1
|
Hevér H, Xue A, Nagy K, Komka K, Vékey K, Drahos L, Révész Á. Can We Boost N-Glycopeptide Identification Confidence? Smart Collision Energy Choice Taking into Account Structure and Search Engine. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2024; 35:333-343. [PMID: 38286027 PMCID: PMC10853973 DOI: 10.1021/jasms.3c00375] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/27/2023] [Revised: 12/22/2023] [Accepted: 01/04/2024] [Indexed: 01/31/2024]
Abstract
High confidence and reproducibility are still challenges in bottom-up mass spectrometric N-glycopeptide identification. The collision energy used in the MS/MS measurements and the database search engine used to identify the species are perhaps the two most decisive factors. We investigated how the structural features of N-glycopeptides and the choice of the search engine influence the optimal collision energy, delivering the highest identification confidence. We carried out LC-MS/MS measurements using a series of collision energies on a large set of N-glycopeptides with both the glycan and peptide part varied and studied the behavior of Byonic, pGlyco, and GlycoQuest scores. We found that search engines show a range of behavior between peptide-centric and glycan-centric, which manifests itself already in the dependence of optimal collision energy on m/z. Using classical statistical and machine learning methods, we revealed that peptide hydrophobicity, glycan and peptide masses, and the number of mobile protons also have significant and search-engine-dependent influence, as opposed to a series of other parameters we probed. We envisioned an MS/MS workflow making a smart collision energy choice based on online available features such as the hydrophobicity (described by retention time) and glycan mass (potentially available from a scout MS/MS). Our assessment suggests that this workflow can lead to a significant gain (up to 100%) in the identification confidence, particularly for low-scoring hits close to the filtering limit, which has the potential to enhance reproducibility of N-glycopeptide analyses. Data are available via MassIVE (MSV000093110).
Collapse
Affiliation(s)
- Helga Hevér
- MS
Proteomics Research Group, HUN-REN Research
Centre for Natural Sciences, Magyar Tudósok körútja 2., Budapest H-1117, Hungary
| | - Andrea Xue
- MS
Proteomics Research Group, HUN-REN Research
Centre for Natural Sciences, Magyar Tudósok körútja 2., Budapest H-1117, Hungary
| | - Kinga Nagy
- MS
Proteomics Research Group, HUN-REN Research
Centre for Natural Sciences, Magyar Tudósok körútja 2., Budapest H-1117, Hungary
- Faculty
of Science, Institute of Chemistry, Hevesy György PhD School
of Chemistry, Eötvös Loránd
University, Pázmány
Péter sétány 1/A, Budapest H-1117, Hungary
| | - Kinga Komka
- Department
of Chemical and Environmental Process Engineering, Budapest University of Technology and Economics, Budapest H-1111, Hungary
| | - Károly Vékey
- MS
Proteomics Research Group, HUN-REN Research
Centre for Natural Sciences, Magyar Tudósok körútja 2., Budapest H-1117, Hungary
| | - László Drahos
- MS
Proteomics Research Group, HUN-REN Research
Centre for Natural Sciences, Magyar Tudósok körútja 2., Budapest H-1117, Hungary
| | - Ágnes Révész
- MS
Proteomics Research Group, HUN-REN Research
Centre for Natural Sciences, Magyar Tudósok körútja 2., Budapest H-1117, Hungary
| |
Collapse
|
2
|
Szabó D, Gömöry Á, Ludányi K, Vékey K, Drahos L. Very Low-Pressure CID Experiments: High Energy Transfer and Fragmentation Pattern at the Single Collision Regime. Molecules 2023; 29:211. [PMID: 38202794 PMCID: PMC10780993 DOI: 10.3390/molecules29010211] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2023] [Revised: 12/20/2023] [Accepted: 12/25/2023] [Indexed: 01/12/2024] Open
Abstract
We have performed CID experiments on a triple quadrupole instrument, lowering the collision gas pressure by 50 times compared to its conventional value. The results show that at very low-collision gas pressure, single collisions dominate the spectra. Indirectly, these results suggest that under conventional conditions, 20-50 collisions may be typical in CID experiments. The results show a marked difference between low- and high-pressure CID spectra, the latter being characterized in terms of 'slow heating' and predominance of consecutive reactions. The results indicate that under single collision conditions, the collisional energy transfer efficiency is very high: nearly 100% of the center of mass kinetic energy is converted to internal energy.
Collapse
Affiliation(s)
- Dániel Szabó
- MS Proteomics Research Group, HUN-REN Research Centre for Natural Sciences, H-1117 Budapest, Hungary (Á.G.); (K.V.)
| | - Ágnes Gömöry
- MS Proteomics Research Group, HUN-REN Research Centre for Natural Sciences, H-1117 Budapest, Hungary (Á.G.); (K.V.)
| | - Krisztina Ludányi
- Department of Pharmaceutics, Semmelweis University, Hőgyes Endre 7–9, H-1092 Budapest, Hungary;
| | - Károly Vékey
- MS Proteomics Research Group, HUN-REN Research Centre for Natural Sciences, H-1117 Budapest, Hungary (Á.G.); (K.V.)
| | - László Drahos
- MS Proteomics Research Group, HUN-REN Research Centre for Natural Sciences, H-1117 Budapest, Hungary (Á.G.); (K.V.)
| |
Collapse
|
3
|
Nagy K, Gellén G, Papp D, Schlosser G, Révész Á. Optimum collision energies for proteomics: The impact of ion mobility separation. JOURNAL OF MASS SPECTROMETRY : JMS 2023; 58:e4957. [PMID: 37415399 DOI: 10.1002/jms.4957] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/22/2022] [Revised: 05/28/2023] [Accepted: 06/19/2023] [Indexed: 07/08/2023]
Abstract
Ion mobility spectrometry (IMS) is a widespread separation technique used in various research fields. It can be coupled to liquid chromatography-mass spectrometry (LC-MS/MS) methods providing an additional separation dimension. During IMS, ions are subjected to multiple collisions with buffer gas, which may cause significant ion heating. The present project addresses this phenomenon from the bottom-up proteomics point of view. We performed LC-MS/MS measurements on a cyclic ion mobility mass spectrometer with varied collision energy (CE) settings both with and without IMS. We investigated the CE dependence of identification score, using Byonic search engine, for more than 1000 tryptic peptides from HeLa digest standard. We determined the optimal CE values-giving the highest identification score-for both setups (i.e., with and without IMS). Results show that lower CE is advantageous when IMS separation is applied, by 6.3 V on average. This value belongs to the one-cycle separation configuration, and multiple cycles may supposedly have even larger impact. The effect of IMS is also reflected in the trends of optimal CE values versus m/z functions. The parameters suggested by the manufacturer were found to be almost optimal for the setup without IMS; on the other hand, they are obviously too high with IMS. Practical consideration on setting up a mass spectrometric platform hyphenated to IMS is also presented. Furthermore, the two CID (collision induced dissociation) fragmentation cells of the instrument-located before and after the IMS cell-were also compared, and we found that CE adjustment is needed when the trap cell is used for activation instead of the transfer cell. Data have been deposited in the MassIVE repository (MSV000090944).
Collapse
Affiliation(s)
- Kinga Nagy
- MS Proteomics Research Group, Research Centre for Natural Sciences, Budapest, H-1117, Hungary
- Hevesy György PhD School of Chemistry, Faculty of Science, Institute of Chemistry, Eötvös Loránd University, Budapest, H-1117, Hungary
| | - Gabriella Gellén
- MTA-ELTE Lendület Ion Mobility Mass Spectrometry Research Group, Faculty of Science, Institute of Chemistry, Eötvös Loránd University, Budapest, H-1117, Hungary
| | - Dávid Papp
- Hevesy György PhD School of Chemistry, Faculty of Science, Institute of Chemistry, Eötvös Loránd University, Budapest, H-1117, Hungary
- MTA-ELTE Lendület Ion Mobility Mass Spectrometry Research Group, Faculty of Science, Institute of Chemistry, Eötvös Loránd University, Budapest, H-1117, Hungary
| | - Gitta Schlosser
- MTA-ELTE Lendület Ion Mobility Mass Spectrometry Research Group, Faculty of Science, Institute of Chemistry, Eötvös Loránd University, Budapest, H-1117, Hungary
| | - Ágnes Révész
- MS Proteomics Research Group, Research Centre for Natural Sciences, Budapest, H-1117, Hungary
| |
Collapse
|
4
|
Révész Á, Hevér H, Steckel A, Schlosser G, Szabó D, Vékey K, Drahos L. Collision energies: Optimization strategies for bottom-up proteomics. MASS SPECTROMETRY REVIEWS 2023; 42:1261-1299. [PMID: 34859467 DOI: 10.1002/mas.21763] [Citation(s) in RCA: 12] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/11/2021] [Revised: 11/17/2021] [Accepted: 11/17/2021] [Indexed: 06/07/2023]
Abstract
Mass-spectrometry coupled to liquid chromatography is an indispensable tool in the field of proteomics. In the last decades, more and more complex and diverse biochemical and biomedical questions have arisen. Problems to be solved involve protein identification, quantitative analysis, screening of low abundance modifications, handling matrix effect, and concentrations differing by orders of magnitude. This led the development of more tailored protocols and problem centered proteomics workflows, including advanced choice of experimental parameters. In the most widespread bottom-up approach, the choice of collision energy in tandem mass spectrometric experiments has outstanding role. This review presents the collision energy optimization strategies in the field of proteomics which can help fully exploit the potential of MS based proteomics techniques. A systematic collection of use case studies is then presented to serve as a starting point for related further scientific work. Finally, this article discusses the issue of comparing results from different studies or obtained on different instruments, and it gives some hints on methodology transfer between laboratories based on measurement of reference species.
Collapse
Affiliation(s)
- Ágnes Révész
- MS Proteomics Research Group, Institute of Organic Chemistry, Research Centre for Natural Sciences, Budapest, Hungary
| | - Helga Hevér
- Chemical Works of Gedeon Richter Plc, Budapest, Hungary
| | - Arnold Steckel
- Department of Analytical Chemistry, MTA-ELTE Lendület Ion Mobility Mass Spectrometry Research Group, Institute of Chemistry, ELTE Eötvös Loránd University, Budapest, Hungary
| | - Gitta Schlosser
- Department of Analytical Chemistry, MTA-ELTE Lendület Ion Mobility Mass Spectrometry Research Group, Institute of Chemistry, ELTE Eötvös Loránd University, Budapest, Hungary
| | - Dániel Szabó
- MS Proteomics Research Group, Institute of Organic Chemistry, Research Centre for Natural Sciences, Budapest, Hungary
| | - Károly Vékey
- MS Proteomics Research Group, Institute of Organic Chemistry, Research Centre for Natural Sciences, Budapest, Hungary
| | - László Drahos
- MS Proteomics Research Group, Institute of Organic Chemistry, Research Centre for Natural Sciences, Budapest, Hungary
| |
Collapse
|
5
|
Hevér H, Nagy K, Xue A, Sugár S, Komka K, Vékey K, Drahos L, Révész Á. Diversity Matters: Optimal Collision Energies for Tandem Mass Spectrometric Analysis of a Large Set of N-Glycopeptides. J Proteome Res 2022; 21:2743-2753. [PMID: 36201757 DOI: 10.1021/acs.jproteome.2c00519] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Identification and characterization of N-glycopeptides from complex samples are usually based on tandem mass spectrometric measurements. Experimental settings, especially the collision energy selection method, fundamentally influence the obtained fragmentation pattern and hence the confidence of the database search results ("score"). Using standards of naturally occurring glycoproteins, we mapped the Byonic and pGlyco search engine scores of almost 200 individual N-glycopeptides as a function of collision energy settings on a quadrupole time of flight instrument. The resulting unprecedented amount of peptide-level information on such a large and diverse set of N-glycopeptides revealed that the peptide sequence heavily influences the energy for the highest score on top of an expected general linear trend with m/z. Search engine dependence may also be noteworthy. Based on the trends, we designed an experimental method and tested it on HeLa, blood plasma, and monoclonal antibody samples. As compared to the literature, these notably lower collision energies in our workflow led to 10-50% more identified N-glycopeptides, with higher scores. We recommend a simple approach based on a small set of reference N-glycopeptides easily accessible from glycoprotein standards to ease the precise determination of optimal methods on other instruments. Data sets can be accessed via the MassIVE repository (MSV000089657 and MSV000090218).
Collapse
Affiliation(s)
- Helga Hevér
- MS Proteomics Research Group, Eötvös Loránd Research Network, Research Centre for Natural Sciences, Magyar Tudósok körútja 2, Budapest H-1117, Hungary.,Chemical Works of Gedeon Richter Plc, Gyömríi út 19-21, Budapest 1103, Hungary
| | - Kinga Nagy
- MS Proteomics Research Group, Eötvös Loránd Research Network, Research Centre for Natural Sciences, Magyar Tudósok körútja 2, Budapest H-1117, Hungary.,Hevesy György PhD School of Chemistry, Faculty of Science, Institute of Chemistry, Eötvös Loránd University, Pázmány Péter sétány 1/A, Budapest H-1117, Hungary
| | - Andrea Xue
- MS Proteomics Research Group, Eötvös Loránd Research Network, Research Centre for Natural Sciences, Magyar Tudósok körútja 2, Budapest H-1117, Hungary
| | - Simon Sugár
- MS Proteomics Research Group, Eötvös Loránd Research Network, Research Centre for Natural Sciences, Magyar Tudósok körútja 2, Budapest H-1117, Hungary
| | - Kinga Komka
- Department of Chemical and Environmental Process Engineering, Budapest University of Technology and Economics, Budapest H-1111, Hungary
| | - Károly Vékey
- MS Proteomics Research Group, Eötvös Loránd Research Network, Research Centre for Natural Sciences, Magyar Tudósok körútja 2, Budapest H-1117, Hungary
| | - László Drahos
- MS Proteomics Research Group, Eötvös Loránd Research Network, Research Centre for Natural Sciences, Magyar Tudósok körútja 2, Budapest H-1117, Hungary
| | - Ágnes Révész
- MS Proteomics Research Group, Eötvös Loránd Research Network, Research Centre for Natural Sciences, Magyar Tudósok körútja 2, Budapest H-1117, Hungary
| |
Collapse
|
6
|
Steckel A, Révész Á, Papp D, Uray K, Drahos L, Schlosser G. Stepwise Collision Energy-Resolved Tandem Mass Spectrometric Experiments for the Improved Identification of Citrullinated Peptides. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2022; 33:1176-1186. [PMID: 35621259 DOI: 10.1021/jasms.2c00031] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
The use of tandem mass spectrometry (MS/MS) is a fundamental prerequisite of reliable protein identification and quantification in mass-spectrometry-based proteomics. In bottom-up and middle-down proteomics, proteins are identified by the characteristic fragments of their constituting peptides. Post-translational modifications (PTMs) often further complicate proteome analyses. Citrullination is an increasingly studied PTM converting arginines to citrullines (Cit, X) and is implicated in several autoimmune and neurological diseases as well as different types of cancer. Confirmation of citrullination is known to be very challenging since it results in the same molecular mass change as Asn/Gln deamidation. In this study, we explore which MS/MS characteristics can be used for the reliable identification of citrullination. We synthesized several peptides incorporating Cit residues that model enzymatic cleavages of different proteins with verified or putative citrullination. Collision-induced dissociation was used to investigate the energy dependence of Byonic and Mascot scores and confirmed sequence coverage (CSC) along with the neutral loss of HNCO characteristic to citrulline side chains. We found that although the recommended values (19-45 V) for ramped collision energy settings cover the optimal Mascot, Byonic, or %CSC scores effectively, the diagnostic HNCO loss from precursors and fragments may reach their maximum intensities at lower and higher collision energies, respectively. Therefore, we suggest broadening the ramp range to ∼5-60 V to obtain more favorable identification rates for citrullinated peptides. We also found that Byonic was more successful in correctly identifying citrullinated peptides with deamidated residues than Mascot.
Collapse
Affiliation(s)
- Arnold Steckel
- MTA-ELTE Lendület Ion Mobility Mass Spectrometry Research Group, ELTE Eötvös Loránd University, Institute of Chemistry, Department of Analytical Chemistry, Pázmány Péter sétány 1/A, 1117 Budapest, Hungary
| | - Ágnes Révész
- Research Centre for Natural Sciences, MS Proteomics Research Group, Magyar tudósok körútja 2, 1117 Budapest, Hungary
| | - Dávid Papp
- MTA-ELTE Lendület Ion Mobility Mass Spectrometry Research Group, ELTE Eötvös Loránd University, Institute of Chemistry, Department of Analytical Chemistry, Pázmány Péter sétány 1/A, 1117 Budapest, Hungary
- Hevesy György PhD School of Chemistry, ELTE Eötvös Loránd University, Pázmány Péter sétány 1/A, 1117 Budapest, Hungary
| | - Katalin Uray
- MTA-ELTE Research Group of Peptide Chemistry, Eötvös Loránd Research Network (ELKH), ELTE Eötvös Loránd University, Pázmány Péter sétány 1/A, 1117 Budapest, Hungary
| | - László Drahos
- Research Centre for Natural Sciences, MS Proteomics Research Group, Magyar tudósok körútja 2, 1117 Budapest, Hungary
| | - Gitta Schlosser
- MTA-ELTE Lendület Ion Mobility Mass Spectrometry Research Group, ELTE Eötvös Loránd University, Institute of Chemistry, Department of Analytical Chemistry, Pázmány Péter sétány 1/A, 1117 Budapest, Hungary
| |
Collapse
|
7
|
Szabó D, Schlosser G, Vékey K, Drahos L, Révész Á. Collision energies on QTof and Orbitrap instruments: How to make proteomics measurements comparable? JOURNAL OF MASS SPECTROMETRY : JMS 2021; 56:e4693. [PMID: 33277714 DOI: 10.1002/jms.4693] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/24/2020] [Revised: 11/23/2020] [Accepted: 11/24/2020] [Indexed: 06/12/2023]
Abstract
Quadrupole time-of-flight (QTof) collision-induced dissociation (CID) and Orbitrap higher-energy collisional dissociation (HCD) are the most commonly used fragmentation techniques in mass spectrometry-based proteomics workflows. The information content of the MS/MS spectra is first and foremost determined by the applied collision energy. How can we set up the two instrument types to achieve maximum transferability? To answer this question, we compared MS/MS spectra obtained on a Bruker QTof CID and a Thermo Q-Exactive Focus Orbitrap HCD instrument as a function of collision energy using the similarity index. Results show that with a few eV lower collision energy setting on HCD (Orbitrap-specific CID) than on QTof CID, nearly identical MS/MS spectra can be obtained for leucine enkephalin pentapeptide standard, for selected +2 and +3 enolase tryptic peptides and for a large number of peptides in a HeLa protein digest. The Bruker QTof was able to produce colder ions, which may be significant to study inherently labile compounds. Further, we examined energy dependence of peptide identification confidence, as characterized by Mascot scores, on the HeLa peptides. In line with earlier QTof results, this dependence shows one or two maxima (unimodal or bimodal behavior) on Orbitrap. The fraction of bimodal peptides is lower on Orbitrap. Optimal energies as a function of m/z show a similar linear trend on both instruments, which suggests that with appropriate collision energy adjustment, matching conditions for proteomics can be achieved. Data have been deposited in the MassIVE repository (MSV000086434).
Collapse
Affiliation(s)
- Dániel Szabó
- MS Proteomics Research Group, Research Centre for Natural Sciences, Magyar Tudósok körútja 2., Budapest, H-1117, Hungary
- Hevesy György PhD School of Chemistry, Eötvös Loránd University, Faculty of Science, Institute of Chemistry, Pázmány Péter sétány 1/A, Budapest, H-1117, Hungary
| | - Gitta Schlosser
- MTA-ELTE Lendület Ion Mobility Mass Spectrometry Research Group, Eötvös Loránd University, Faculty of Science, Institute of Chemistry, Pázmány Péter sétány 1/A, Budapest, H-1117, Hungary
| | - Károly Vékey
- MS Proteomics Research Group, Research Centre for Natural Sciences, Magyar Tudósok körútja 2., Budapest, H-1117, Hungary
| | - László Drahos
- MS Proteomics Research Group, Research Centre for Natural Sciences, Magyar Tudósok körútja 2., Budapest, H-1117, Hungary
| | - Ágnes Révész
- MS Proteomics Research Group, Research Centre for Natural Sciences, Magyar Tudósok körútja 2., Budapest, H-1117, Hungary
| |
Collapse
|
8
|
Révész Á, Milley MG, Nagy K, Szabó D, Kalló G, Csősz É, Vékey K, Drahos L. Tailoring to Search Engines: Bottom-Up Proteomics with Collision Energies Optimized for Identification Confidence. J Proteome Res 2020; 20:474-484. [PMID: 33284634 PMCID: PMC7786379 DOI: 10.1021/acs.jproteome.0c00518] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
![]()
Bottom-up
proteomics relies on identification of peptides from
tandem mass spectra, usually via matching against sequence databases.
Confidence in a peptide–spectrum match can be characterized
by a score value given by the database search engines, and it depends
on the information content and the quality of the spectrum. The latter
are influenced by experimental parameters, of which the collision
energy is the most important one in the case of collision-induced
dissociation. We examined how the identification score of the Byonic
and Andromeda (MaxQuant) engines varies with collision energy for
more than a thousand individual peptides from a HeLa tryptic digest
on a QTof instrument. We thereby extended our earlier study on Mascot
scores and corroborated its findings on the potential bimodal nature
of this energy dependence. Optimal energies as a function of m/z show comparable linear trends for the
three engines. On the basis of peptide-level results, we designed
methods with one or two liquid chromatography–tandem mass spectrometry
(LC-MS/MS) runs and various collision energy settings and assessed
their practical performance in peptide and protein identification
from the HeLa standard sample. A 10–40% gain in various measures,
such as the number of identified proteins or sequence coverage, was
obtained over the factory default settings. Best performing methods
differ for the three engines, suggesting that the experimental parameters
should be fine-tuned to the choice of the engine. We also recommend
a simple approach and provide reference data to ease the transfer
of the optimized methods to other mass spectrometers relevant for
proteomics. We demonstrate the utility of this approach on an Orbitrap
instrument. Data sets can be accessed via the MassIVE repository (MSV000086379).
Collapse
Affiliation(s)
- Ágnes Révész
- MS Proteomics Research Group, Research Centre for Natural Sciences, Magyar Tudósok Körútja 2, H-1117 Budapest, Hungary
| | - Márton Gyula Milley
- MS Proteomics Research Group, Research Centre for Natural Sciences, Magyar Tudósok Körútja 2, H-1117 Budapest, Hungary
| | - Kinga Nagy
- MS Proteomics Research Group, Research Centre for Natural Sciences, Magyar Tudósok Körútja 2, H-1117 Budapest, Hungary
| | - Dániel Szabó
- MS Proteomics Research Group, Research Centre for Natural Sciences, Magyar Tudósok Körútja 2, H-1117 Budapest, Hungary.,Faculty of Science, Institute of Chemistry, Hevesy György PhD School of Chemistry, ELTE, Eötvös Loránd University, Pázmány Péter Sétány 1/A, H-1117 Budapest, Hungary
| | - Gergő Kalló
- Department of Biochemistry and Molecular Biology, Faculty of Medicine, University of Debrecen, Egyetem tér 1, 4032 Debrecen, Hungary
| | - Éva Csősz
- Department of Biochemistry and Molecular Biology, Faculty of Medicine, University of Debrecen, Egyetem tér 1, 4032 Debrecen, Hungary
| | - Károly Vékey
- MS Proteomics Research Group, Research Centre for Natural Sciences, Magyar Tudósok Körútja 2, H-1117 Budapest, Hungary
| | - László Drahos
- MS Proteomics Research Group, Research Centre for Natural Sciences, Magyar Tudósok Körútja 2, H-1117 Budapest, Hungary
| |
Collapse
|