole milk to just over 50% for a strongly processed yogurt-based baby food product. The influence of processing was investigated in greater detail, showing that an increasing intensity of the applied heat treatment resulted in an increasing loss of beta-lactoglobulin. LC-MS quantitation at the protein level proved to be highly suitable, avoiding a potentially problematic digestion step. The use of an appropriate internal standard to compensate for sample losses during sample workup was shown to be essential for obtaining accurate results.
Collapse
Affiliation(s)
- Christoph Czerwenka
- Institute of Analytical Chemistry and Food Chemistry, University of Vienna, Währinger Strasse 38, 1090 Wien, Austria.
| | | | | | | | | |
Collapse
|
19
|
Whiteaker JR, Zhao L, Zhang HY, Feng LC, Piening BD, Anderson L, Paulovich AG. Antibody-based enrichment of peptides on magnetic beads for mass-spectrometry-based quantification of serum biomarkers. Anal Biochem 2006; 362:44-54. [PMID: 17241609 PMCID: PMC1852426 DOI: 10.1016/j.ab.2006.12.023] [Citation(s) in RCA: 236] [Impact Index Per Article: 13.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2006] [Revised: 12/05/2006] [Accepted: 12/12/2006] [Indexed: 12/17/2022]
Abstract
A major bottleneck for validation of new clinical diagnostics is the development of highly sensitive and specific assays for quantifying proteins. We previously described a method, stable isotope standards with capture by antipeptide antibodies, wherein a specific tryptic peptide is selected as a stoichiometric representative of the protein from which it is cleaved, is enriched from biological samples using immobilized antibodies, and is quantitated using mass spectrometry against a spiked internal standard to yield a measure of protein concentration. In this study, we optimized a magnetic-bead-based platform amenable to high-throughput peptide capture and demonstrated that antibody capture followed by mass spectrometry can achieve ion signal enhancements on the order of 10(3), with precision (CVs <10%) and accuracy (relative error approximately 20%) sufficient for quantifying biomarkers in the physiologically relevant ng/mL range. These methods are generally applicable to any protein or biological fluid of interest and hold great potential for providing a desperately needed bridging technology between biomarker discovery and clinical application.
Collapse
Affiliation(s)
- Jeffrey R Whiteaker
- Fred Hutchinson Cancer Research Center, 1100 Fairview Avenue N., PO Box 19024, Seattle, WA 98109-1024, USA
| | | | | | | | | | | | | |
Collapse
|