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Virág D, Schlosser G, Borbély A, Gellén G, Papp D, Kaleta Z, Dalmadi-Kiss B, Antal I, Ludányi K. A Mass Spectrometry Strategy for Protein Quantification Based on the Differential Alkylation of Cysteines Using Iodoacetamide and Acrylamide. Int J Mol Sci 2024; 25:4656. [PMID: 38731875 PMCID: PMC11083099 DOI: 10.3390/ijms25094656] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2024] [Revised: 04/15/2024] [Accepted: 04/21/2024] [Indexed: 05/13/2024] Open
Abstract
Mass spectrometry has become the most prominent yet evolving technology in quantitative proteomics. Today, a number of label-free and label-based approaches are available for the relative and absolute quantification of proteins and peptides. However, the label-based methods rely solely on the employment of stable isotopes, which are expensive and often limited in availability. Here we propose a label-based quantification strategy, where the mass difference is identified by the differential alkylation of cysteines using iodoacetamide and acrylamide. The alkylation reactions were performed under identical experimental conditions; therefore, the method can be easily integrated into standard proteomic workflows. Using high-resolution mass spectrometry, the feasibility of this approach was assessed with a set of tryptic peptides of human serum albumin. Several critical questions, such as the efficiency of labeling and the effect of the differential alkylation on the peptide retention and fragmentation, were addressed. The concentration of the quality control samples calculated against the calibration curves were within the ±20% acceptance range. It was also demonstrated that heavy labeled peptides exhibit a similar extraction recovery and matrix effect to light ones. Consequently, the approach presented here may be a viable and cost-effective alternative of stable isotope labeling strategies for the quantification of cysteine-containing proteins.
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Affiliation(s)
- Dávid Virág
- Department of Pharmaceutics, Semmelweis University, Hőgyes Endre utca 7., H-1092 Budapest, Hungary; (D.V.); (B.D.-K.); (I.A.)
| | - Gitta Schlosser
- MTA-ELTE Lendület Ion Mobility Mass Spectrometry Research Group, Institute of Chemistry, Faculty of Science, ELTE Eötvös Loránd University, Pázmány Péter sétány 1/A, H-1117 Budapest, Hungary; (G.S.); (A.B.); (G.G.); (D.P.)
| | - Adina Borbély
- MTA-ELTE Lendület Ion Mobility Mass Spectrometry Research Group, Institute of Chemistry, Faculty of Science, ELTE Eötvös Loránd University, Pázmány Péter sétány 1/A, H-1117 Budapest, Hungary; (G.S.); (A.B.); (G.G.); (D.P.)
| | - Gabriella Gellén
- MTA-ELTE Lendület Ion Mobility Mass Spectrometry Research Group, Institute of Chemistry, Faculty of Science, ELTE Eötvös Loránd University, Pázmány Péter sétány 1/A, H-1117 Budapest, Hungary; (G.S.); (A.B.); (G.G.); (D.P.)
| | - Dávid Papp
- MTA-ELTE Lendület Ion Mobility Mass Spectrometry Research Group, Institute of Chemistry, Faculty of Science, ELTE Eötvös Loránd University, Pázmány Péter sétány 1/A, H-1117 Budapest, Hungary; (G.S.); (A.B.); (G.G.); (D.P.)
- Hevesy György PhD School of Chemistry, Institute of Chemistry, ELTE Eötvös Loránd University, Pázmány Péter sétány 1/A, H-1117 Budapest, Hungary
| | - Zoltán Kaleta
- Department of Organic Chemistry, Semmelweis University, Hőgyes Endre utca 7., H-1092 Budapest, Hungary;
| | - Borbála Dalmadi-Kiss
- Department of Pharmaceutics, Semmelweis University, Hőgyes Endre utca 7., H-1092 Budapest, Hungary; (D.V.); (B.D.-K.); (I.A.)
| | - István Antal
- Department of Pharmaceutics, Semmelweis University, Hőgyes Endre utca 7., H-1092 Budapest, Hungary; (D.V.); (B.D.-K.); (I.A.)
| | - Krisztina Ludányi
- Department of Pharmaceutics, Semmelweis University, Hőgyes Endre utca 7., H-1092 Budapest, Hungary; (D.V.); (B.D.-K.); (I.A.)
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2
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Wong FC, Chai TT. Bioactive Peptides and Protein Hydrolysates as Lipoxygenase Inhibitors. BIOLOGY 2023; 12:917. [PMID: 37508348 PMCID: PMC10376772 DOI: 10.3390/biology12070917] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/03/2023] [Revised: 06/15/2023] [Accepted: 06/19/2023] [Indexed: 07/30/2023]
Abstract
Lipoxygenases are non-heme iron-containing enzymes that catalyze the oxidation of polyunsaturated fatty acids, resulting in the production of lipid hydroperoxides, which are precursors of inflammatory lipid mediators. These enzymes are widely distributed in humans, other eukaryotes, and cyanobacteria. Lipoxygenases hold promise as therapeutic targets for several human diseases, including cancer and inflammation-related disorders. Inhibitors of lipoxygenase have potential applications in pharmaceuticals, cosmetics, and food. Bioactive peptides are short amino acid sequences embedded within parent proteins, which can be released by enzymatic hydrolysis, microbial fermentation, and gastrointestinal digestion. A wide variety of bioactivities have been documented for protein hydrolysates and peptides derived from different biological sources. Recent findings indicate that protein hydrolysates and peptides derived from both edible and non-edible bioresources can act as lipoxygenase inhibitors. This review aims to provide an overview of the current knowledge regarding the production of anti-lipoxygenase protein hydrolysates and peptides from millet grains, chia seeds, insects, milk proteins, fish feed, velvet antler blood, fish scales, and feather keratins. The anti-lipoxygenase activities and modes of action of these protein hydrolysates and peptides are discussed. The strengths and shortcomings of previous research in this area are emphasized. Additionally, potential research directions and areas for improvement are suggested to accelerate the discovery of anti-lipoxygenase peptides in the near future.
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Affiliation(s)
- Fai-Chu Wong
- Department of Chemical Science, Faculty of Science, Universiti Tunku Abdul Rahman, Kampar 31900, Malaysia
- Center for Agriculture and Food Research, Universiti Tunku Abdul Rahman, Kampar 31900, Malaysia
| | - Tsun-Thai Chai
- Department of Chemical Science, Faculty of Science, Universiti Tunku Abdul Rahman, Kampar 31900, Malaysia
- Center for Agriculture and Food Research, Universiti Tunku Abdul Rahman, Kampar 31900, Malaysia
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3
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Filippova TA, Masamrekh RA, Shumyantseva VV, Latsis IA, Farafonova TE, Ilina IY, Kanashenko SL, Moshkovskii SA, Kuzikov AV. Electrochemical biosensor for trypsin activity assay based on cleavage of immobilized tyrosine-containing peptide. Talanta 2023; 257:124341. [PMID: 36821964 DOI: 10.1016/j.talanta.2023.124341] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2022] [Revised: 01/13/2023] [Accepted: 02/09/2023] [Indexed: 02/16/2023]
Abstract
In this work, we proposed a biosensor for trypsin proteolytic activity assay using immobilization of model peptides on screen-printed electrodes (SPE) modified with gold nanoparticles (AuNPs) prepared by electrosynthetic method. Sensing of proteolytic activity was based on electrochemical oxidation of tyrosine residues of peptides. We designed peptides containing N-terminal cysteine residue for immobilization on an SPE, modified with gold nanoparticles, trypsin-specific cleavage site and tyrosine residue as a redox label. The peptides were immobilized on SPE by formation of chemical bonds between mercapto groups of the N-terminal cysteine residues and AuNPs. After the incubation with trypsin, time-dependent cleavage of the immobilized peptides was observed by decline in tyrosine electrochemical oxidation signal. The kinetic parameters of trypsin, such as the catalytic constant (kcat), the Michaelis constant (KM) and the catalytic efficiency (kcat/KM), toward the CGGGRYR peptide were determined as 0.33 ± 0.01 min-1, 198 ± 24 nM and 0.0016 min-1 nM-1, respectively. Using the developed biosensor, we demonstrated the possibility of analysis of trypsin specificity toward the peptides with amino acid residues disrupting proteolysis. Further, we designed the peptides with proline or glutamic acid residues after the cleavage site (CGGRPYR and CGGREYR), and trypsin had reduced activity toward both of them according to the existing knowledge of the enzyme specificity. The developed biosensor system allows one to perform a comparative analysis of the protease steady-state kinetic parameters and specificity toward model peptides with different amino acid sequences.
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Affiliation(s)
- Tatiana A Filippova
- Pirogov Russian National Research Medical University, 1 Ostrovityanova st., Moscow 117997, Russia; Institute of Biomedical Chemistry, 10, Pogodinskaya st., Moscow, 119121, Russia
| | - Rami A Masamrekh
- Pirogov Russian National Research Medical University, 1 Ostrovityanova st., Moscow 117997, Russia; Institute of Biomedical Chemistry, 10, Pogodinskaya st., Moscow, 119121, Russia
| | - Victoria V Shumyantseva
- Pirogov Russian National Research Medical University, 1 Ostrovityanova st., Moscow 117997, Russia; Institute of Biomedical Chemistry, 10, Pogodinskaya st., Moscow, 119121, Russia
| | - Ivan A Latsis
- Federal Research and Clinical Center of Physical-Chemical Medicine, 1a Malaya Pirogovskaya st., Moscow, 119435, Russia
| | | | - Irina Y Ilina
- Federal Research and Clinical Center of Physical-Chemical Medicine, 1a Malaya Pirogovskaya st., Moscow, 119435, Russia
| | - Sergey L Kanashenko
- Institute of Biomedical Chemistry, 10, Pogodinskaya st., Moscow, 119121, Russia
| | - Sergei A Moshkovskii
- Pirogov Russian National Research Medical University, 1 Ostrovityanova st., Moscow 117997, Russia; Federal Research and Clinical Center of Physical-Chemical Medicine, 1a Malaya Pirogovskaya st., Moscow, 119435, Russia.
| | - Alexey V Kuzikov
- Pirogov Russian National Research Medical University, 1 Ostrovityanova st., Moscow 117997, Russia; Institute of Biomedical Chemistry, 10, Pogodinskaya st., Moscow, 119121, Russia.
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4
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Khani M, Hansen MF, Knøchel S, Rasekh B, Ghasemipanah K, Zamir SM, Nosrati M, Burmølle M. Antifouling potential of enzymes applied to Reverse Osmosis Membranes. Biofilm 2023; 5:100119. [PMID: 37131492 PMCID: PMC10149195 DOI: 10.1016/j.bioflm.2023.100119] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2022] [Revised: 03/31/2023] [Accepted: 03/31/2023] [Indexed: 04/03/2023] Open
Abstract
Many companies in the food industry apply reverse osmosis (RO) membranes to ensure high-quality reuse of water. Biofouling is however, a common, recalcitrant and recurring problem that blocks transport over membranes and decreases the water recovery. Microorganisms adhering to membranes may form biofilm and produce an extracellular matrix, which protects against external stress and ensures continuous attachment. Thus, various agents are tested for their ability to degrade and disperse biofilms. Here, we identified industrially relevant bacterial model communities that form biofilms on RO membranes used for treating process water before reuse. There was a marked difference in the biofilm forming capabilities of bacteria isolated from contaminated RO membranes. One species, Raoultella ornithinolytica, was particularly capable of forming biofilm and was included in most communities. The potential of different enzymes (Trypsin-EDTA, Proteinase K, α-Amylase, β-Mannosidase and Alginate lyase) as biofouling dispersing agents was evaluated at different concentrations (0.05 U/ml and 1.28 U/ml). Among the tested enzymes, β-Mannosidase was the only enzyme able to reduce biofilm formation significantly within 4 h of exposure at 25 °C (0.284 log reduction), and only at the high concentration. Longer exposure duration, however, resulted in significant biofilm reduction by all enzymes tested (0.459-0.717 log reduction) at both low and high concentrations. Using confocal laser scanning microscopy, we quantified the biovolume on RO membranes after treatment with two different enzyme mixtures. The application of proteinase K and β-Mannosidase significantly reduced the amount of attached biomass (43% reduction), and the combination of all five enzymes showed even stronger reducing effect (71% reduction). Overall, this study demonstrates a potential treatment strategy, using matrix-degrading enzymes for biofouled RO membranes in food processing water treatment streams. Future studies on optimization of buffer systems, temperature and other factors could facilitate cleaning operations based on enzymatic treatment extending the lifespan of membranes with a continuous flux.
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5
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Yang Y, Zhang F, Gan Y, Zhang HM, Liu P, Mah A, Gennaro L, Schöneich C. In-Depth Characterization of Acidic Variants Induced by Metal-Catalyzed Oxidation in a Recombinant Monoclonal Antibody. Anal Chem 2023; 95:5867-5876. [PMID: 36972215 DOI: 10.1021/acs.analchem.2c04414] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/29/2023]
Abstract
Characterization of antibody charge heterogeneity is an important task for antibody drug development. Recently, a correlation between acidic charge heterogeneity and metal-catalyzed oxidation has been observed for antibody drugs. However, to date, the acidic variants induced by metal-catalyzed oxidation have not been elucidated. In addition, it is challenging to satisfactorily explain the induced acidic charge heterogeneity, as the existing analytical workflows, which relied on either untargeted or targeted peptide mapping analysis, could lead to incomplete identification of the acidic variants. In this work, we present a new characterization workflow by combining untargeted and targeted analyses to thoroughly identify and characterize the induced acidic variants in a highly oxidized IgG1 antibody. As a part of this workflow, a tryptic peptide mapping method was also developed for accurate determination of the relative extent of site-specific carbonylation, where a new hydrazone reduction procedure was established to minimize under-quantitation artifacts caused by incomplete reduction of hydrazones during sample preparation. In summary, we identified 28 site-specific oxidation products, which are located on 26 residues and of 11 different modification types, as the sources of the induced acidic charge heterogeneity. Many of the oxidation products were reported for the first time in antibody drugs. More importantly, this study provides new insights to understanding acidic charge heterogeneity of antibody drugs in the biotechnology industry. Additionally, the characterization workflow presented in this study can be applied as a platform approach in the biotechnology industry to better address the need for in-depth characterization of antibody charge variants.
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Abstract
In-gel digestion of protein spots derived from two-dimensional gels and their subsequent identification by mass spectrometry is involved in a multitude of mass spectrometry-driven proteomic experiments, including fluorescence two-dimensional difference gel electrophoresis (2D-DIGE). This type of proteomic methodology has been involved in the establishment of comparative proteome maps and in the identification of differentially expressed proteins and their isoforms in health and disease. Most in-gel digestion protocols follow a number of common steps including excision of the protein spots of interest, destaining, reduction and alkylation (for silver-stained gels), and dehydration and overnight digestion with the proteolytic enzyme of choice. While trypsin has been a mainstay of peptide digestion for many years, it does have its shortcomings, particularly related to incomplete peptide digestion, and this has led to a rise in popularity for other proteolytic enzymes either used alone or in combination. This chapter discusses the alternative enzymes available and describes the process of in-gel digestion using the enzyme trypsin.
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Affiliation(s)
| | - Kay Ohlendieck
- Department of Biology, Maynooth University, National University of Ireland, Maynooth, Co. Kildare, Ireland.
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7
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Danko K, Lukasheva E, Zhukov VA, Zgoda V, Frolov A. Detergent-Assisted Protein Digestion-On the Way to Avoid the Key Bottleneck of Shotgun Bottom-Up Proteomics. Int J Mol Sci 2022; 23:13903. [PMID: 36430380 PMCID: PMC9695859 DOI: 10.3390/ijms232213903] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2022] [Revised: 11/02/2022] [Accepted: 11/05/2022] [Indexed: 11/16/2022] Open
Abstract
Gel-free bottom-up shotgun proteomics is the principal methodological platform for the state-of-the-art proteome research. This methodology assumes quantitative isolation of the total protein fraction from a complex biological sample, its limited proteolysis with site-specific proteases, analysis of the resulted peptides with nanoscaled reversed-phase high-performance liquid chromatography-(tandem) mass spectrometry (nanoRP-HPLC-MS and MS/MS), protein identification by sequence database search and peptide-based quantitative analysis. The most critical steps of this workflow are protein reconstitution and digestion; therefore, detergents and chaotropic agents are strongly mandatory to ensure complete solubilization of complex protein isolates and to achieve accessibility of all protease cleavage sites. However, detergents are incompatible with both RP separation and electrospray ionization (ESI). Therefore, to make LC-MS analysis possible, several strategies were implemented in the shotgun proteomics workflow. These techniques rely either on enzymatic digestion in centrifugal filters with subsequent evacuation of the detergent, or employment of MS-compatible surfactants, which can be degraded upon the digestion. In this review we comprehensively address all currently available strategies for the detergent-assisted proteolysis in respect of their relative efficiency when applied to different biological matrices. We critically discuss the current progress and the further perspectives of these technologies in the context of its advances and gaps.
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Affiliation(s)
- Katerina Danko
- Department of Biochemistry, St. Petersburg State University, 199034 St. Petersburg, Russia
| | - Elena Lukasheva
- Department of Biochemistry, St. Petersburg State University, 199034 St. Petersburg, Russia
| | - Vladimir A. Zhukov
- All-Russia Research Institute for Agricultural Microbiology, Podbelsky Chaussee 3, Pushkin, 196608 St. Petersburg, Russia
| | - Viktor Zgoda
- Institute of Biomedical Chemistry, 119121 Moscow, Russia
| | - Andrej Frolov
- K.A. Timiryazev Institute of Plant Physiology RAS, 127276 Moscow, Russia
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Gómez-Guerrero N, González-López N, Zapata-Velásquez JD, Martínez-Ramírez JA, Rivera-Monroy ZJ, García-Castañeda JE. Synthetic Peptides in Doping Control: A Powerful Tool for an Analytical Challenge. ACS OMEGA 2022; 7:38193-38206. [PMID: 36340120 PMCID: PMC9631397 DOI: 10.1021/acsomega.2c05296] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/17/2022] [Accepted: 10/10/2022] [Indexed: 06/16/2023]
Abstract
Peptides are very diverse molecules that can participate in a wide variety of biological processes. In this way, peptides are attractive for doping, since these molecules can activate or trigger biological processes that can improve the sports performance of athletes. Peptide molecules are found in the official World Anti-Doping Agency lists, mainly in sections S2, S4, and S5. In most cases, these molecules have a very short half-life in the body and/or are identical to natural molecules in the body, making it difficult to analyze them as performance-enhancing drugs. This article reviews the role of peptides in doping, with special emphasis on the peptides used as reference materials, the pretreatment of samples in biological matrices, the instrumentation, and the validation of analytical methodologies for the analysis of peptides used in doping. The growing need to characterize and quantify these molecules, especially in complex biological matrices, has generated the need to search for robust strategies that allow for obtaining sensitive and conclusive results. In this sense, strategies such as solid phase peptide synthesis (SPPS), seeking to obtain specific peptides, metabolites, or isotopically labeled analogs, is a key tool for adequate quantification of different peptide molecules in biological matrices. This, together with the use of optimal methodologies for sample pretreatment (e.g., SPE or protein precipitation), and for subsequent analysis by high-resolution techniques (mainly hyphenated LC-HRMS techniques), have become the preferred instrumentation to meet the analytical challenge involved in the analysis of peptides in complex matrices.
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Affiliation(s)
- Néstor
Alejandro Gómez-Guerrero
- Chemistry
Department, Universidad Nacional de Colombia, Bogotá, Carrera 45 No 26-85,
Building 451, 11321 Bogotá, Colombia
- Doping
Control Laboratory, Ministerio del Deporte,
Bogotá, Carrera
68 No 55-65, 111071 Bogotá, Colombia
| | - Nicolás
Mateo González-López
- Pharmacy
Department, Universidad Nacional de Colombia, Bogotá, Carrera 45 No 26-85,
Building 450, 11321 Bogotá, Colombia
| | - Juan Diego Zapata-Velásquez
- Pharmacy
Department, Universidad Nacional de Colombia, Bogotá, Carrera 45 No 26-85,
Building 450, 11321 Bogotá, Colombia
| | - Jorge Ariel Martínez-Ramírez
- Pharmacy
Department, Universidad Nacional de Colombia, Bogotá, Carrera 45 No 26-85,
Building 450, 11321 Bogotá, Colombia
| | - Zuly Jenny Rivera-Monroy
- Chemistry
Department, Universidad Nacional de Colombia, Bogotá, Carrera 45 No 26-85,
Building 451, 11321 Bogotá, Colombia
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Nickerson JL, Doucette AA. Maximizing Cumulative Trypsin Activity with Calcium at Elevated Temperature for Enhanced Bottom-Up Proteome Analysis. BIOLOGY 2022; 11:biology11101444. [PMID: 36290348 PMCID: PMC9598648 DOI: 10.3390/biology11101444] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/24/2022] [Revised: 09/26/2022] [Accepted: 09/28/2022] [Indexed: 11/09/2022]
Abstract
Simple Summary Trypsin is frequently employed to cleave proteins ahead of mass spectrometry characterization. Traditionally, enzyme digestion involves overnight incubation of proteins at 37 °C, which is time consuming though still may yield poor digestion efficiency. While raising the temperature should theoretically accelerate the digestion, it also destabilizes the enzyme and promotes trypsin de-activation. We therefore questioned whether elevated temperature is beneficial for improving tryptic digestion. Here, we quantify protein digestion kinetics at elevated temperatures for calcium-stabilized trypsin and enforce the critical importance of calcium ions to preserve the enzyme. We quantitatively demonstrate that 1 h at 47 °C provides a superior digest when compared to conventional (overnight, 37 °C) processing of the proteome. The practical impact of our enhanced digestion protocol is shown through bottom-up mass spectrometry analysis of a complex proteome mixture. Abstract Bottom-up proteomics relies on efficient trypsin digestion ahead of MS analysis. Prior studies have suggested digestion at elevated temperature to accelerate proteolysis, showing an increase in the number of MS-identified peptides. However, improved sequence coverage may be a consequence of partial digestion, as higher temperatures destabilize and degrade the enzyme, causing enhanced activity to be short-lived. Here, we use a spectroscopic (BAEE) assay to quantify calcium-stabilized trypsin activity over the complete time course of a digestion. At 47 °C, the addition of calcium contributes a 25-fold enhancement in trypsin stability. Higher temperatures show a net decrease in cumulative trypsin activity. Through bottom-up MS analysis of a yeast proteome extract, we demonstrate that a 1 h digestion at 47 °C with 10 mM Ca2+ provides a 29% increase in the total number of peptide identifications. Simultaneously, the quantitative proportion of peptides with 1 or more missed cleavage sites was diminished in the 47 °C digestion, supporting enhanced digestion efficiency with the 1 h protocol. Trypsin specificity also improves, as seen by a drop in the quantitative abundance of semi-tryptic peptides. Our enhanced digestion protocol improves throughput for bottom-up sample preparation and validates the approach as a robust, low-cost alternative to maximized protein digestion efficiency.
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Segl M, Stutz H. Bottom-Up Analysis of Proteins by Peptide Mass Fingerprinting with tCITP-CZE-ESI-TOF MS After Tryptic Digest. Methods Mol Biol 2022; 2531:93-106. [PMID: 35941481 DOI: 10.1007/978-1-0716-2493-7_7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
The identification of proteins in samples of moderate to complex composition is primarily done by bottom-up approaches. Therefore, proteins are enzymatically digested, mostly by trypsin, and the resulting peptides are then separated prior to their transfer to a mass spectrometer. The following protocol portrays a bottom-up method, which was optimized for the application of CZE-ESI-TOF MS. Protein denaturation is achieved by addition of 2,2,2-trifluoroethanol (TFE) and heat treatment. Afterwards, disulfide bonds are reduced with tris-(2-carboxyethyl)phosphine (TCEP) and subsequently alkylated with iodoacetamide (IAA). The tryptic digest is performed in an ammonium bicarbonate buffer at pH 8.0. The digested protein sample is then concentrated in-capillary by transient capillary isotachophoresis (tCITP) with subsequent CZE separation of tryptic peptides in an acidic background electrolyte. Hyphenation to a time-of-flight (TOF) mass spectrometer is carried out by a triple-tube coaxial sheath flow interface, which uses electrospray ionization (ESI). Peptide identification is done by peptide mass fingerprinting (PMF). The protocol is outlined exemplarily for a model protein, i.e., bovine β-lactoglobulin A.
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Affiliation(s)
- Marius Segl
- Department of Biosciences and Medical Biology, University of Salzburg, Salzburg, Austria
- Christian Doppler Laboratory for Innovative Tools for the Characterization of Biosimilars, University of Salzburg, Salzburg, Austria
| | - Hanno Stutz
- Department of Biosciences and Medical Biology, University of Salzburg, Salzburg, Austria.
- Christian Doppler Laboratory for Innovative Tools for the Characterization of Biosimilars, University of Salzburg, Salzburg, Austria.
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Maraming P, Daduang J, Kah JCY. Conjugation with gold nanoparticles improves the stability of the KT2 peptide and maintains its anticancer properties. RSC Adv 2021; 12:319-325. [PMID: 35424498 PMCID: PMC8978663 DOI: 10.1039/d1ra05980g] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2021] [Accepted: 12/01/2021] [Indexed: 12/18/2022] Open
Abstract
One of the major weaknesses of therapeutic peptides is their sensitivity to degradation by proteolytic enzymes in vivo. Gold nanoparticles (GNPs) are a good carrier for therapeutic peptides to improve their stability and cellular uptake in vitro and in vivo. We conjugated the anticancer KT2 peptide as an anticancer peptide model to PEGylated GNPs (GNPs-PEG) and investigated the peptide stability, cellular uptake and ability of the GNPs-KT2-PEG conjugates to induce MDA-MB-231 human breast cancer cell death. We found that 11 nm GNPs protected the conjugated KT2 peptide from trypsin proteolysis, keeping it stable up to 0.128% trypsin, which is higher than the serum trypsin concentration (range 0.0000285 ± 0.0000125%) reported by Lake-Bakaar, G. et al., 1979. GNPs significantly enhanced the cellular uptake of KT2 peptides after conjugation. Free KT2 peptides pretreated with trypsin were not able to kill MDA-MB-231 cells due to proteolysis, while GNPs-KT2-PEG was still able to exert effective cancer cell killing after trypsin treatment at levels comparable to GNPs-KT2-PEG without enzyme pretreatment. The outcome of this study highlights the utility of conjugated anticancer peptides on nanoparticles to improve peptide stability and retain anticancer ability. One of the major weaknesses of therapeutic peptides is their sensitivity to degradation by proteolytic enzymes in vivo.![]()
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Affiliation(s)
- Pornsuda Maraming
- Centre for Research and Development of Medical Diagnostic Laboratories, Faculty of Associated Medical Sciences, Khon Kaen University Khon Kaen 40002 Thailand
| | - Jureerut Daduang
- Centre for Research and Development of Medical Diagnostic Laboratories, Faculty of Associated Medical Sciences, Khon Kaen University Khon Kaen 40002 Thailand
| | - James Chen Yong Kah
- Department of Biomedical Engineering, National University of Singapore 4 Engineering Drive 3, Blk E4, #04-08 Singapore 117583
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Tan A, Xu F, Yokoyama C, Yano S, Konno H. Design, synthesis, and evaluation of the self-assembled antimicrobial peptides based on the ovalbumin-derived peptide TK913. J Pept Sci 2021; 28:e3375. [PMID: 34725889 DOI: 10.1002/psc.3375] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2021] [Revised: 08/09/2021] [Accepted: 09/28/2021] [Indexed: 11/06/2022]
Abstract
The preparation, self-assembly, and antimicrobial activity of peptides based on TK913 is described. TK9Z4 incorporating a Pro-Pro motif exhibited self-assembly but no cytotoxicity. However, peptide TKZ3 (obtained by changing the amino acid sequence of TK9Z4) showed morphological changes at different concentrations, potent antimicrobial activity, low cytotoxicity, and trypsin resistance. Accordingly, TKZ3 is proposed as new AMP derived from ovalbumin-derived peptides.
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Affiliation(s)
- Ao Tan
- Department of Biochemical Engineering, Graduate School of Science and Engineering, Yamagata University, Yonezawa, Japan
| | - Fusheng Xu
- Department of Biochemical Engineering, Graduate School of Science and Engineering, Yamagata University, Yonezawa, Japan
| | - Chikako Yokoyama
- Department of Biochemical Engineering, Graduate School of Science and Engineering, Yamagata University, Yonezawa, Japan
| | - Shigekazu Yano
- Department of Biochemical Engineering, Graduate School of Science and Engineering, Yamagata University, Yonezawa, Japan
| | - Hiroyuki Konno
- Department of Biochemical Engineering, Graduate School of Science and Engineering, Yamagata University, Yonezawa, Japan
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13
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Development of a novel trypsin affinity material using a recombinant buckwheat trypsin inhibitor mutant with enhanced activity. Lebensm Wiss Technol 2021. [DOI: 10.1016/j.lwt.2021.111382] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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Sun B, Smialowski P, Straub T, Imhof A. Investigation and Highly Accurate Prediction of Missed Tryptic Cleavages by Deep Learning. J Proteome Res 2021; 20:3749-3757. [PMID: 34137619 DOI: 10.1021/acs.jproteome.1c00346] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Trypsin is one of the most important and widely used proteolytic enzymes in mass spectrometry (MS)-based proteomic research. It exclusively cleaves peptide bonds at the C-terminus of lysine and arginine. However, the cleavage is also affected by several factors, including specific surrounding amino acids, resulting in frequent incomplete proteolysis and subsequent issues in peptide identification and quantification. The accurate annotations on missed cleavages are crucial to database searching in MS analysis. Here, we present deep-learning predicting missed cleavages (dpMC), a novel algorithm for the prediction of missed trypsin cleavage sites. This algorithm provides a very high accuracy for predicting missed cleavages with area under the curves (AUCs) of cross-validation and holdout testing above 0.99, along with the mean F1 score and the Matthews correlation coefficient (MCC) of 0.9677 and 0.9349, respectively. We tested our algorithm on data sets from different species and different experimental conditions, and its performance outperforms other currently available prediction methods. In addition, the method also provides a better insight into the detailed rules of trypsin cleavages coupled with propensity and motif analysis. Moreover, our method can be integrated into database searching in the MS analysis to identify and quantify mass spectra effectively and efficiently.
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Affiliation(s)
- Bo Sun
- Biomedical Center, Protein Analysis Unit, Faculty of Medicine, Ludwig-Maximilians-Universität München, Großhaderner Strasse 9, 82152 Planegg-Martinsried, Germany
| | - Pawel Smialowski
- Institute of Stem Cell Research, Helmholtz Center Munich, German Research Center for Environmental Health, 85764 Munich, Germany.,Biomedical Center, Computational Biology Unit, Faculty of Medicine, Ludwig-Maximilians-Universität München, Großhaderner Strasse 9, 82152 Planegg-Martinsried, Germany
| | - Tobias Straub
- Biomedical Center, Computational Biology Unit, Faculty of Medicine, Ludwig-Maximilians-Universität München, Großhaderner Strasse 9, 82152 Planegg-Martinsried, Germany
| | - Axel Imhof
- Biomedical Center, Protein Analysis Unit, Faculty of Medicine, Ludwig-Maximilians-Universität München, Großhaderner Strasse 9, 82152 Planegg-Martinsried, Germany
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15
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Matthies I, Abrahams JL, Jensen P, Oliveira T, Kolarich D, Larsen MR. N-Glycosylation in isolated rat nerve terminals. Mol Omics 2021; 17:517-532. [PMID: 34106099 DOI: 10.1039/d0mo00044b] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
N-linked glycosylation is a ubiquitous protein modification that is capable of modulating protein structure, function and interactions. Many proteins in the brain associated with the synapse and important for synaptic transmission are highly glycosylated and their glycosylation could be important for learning and memory related molecular processes and synaptic plasticity. In the present study, we extend the knowledge of the synaptic glycome and glycoproteome by performing glycan- and intact glycopeptide-focused analyses of isolated rat nerve terminals (synaptosomes) by LC-MS/MS. Overall, glycomics identified a total of 41 N-glycans in isolated synaptosomes. Sialylated N-glycans represented only 7% of the total abundance of the rat synaptosome N-glycome with oligomannose, neutral hybrid and complex type N-glycans being the most abundant structures. Using detergent extraction of the active zone proteins from the synaptosomes revealed a change in the active zone glycan abundance in comparison with the rest of the synaptosome glycan content. Characterization of intact sialylated N-linked glycopeptides enriched by titanium dioxide chromatography revealed more than 85% selectivity of sialylated species and the presence of NeuGc on active zone proteins. In addition, both disialic and trisialic acid modified glycans were present on synaptic glycoproteins, although oxonium ion profiling revealed that trisialic units were only present on glycoproteins in the detergent soluble fraction. However, correct identification of intact sialylated N-linked glycopeptides using the Byonic program failed, most likely due to the lack of peptide backbone fragmentation during tandem mass spectrometry.
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Affiliation(s)
- Inga Matthies
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, Denmark
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16
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Forensic proteomics. Forensic Sci Int Genet 2021; 54:102529. [PMID: 34139528 DOI: 10.1016/j.fsigen.2021.102529] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2020] [Revised: 05/06/2021] [Accepted: 05/07/2021] [Indexed: 12/19/2022]
Abstract
Protein is a major component of all biological evidence, often the matrix that embeds other biomolecules such as polynucleotides, lipids, carbohydrates, and small molecules. The proteins in a sample reflect the transcriptional and translational program of the originating cell types. Because of this, proteins can be used to identify body fluids and tissues, as well as convey genetic information in the form of single amino acid polymorphisms, the result of non-synonymous SNPs. This review explores the application and potential of forensic proteomics. The historical role that protein analysis played in the development of forensic science is examined. This review details how innovations in proteomic mass spectrometry have addressed many of the historical limitations of forensic protein science, and how the application of forensic proteomics differs from proteomics in the life sciences. Two more developed applications of forensic proteomics are examined in detail: body fluid and tissue identification, and proteomic genotyping. The review then highlights developing areas of proteomics that have the potential to impact forensic science in the near future: fingermark analysis, species identification, peptide toxicology, proteomic sex estimation, and estimation of post-mortem intervals. Finally, the review highlights some of the newer innovations in proteomics that may drive further development of the field. In addition to potential impact, this review also attempts to evaluate the stage of each application in the development, validation and implementation process. This review is targeted at investigators who are interested in learning about proteomics in a forensic context and expanding the amount of information they can extract from biological evidence.
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17
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Dadouch M, Ladner Y, Bich C, Montels J, Morel J, Perrin C. Fast in-line bottom-up analysis of monoclonal antibodies: Toward an electrophoretic fingerprinting approach. Electrophoresis 2021; 42:1229-1237. [PMID: 33650106 DOI: 10.1002/elps.202000375] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2020] [Revised: 02/22/2021] [Accepted: 02/24/2021] [Indexed: 01/08/2023]
Abstract
For their characterization and quality control, monoclonal antibodies are frequently analyzed at the bottom-up level to generate specific fingerprints that can be used to tackle post-translational modifications or ensure production consistency between lots. To circumvent time-consuming and labor-intensive off-line sample preparation steps, the implementation of integrated methodologies from sample preparation to separation and detection is highly valuable. In this perspective, capillary zone electrophoresis appears as a choice technique since the capillary can subsequently be used as a vessel for sample preparation and electrophoretic discrimination/detection of the reaction products. Here, a fast in-line methodology for the routine quality control of mAbs at the bottom-up level is reported. Simultaneous denaturation and reduction (pretreatment step) were conducted with RapiGest® surfactant and dithiothreitol before in-line tryptic digestion. Reactant mixing was realized by transverse diffusion of laminar flow profile under controlled temperature. In-line digestion was carried out with a resistant trypsin to autolysis. The main parameters affecting the digestion efficiency (trypsin concentration and incubation conditions) were optimized to generate mAb electrophoretic profiles free from trypsin interferences. An acidic MS-compatible BGE was used to obtain high resolution separation of released peptides and in-line surfactant cleavage. The whole methodology was performed in less than two hours with good repeatability of migration times (RSD = 0.91%, n = 5) and corrected peak areas (RSD = 9.6%, n = 5). CE-fingerprints were successfully established for different mAbs and an antibody-drug conjugate.
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Affiliation(s)
- Meriem Dadouch
- UMR 5247-CNRS-UM-ENSCM, Institut des Biomolécules Max Mousseron (IBMM), Université de Montpellier, Montpellier, France
| | - Yoann Ladner
- UMR 5247-CNRS-UM-ENSCM, Institut des Biomolécules Max Mousseron (IBMM), Université de Montpellier, Montpellier, France
| | - Claudia Bich
- UMR 5247-CNRS-UM-ENSCM, Institut des Biomolécules Max Mousseron (IBMM), Université de Montpellier, Montpellier, France
| | - Jérôme Montels
- UMR 5247-CNRS-UM-ENSCM, Institut des Biomolécules Max Mousseron (IBMM), Université de Montpellier, Montpellier, France
| | - Jacques Morel
- Département de Rhumatologie, Université de Montpellier, Hôpital Lapeyronie, Montpellier Cedex 5, 34295, France
| | - Catherine Perrin
- UMR 5247-CNRS-UM-ENSCM, Institut des Biomolécules Max Mousseron (IBMM), Université de Montpellier, Montpellier, France
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18
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Evaluation of biological activities, structural and conformational properties of bovine beta- and alpha-trypsin isoforms in aqueous-organic media. Int J Biol Macromol 2021; 176:291-303. [PMID: 33592263 DOI: 10.1016/j.ijbiomac.2021.02.079] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2020] [Revised: 02/01/2021] [Accepted: 02/11/2021] [Indexed: 01/01/2023]
Abstract
The study of the biological activity of trypsin isoforms in aqueous-organic media is of great interest to various fields of knowledge and biochemistry applications. Thus enzymatic, structural, and energetic properties of bovine β- and α-trypsin isoforms were compared in aqueous-organic media using 30 mg of each isoform. The results showed that the changes induced on the structure and activity of the same trypsin isoform occur at different concentrations. Better results for activity (ionic strength of 0.11 mol·L-1, at 37 °C and pH 8.0) were found in 0-40% of ethanolic media in which the activity for β-trypsin was about 60% higher than ɑ-trypsin. The ethanolic system does not cause significant changes in the level of secondary structure but the β-trypsin isoform undergoes a major rearrangement. The use of until 60% (v/v) ethanol showed that β-trypsin presents a denaturation process 17% more cooperative. The organic solvent causes redistribution in the supramolecular arrangement of both isoforms: all concentrations used induced the β-trypsin molecules to rearrange into agglomerates. The ɑ-trypsin rearranges into agglomerates up to 60% (v/v) of ethanol and aggregates at 80% (v/v) of ethanol. Both isoforms keep the enzymatic activity up to 60% (v/v) of ethanol.
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Takemori A, Ishizaki J, Nakashima K, Shibata T, Kato H, Kodera Y, Suzuki T, Hasegawa H, Takemori N. BAC-DROP: Rapid Digestion of Proteome Fractionated via Dissolvable Polyacrylamide Gel Electrophoresis and Its Application to Bottom-Up Proteomics Workflow. J Proteome Res 2020; 20:1535-1543. [PMID: 33356312 DOI: 10.1021/acs.jproteome.0c00749] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The GeLC-MS workflow, which combines low-cost, easy-to-use sodium dodecyl sulfate (SDS)-polyacrylamide gel electrophoresis (SDS-PAGE) with liquid chromatography-mass spectrometry (LC-MS), is very popular in current bottom-up proteomics. However, GeLC-MS requires that PAGE-separated proteins undergo overnight enzymatic digestion in a gel, resulting in more than 20 h of sample preparation for LC-MS. In this study, we overcame the limitations of GeLC-MS by developing a rapid digestion workflow for PAGE separation of proteins using N,N'-bis(acryloyl)cystamine (BAC) cross-linked gels that can be solubilized by reductive treatment. Making use of an established workflow called BAC-DROP (BAC-gel dissolution to digest PAGE-resolved objective proteins), crude proteome samples were fractionated based on molecular weight by BAC cross-linked PAGE. After fractionation, the gel fragments were reductively dissolved in under 5 min, and in-solution trypsin digestion of the protein released from the gel was completed in less than 1 h at 70 °C, equivalent to a 90-95% reduction in time compared to conventional in-gel trypsin digestion. The introduction of the BAC-DROP workflow to the MS assays for inflammatory biomarker CRP and viral marker HBsAg allowed for serum sample preparation to be completed in as little as 5 h, demonstrating successful marker quantification from a 0.5 μL sample of human serum.
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Affiliation(s)
- Ayako Takemori
- Division of Analytical Bio-Medicine, Advanced Research Support Center, Ehime University, Toon 790-8577, Ehime, Japan
| | - Jun Ishizaki
- Department of Hematology, Clinical Immunology and Infectious Diseases, Graduate School of Medicine, Ehime University, Toon 790-8577, Ehime, Japan
| | - Kenji Nakashima
- Department of Virology and Parasitology, Hamamatsu University School of Medicine, Hamamatsu 431-3192, Shizuoka, Japan
| | | | - Hidemasa Kato
- Division of Functional Histology, Department of Functional Biomedicine, Graduate School of Medicine, Ehime University, Toon 790-8577, Ehime, Japan
| | - Yoshio Kodera
- Center for Disease Proteomics, Kitasato University School of Science, Sagamihara 252-0373, Kanagawa, Japan
| | - Tetsuro Suzuki
- Department of Virology and Parasitology, Hamamatsu University School of Medicine, Hamamatsu 431-3192, Shizuoka, Japan
| | - Hitoshi Hasegawa
- Department of Hematology, Clinical Immunology and Infectious Diseases, Graduate School of Medicine, Ehime University, Toon 790-8577, Ehime, Japan
| | - Nobuaki Takemori
- Division of Analytical Bio-Medicine, Advanced Research Support Center, Ehime University, Toon 790-8577, Ehime, Japan
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20
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Bottom-up sample preparation for the LC-MS/MS quantification of anti-cancer monoclonal antibodies in bio matrices. Bioanalysis 2020; 12:1405-1425. [PMID: 32975434 DOI: 10.4155/bio-2020-0204] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
Therapeutic monoclonal antibodies (mAbs) are rapidly taking over the treatment of many malignancies, and an astonishing number of mAbs is in development. This causes a high demand for quantification of mAbs in biomatrices both for measuring therapeutic mAb concentrations and to support pharmacokinetics and pharmacodynamics studies. Conventionally, ligand-binding assays are used for these purposes, but LC-MS is gaining popularity. Although intact (top-down) and subunit (middle-down) mAb quantification is reported, signature peptide (bottom-up) quantification is currently most advantageous. This review provides an overview of the reported bottom-up mAb quantification methods in biomatrices as well as general recommendations regarding signature peptide and internal standard selection, reagent use and optimization of digestion in bottom-up quantification methods.
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21
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Nonspecific cleavages arising from reconstitution of trypsin under mildly acidic conditions. PLoS One 2020; 15:e0236740. [PMID: 32722706 PMCID: PMC7386593 DOI: 10.1371/journal.pone.0236740] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2020] [Accepted: 07/13/2020] [Indexed: 11/19/2022] Open
Abstract
Tryptic digestion of proteins followed by liquid chromatography with tandem mass spectrometry analysis is an extensively used approach in proteomics research and biopharmaceutical product characterization, owing to the high level of cleavage fidelity produced with this technique. However, nonspecific trypsin cleavages have been frequently reported and shown to be related to a number of digestion conditions and predigestion sample treatments. In this work, we reveal that, for a number of commercial trypsins, reconstitution and storage conditions can have a significant impact on the occurrence of trypsin nonspecific cleavages. We analyzed the tryptic digestion of a variety of biotherapeutics, using trypsins reconstituted under different conditions. The results indicate that, for many commercial trypsins, commonly recommended reconstitution/storage conditions (mildly acidic, e.g., 50 mM acetic acid, 1 mM HCl) can actually promote nonspecific trypsin activities, which are time dependent and can be as high as 20% in total relative abundance. In contrast, using water for reconstitution and storage can effectively limit nonspecific cleavages to 1%. Interestingly, the performances of different commercial trypsins were found to be quite distinct in their levels of nonspecific cleavages and responses to the two reconstitution conditions. Our findings demonstrate the importance of choosing the appropriate trypsin for tryptic digestion and the necessity of assessing the impact of trypsin reconstitution and storage on nonspecific cleavages. We advocate for manufacturers of commercial trypsins to reevaluate manufacturing processes and reconstitution/storage conditions to provide good cleavage specificity.
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22
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Aspartic Acid Isomerization Characterized by High Definition Mass Spectrometry Significantly Alters the Bioactivity of a Novel Toxin from Poecilotheria. Toxins (Basel) 2020; 12:toxins12040207. [PMID: 32218140 PMCID: PMC7232244 DOI: 10.3390/toxins12040207] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2020] [Revised: 03/20/2020] [Accepted: 03/23/2020] [Indexed: 11/25/2022] Open
Abstract
Research in toxinology has created a pharmacological paradox. With an estimated 220,000 venomous animals worldwide, the study of peptidyl toxins provides a vast number of effector molecules. However, due to the complexity of the protein-protein interactions, there are fewer than ten venom-derived molecules on the market. Structural characterization and identification of post-translational modifications are essential to develop biological lead structures into pharmaceuticals. Utilizing advancements in mass spectrometry, we have created a high definition approach that fuses conventional high-resolution MS-MS with ion mobility spectrometry (HDMSE) to elucidate these primary structure characteristics. We investigated venom from ten species of “tiger” spider (Genus: Poecilotheria) and discovered they contain isobaric conformers originating from non-enzymatic Asp isomerization. One conformer pair conserved in five of ten species examined, denominated PcaTX-1a and PcaTX-1b, was found to be a 36-residue peptide with a cysteine knot, an amidated C-terminus, and isoAsp33Asp substitution. Although the isomerization of Asp has been implicated in many pathologies, this is the first characterization of Asp isomerization in a toxin and demonstrates the isomerized product’s diminished physiological effects. This study establishes the value of a HDMSE approach to toxin screening and characterization.
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23
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Larsen DN, Mikkelsen CE, Kierkegaard M, Bereta GP, Nowakowska Z, Kaczmarek JZ, Potempa J, Højrup P. Citrullinome of Porphyromonas gingivalis Outer Membrane Vesicles: Confident Identification of Citrullinated Peptides. Mol Cell Proteomics 2020; 19:167-180. [PMID: 31754044 PMCID: PMC6944236 DOI: 10.1074/mcp.ra119.001700] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2019] [Revised: 11/12/2019] [Indexed: 12/20/2022] Open
Abstract
Porphyromonas gingivalis is a key pathogen in chronic periodontitis and has recently been mechanistically linked to the development of rheumatoid arthritis via the activity of peptidyl arginine deiminase generating citrullinated epitopes in the periodontium. In this project the outer membrane vesicles (OMV) from P. gingivalis W83 wild-type (WT), a W83 knock-out mutant of peptidyl arginine deiminase (ΔPPAD), and a mutant strain expressing PPAD with the active site cysteine mutated to alanine (C351A), have been analyzed using a two-dimensional HFBA-based separation system combined with LC-MS. For optimal and positive identification and validation of citrullinated peptides and proteins, high resolution mass spectrometers and strict MS search criteria were utilized. This may have compromised the total number of identified citrullinations but increased the confidence of the validation. A new two-dimensional separation system proved to increase the strength of validation, and along with the use of an in-house build program, Citrullia, we establish a fast and easy semi-automatic (manual) validation of citrullinated peptides. For the WT OMV we identified 78 citrullinated proteins having a total of 161 citrullination sites. Notably, in keeping with the mechanism of OMV formation, the majority (51 out of 78) of citrullinated proteins were predicted to be exported via the inner membrane and to reside in the periplasm or being translocated to the bacterial surface. Citrullinated surface proteins may contribute to the pathogenesis of rheumatoid arthritis. For the C351A-OMV a single citrullination site was found and no citrullinations were identified for the ΔPPAD-OMV, thus validating the unbiased character of our method of citrullinated peptide identification.
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Affiliation(s)
| | | | | | - Grzegorz P Bereta
- Department of Microbiology, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Krakow, Poland
| | - Zuzanna Nowakowska
- Department of Microbiology, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Krakow, Poland; Malopolska Center of Biotechnology, Jagiellonian University, Krakow, Poland
| | - Jakub Z Kaczmarek
- Research and Development Department, Ovodan Biotech A/S, 5000 Odense, Denmark
| | - Jan Potempa
- Department of Microbiology, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Krakow, Poland; Department of Oral Immunology and Infectious Diseases, University of Louisville School of Dentistry, 501 S. Preston St., Louisville, Kentucky
| | - Peter Højrup
- University of Southern Denmark, Campusvej 55, Odense M, Denmark.
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