1
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Ying Y, Li H. Native top-down mass spectrometry for monitoring the rapid chymotrypsin catalyzed hydrolysis reaction. Anal Chim Acta 2024; 1285:341971. [PMID: 38057065 DOI: 10.1016/j.aca.2023.341971] [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: 06/12/2023] [Revised: 10/13/2023] [Accepted: 10/26/2023] [Indexed: 12/08/2023]
Abstract
Enzymes play crucial roles in life sciences, pharmaceuticals and industries as biological catalysts that speed up biochemical reactions in living organisms. New catalytic reactions are continuously developed by enzymatic engineering to meet industrial needs, which thereby drives the development of analytical approaches for real-time reaction monitoring to reveal catalytic processes. Here, taking the hydrolase- chymotrypsin as a model system, we proposed a convenient method for monitoring catalytic processes through native top-down mass spectrometry (native TDMS). The chymotrypsin sample heterogeneity was first explored. By altering sample introduction modes and pHs, covalent and noncovalent enzymatic complexes, substrates and products can be monitored during the catalysis and further confirmed by tandem MS. Our results demonstrated that native TDMS based catalysis monitoring has distinctive strength on real-time inspection and continuous observation, making it a promising tool for characterizing more biocatalysts.
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Affiliation(s)
- Yujia Ying
- School of Pharmaceutical Sciences, Sun Yat-Sen University, Guangzhou, 510006, China.
| | - Huilin Li
- School of Pharmaceutical Sciences, Sun Yat-Sen University, Guangzhou, 510006, China; Guangdong Key Laboratory of Chiral Molecule and Drug Discovery, School of Pharmaceutical Sciences, Sun Yat-Sen University, Guangzhou, 510006, China.
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2
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Edwards M, Freitas DP, Hirtzel EA, White N, Wang H, Davidson LA, Chapkin RS, Sun Y, Yan X. Interfacial Electromigration for Analysis of Biofluid Lipids in Small Volumes. Anal Chem 2023; 95:18557-18563. [PMID: 38050376 PMCID: PMC10862378 DOI: 10.1021/acs.analchem.3c04309] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2023] [Revised: 11/19/2023] [Accepted: 11/21/2023] [Indexed: 12/06/2023]
Abstract
Lipids are important biomarkers within the field of disease diagnostics and can serve as indicators of disease progression and predictors of treatment effectiveness. Although lipids can provide important insight into how diseases initiate and progress, mass spectrometric methods for lipid characterization and profiling are limited due to lipid structural diversity, particularly the presence of various lipid isomers. Moreover, the difficulty of handling small-volume samples exacerbates the intricacies of biological analyses. In this work, we have developed a strategy that electromigrates a thin film of a small-volume biological sample directly to the air-liquid interface formed at the tip of a theta capillary. Importantly, we seamlessly integrated in situ biological lipid extraction with accelerated chemical derivatization, enabled by the air-liquid interface, and conducted isomeric structural characterization within a unified platform utilizing theta capillary nanoelectrospray ionization mass spectrometry, all tailored for small-volume sample analysis. We applied this unified platform to the analysis of lipids from small-volume human plasma and Alzheimer's disease mouse serum samples. Accelerated electro-epoxidation of unsaturated lipids at the interface allowed us to characterize lipid double-bond positional isomers. The unique application of electromigration of a thin film to the air-liquid interface in combination with accelerated interfacial reactions holds great potential in small-volume sample analysis for disease diagnosis and prevention.
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Affiliation(s)
- Madison
E. Edwards
- Department
of Chemistry, Texas A&M University, 580 Ross Street, College Station, Texas 77843, United States
| | - Dallas P. Freitas
- Department
of Chemistry, Texas A&M University, 580 Ross Street, College Station, Texas 77843, United States
| | - Erin A. Hirtzel
- Department
of Chemistry, Texas A&M University, 580 Ross Street, College Station, Texas 77843, United States
| | - Nicholas White
- Department
of Chemistry, Texas A&M University, 580 Ross Street, College Station, Texas 77843, United States
| | - Hongying Wang
- Department
of Nutrition, Texas A&M University, 373 Olsen Blvd, College Station, Texas 77845, United States
| | - Laurie A. Davidson
- Department
of Nutrition, Texas A&M University, 373 Olsen Blvd, College Station, Texas 77845, United States
| | - Robert S. Chapkin
- Department
of Nutrition, Texas A&M University, 373 Olsen Blvd, College Station, Texas 77845, United States
| | - Yuxiang Sun
- Department
of Nutrition, Texas A&M University, 373 Olsen Blvd, College Station, Texas 77845, United States
| | - Xin Yan
- Department
of Chemistry, Texas A&M University, 580 Ross Street, College Station, Texas 77843, United States
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3
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Song Z, Liang C, Gong K, Zhao S, Yuan X, Zhang X, Xie J. Harnessing the High Interfacial Electric Fields on Water Microdroplets to Accelerate Menshutkin Reactions. J Am Chem Soc 2023; 145:26003-26008. [PMID: 38011046 DOI: 10.1021/jacs.3c11650] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2023]
Abstract
Even though it is still an emerging field, the application of a high external electric field (EEF) as a green and efficient catalyst in synthetic chemistry has recently received significant attention for the ability to deliver remarkable control of reaction selectivity and acceleration of reaction rates. Here, we extend the application of the EEF to Menshutkin reactions by taking advantage of the spontaneous high electric field at the air-water interfaces of sprayed water microdroplets. Experimentally, a series of Menshutkin reactions were accelerated by 7 orders of magnitude. Theoretically, both density functional theory calculations and ab initio molecular dynamics simulations predict that the reaction barrier decreases significantly in the presence of oriented external electric fields, thereby supporting the notion that the electric fields in the water droplets are responsible for the catalysis. In addition, the ordered solvent and reactant molecules oriented by the electric field alleviate the steric effect of solvents and increase the successful collision rates, thus facilitating faster nucleophilic attack. The success of Menshutkin reactions in this study showcases the great potential of microdroplet chemistry for green synthesis.
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Affiliation(s)
- Zhexuan Song
- Key Laboratory of Cluster Science of Ministry of Education, Beijing Key Laboratory of Photoelectronic/Electrophotonic Conversion Materials, School of Chemistry and Chemical Engineering, Beijing Institute of Technology, Beijing 100081, China
| | - Chiyu Liang
- College of Chemistry, Key Laboratory of Advanced Energy Materials Chemistry (Ministry of Education), Renewable Energy Conversion and Storage Centre, Tianjin Key Laboratory of Biosensing and Molecular Recognition, Frontiers Science Centre for New Organic Matter, Nankai University, Tianjin 300071, China
- Beijing National Laboratory for Molecular Sciences, Beijing 100190, China
| | - Ke Gong
- Key Laboratory of Cluster Science of Ministry of Education, Beijing Key Laboratory of Photoelectronic/Electrophotonic Conversion Materials, School of Chemistry and Chemical Engineering, Beijing Institute of Technology, Beijing 100081, China
| | - Supin Zhao
- Key Laboratory of Cluster Science of Ministry of Education, Beijing Key Laboratory of Photoelectronic/Electrophotonic Conversion Materials, School of Chemistry and Chemical Engineering, Beijing Institute of Technology, Beijing 100081, China
| | - Xu Yuan
- College of Chemistry, Key Laboratory of Advanced Energy Materials Chemistry (Ministry of Education), Renewable Energy Conversion and Storage Centre, Tianjin Key Laboratory of Biosensing and Molecular Recognition, Frontiers Science Centre for New Organic Matter, Nankai University, Tianjin 300071, China
- Beijing National Laboratory for Molecular Sciences, Beijing 100190, China
| | - Xinxing Zhang
- College of Chemistry, Key Laboratory of Advanced Energy Materials Chemistry (Ministry of Education), Renewable Energy Conversion and Storage Centre, Tianjin Key Laboratory of Biosensing and Molecular Recognition, Frontiers Science Centre for New Organic Matter, Nankai University, Tianjin 300071, China
- Beijing National Laboratory for Molecular Sciences, Beijing 100190, China
| | - Jing Xie
- Key Laboratory of Cluster Science of Ministry of Education, Beijing Key Laboratory of Photoelectronic/Electrophotonic Conversion Materials, School of Chemistry and Chemical Engineering, Beijing Institute of Technology, Beijing 100081, China
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4
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Chen CJ, Williams ER. Variable Mixing with Theta Emitter Mass Spectrometry: Changing Solution Flow Rates with Emitter Position. Anal Chem 2023; 95:14777-14786. [PMID: 37729435 DOI: 10.1021/acs.analchem.3c02980] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/22/2023]
Abstract
Two solutions can be rapidly mixed using theta glass emitters, with products measured using electrospray ionization mass spectrometry. The relative flow rates of the two emitter channels can be measured using different calibration compounds in each channel, or the flow rates are often assumed to be the same. The relative flow rates of each channel can be essentially the same when the emitters are positioned directly in front of the capillary entrance of a mass spectrometer, but the relative flow rates can be varied by up to 3 orders of magnitude by moving the position of the emitter tip ±1 cm in a direction that is perpendicular to the inner divider. Results of the emitter position on the different concentrations of reagents in the initially formed electrospray droplets are demonstrated through protein denaturation using a supercharging reagent as well as two different bimolecular reactions. The average charge state of myoglobin changed from +7.8 to +13.8 when 2.5% sulfolane was mixed with a 200 mM ammonium acetate solution containing the protein when the position of the emitter was scanned in front of the mass spectrometer inlet. The conversion ratio of a bimolecular reaction was changed from 0.98 to 0.04 with varying emitter positions. These results show that the relative flow rates must be carefully monitored because the droplet composition depends strongly on the position of the theta glass emitters. This method can be used to measure the dependence of reaction kinetics on different solution concentrations by using a single emitter and only two solutions.
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Affiliation(s)
- Casey J Chen
- Department of Chemistry, University of California, Berkeley, California 94720, United States
| | - Evan R Williams
- Department of Chemistry, University of California, Berkeley, California 94720, United States
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5
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Sharif D, Rahman M, Mahmud S, Sultana MN, Attanayake K, DeBastiani A, Foroushani SH, Li P, Valentine SJ. In-droplet hydrogen-deuterium exchange to examine protein/peptide solution conformer heterogeneity. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2023; 37:e9593. [PMID: 37430450 DOI: 10.1002/rcm.9593] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/07/2023] [Revised: 04/25/2023] [Accepted: 05/22/2023] [Indexed: 07/12/2023]
Abstract
RATIONALE Many different structure analysis techniques are not capable of probing the heterogeneity of solution conformations. Here, we examine the ability of in-droplet hydrogen-deuterium exchange (HDX) to directly probe solution conformer heterogeneity of a protein with mass spectrometry (MS) detection. METHODS Two vibrating capillary vibrating sharp-edge spray ionization (cVSSI) devices have been arranged such that they generate microdroplet plumes of the analyte and D2 O reagent, which coalesce to form reaction droplets where HDX takes place in the solution environment. The native HDX-MS setup has been first explored for two model peptides that have distinct structural compositions in solution. The effectiveness of the multidevice cVSSI-HDX in illustrating structural details has been further exploited to investigate coexisting solution-phase conformations of the protein ubiquitin. RESULTS In-droplet HDX reveals decreased backbone exchange for a model peptide that has a greater helix-forming propensity. Differences in intrinsic rates of the alanine and serine residues may account for much of the observed protection. The data allow the first estimates of backbone exchange rates for peptides undergoing in-droplet HDX. That said, the approach may hold greater potential for investigating the tertiary structure and structural transitions of proteins. For ubiquitin protein, HDX reactivity differences suggest that multiple conformers are present in native solutions. The addition of methanol to buffered aqueous solutions of ubiquitin results in increased populations of solution conformers of higher reactivity. Data analysis suggests that partially folded conformers such as the A-state of ubiquitin increase with methanol content; the native state may be preserved to a limited degree even under stronger denaturation conditions. CONCLUSION The deuterium uptake after in-droplet HDX has been observed to correspond to some degree with peptide backbone hydrogen protection based on differences in intrinsic rates of exchange. The presence of coexisting protein solution structures under native and denaturing solution conditions has been distinguished by the isotopic distributions of deuterated ubiquitin ions.
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Affiliation(s)
- Daud Sharif
- C. Eugene Bennett Department of Chemistry, West Virginia University, Morgantown, West Virginia, USA
| | - Mohammad Rahman
- C. Eugene Bennett Department of Chemistry, West Virginia University, Morgantown, West Virginia, USA
| | - Sultan Mahmud
- C. Eugene Bennett Department of Chemistry, West Virginia University, Morgantown, West Virginia, USA
| | - Mst Nigar Sultana
- C. Eugene Bennett Department of Chemistry, West Virginia University, Morgantown, West Virginia, USA
| | - Kushani Attanayake
- C. Eugene Bennett Department of Chemistry, West Virginia University, Morgantown, West Virginia, USA
| | - Anthony DeBastiani
- C. Eugene Bennett Department of Chemistry, West Virginia University, Morgantown, West Virginia, USA
| | - Samira Hajian Foroushani
- C. Eugene Bennett Department of Chemistry, West Virginia University, Morgantown, West Virginia, USA
| | - Peng Li
- C. Eugene Bennett Department of Chemistry, West Virginia University, Morgantown, West Virginia, USA
| | - Stephen J Valentine
- C. Eugene Bennett Department of Chemistry, West Virginia University, Morgantown, West Virginia, USA
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6
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Hatvany JB, Gallagher ES. Hydrogen/deuterium exchange for the analysis of carbohydrates. Carbohydr Res 2023; 530:108859. [PMID: 37290371 DOI: 10.1016/j.carres.2023.108859] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2023] [Revised: 05/26/2023] [Accepted: 05/30/2023] [Indexed: 06/10/2023]
Abstract
Carbohydrates and glycans are integral to many biological processes, including cell-cell recognition and energy storage. However, carbohydrates are often difficult to analyze due to the high degree of isomerism present. One method being developed to distinguish these isomeric species is hydrogen/deuterium exchange-mass spectrometry (HDX-MS). In HDX-MS, carbohydrates are exposed to a deuterated reagent and the functional groups with labile hydrogen atoms, including hydroxyls and amides, exchange with the 1 amu heavier isotope, deuterium. These labels can then be detected by MS, which monitors the mass increase with the addition of D-labels. The observed rate of exchange is dependent on the exchanging functional group, the accessibility of the exchanging functional group, and the presence of hydrogen bonds. Herein, we discuss how HDX has been applied in the solution-phase, gas-phase, and during MS ionization to label carbohydrates and glycans. Additionally, we compare differences in the conformations that are labeled, the labeling timeframes, and applications of each of these methods. Finally, we comment on future opportunities for development and use of HDX-MS to analyze glycans and glycoconjugates.
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Affiliation(s)
- Jacob B Hatvany
- Department of Chemistry and Biochemistry, Baylor University, One Bear Place #97348, Waco, TX, 76798, USA
| | - Elyssia S Gallagher
- Department of Chemistry and Biochemistry, Baylor University, One Bear Place #97348, Waco, TX, 76798, USA.
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7
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Chen CJ, Williams ER. The role of analyte concentration in accelerated reaction rates in evaporating droplets. Chem Sci 2023; 14:4704-4713. [PMID: 37181782 PMCID: PMC10171075 DOI: 10.1039/d3sc00259d] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2023] [Accepted: 04/04/2023] [Indexed: 05/16/2023] Open
Abstract
Accelerated reactions in microdroplets have been reported for a wide range of reactions with some microdroplet reactions occurring over a million times faster than the same reaction in bulk solution. Unique chemistry at the air-water interface has been implicated as a primary factor for accelerated reaction rates, but the role of analyte concentration in evaporating droplets has not been as well studied. Here, theta-glass electrospray emitters and mass spectrometry are used to rapidly mix two solutions on the low to sub-microsecond time scale and produce aqueous nanodrops with different sizes and lifetimes. We demonstrate that for a simple bimolecular reaction where surface chemistry does not appear to play a role, reaction rate acceleration factors are between 102 and 107 for different initial solution concentrations, and these values do not depend on nanodrop size. A rate acceleration factor of 107 is among the highest reported and can be attributed to concentration of analyte molecules, initially far apart in dilute solution, but brought into close proximity in the nanodrop through evaporation of solvent from the nanodrops prior to ion formation. These data indicate that analyte concentration phenomenon is a significant factor in reaction acceleration where droplet volume throughout the experiment is not carefully controlled.
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Affiliation(s)
- Casey J Chen
- Department of Chemistry, University of California Berkeley CA 94720 USA
| | - Evan R Williams
- Department of Chemistry, University of California Berkeley CA 94720 USA
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8
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Aerts JT, Andrén PE, Jansson ET. Electrochemically Etched Tapered-Tip Stainless-Steel Electrospray-Ionization Emitters for Capillary Electrophoresis-Mass Spectrometry. J Proteome Res 2023; 22:1377-1380. [PMID: 36866861 PMCID: PMC10088039 DOI: 10.1021/acs.jproteome.3c00076] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/04/2023]
Abstract
We have used household consumables to facilitate electrochemical etching of stainless-steel hypodermic tubing to produce tapered-tip emitters suitable for electrospray ionization for use in mass spectrometry. The process involves the use of 1% oxalic acid and a 5 W USB power adapter, commonly known as a phone charger. Further, our method avoids the otherwise commonly used strong acids that entail chemical hazards: concentrated HNO3 for etching stainless steel, or concentrated HF for etching fused silica. Hence, we here provide a convenient and self-inhibiting procedure with minimal chemical hazards to manufacture tapered-tip stainless-steel emitters. We show its performance in metabolomic analysis with CE-MS of a tissue homogenate where the metabolites acetylcarnitine, arginine, carnitine, creatine, homocarnosine, and valerylcarnitine were identified, all with basepeak separated electropherograms, within <6 min of separation. The mass spectrometry data are freely available through the MetaboLight public data repository via access number MTBLS7230.
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Affiliation(s)
- Jordan T Aerts
- Department of Pharmaceutical Biosciences, Uppsala University, SE-751 24 Uppsala, Sweden
| | - Per E Andrén
- Department of Pharmaceutical Biosciences, Uppsala University, SE-751 24 Uppsala, Sweden.,Science for Life Laboratory, Spatial Mass Spectrometry, Uppsala University, SE-751 24 Uppsala, Sweden
| | - Erik T Jansson
- Department of Pharmaceutical Biosciences, Uppsala University, SE-751 24 Uppsala, Sweden
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9
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Jordan JS, Williams ER. Laser Heating Nanoelectrospray Emitters for Fast Protein Melting Measurements with Mass Spectrometry. Anal Chem 2022; 94:16894-16900. [DOI: 10.1021/acs.analchem.2c04204] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Affiliation(s)
- Jacob S. Jordan
- Department of Chemistry, University of California, Berkeley, California 94720, United States
| | - Evan R. Williams
- Department of Chemistry, University of California, Berkeley, California 94720, United States
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10
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Prabhu GRD, Yang TH, Shiu RT, Witek HA, Urban PL. Scanning pH-metry for Observing Reversibility in Protein Folding. Biochemistry 2022; 61:2377-2389. [PMID: 36251331 DOI: 10.1021/acs.biochem.2c00453] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
One of the main factors affecting protein structure in solution is pH. Traditionally, to study pH-dependent conformational changes in proteins, the concentration of the H+ ions is adjusted manually, complicating real-time analyses, hampering dynamic pH regulation, and consequently leading to a limited number of tested pH levels. Here, we present a programmable device, a scanning pH-meter, that can automatically generate different types of pH ramps and waveforms in a solution. A feedback loop algorithm calculates the required flow rates of the acid/base titrants, allowing one, for example, to generate periodic pH sine waveforms to study the reversibility of protein folding by fluorescence spectroscopy. Interestingly, for some proteins, the fluorescence intensity profiles recorded in such a periodically oscillating pH environment display hysteretic behavior indicating an asymmetry in the sequence of the protein unfolding/refolding events, which can most likely be attributed to their distinct kinetics. Another useful application of the scanning pH-meter concerns coupling it with an electrospray ionization mass spectrometer to observe pH-induced structural changes in proteins as revealed by their varying charge-state distributions. We anticipate a broad range of applications of the scanning pH-meter developed here, including protein folding studies, determination of the optimum pH for achieving maximum fluorescence intensity, and characterization of fluorescent dyes and other synthetic materials.
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Affiliation(s)
- Gurpur Rakesh D Prabhu
- Department of Chemistry, National Tsing Hua University, 101, Sec 2, Kuang-Fu Road, Hsinchu300044, Taiwan
- Department of Applied Chemistry, National Yang Ming Chiao Tung University, 1001 University Road, Hsinchu300093, Taiwan
| | - Tzu-Hsin Yang
- Department of Chemistry, National Tsing Hua University, 101, Sec 2, Kuang-Fu Road, Hsinchu300044, Taiwan
| | - Ruei-Tzung Shiu
- Department of Chemistry, National Tsing Hua University, 101, Sec 2, Kuang-Fu Road, Hsinchu300044, Taiwan
| | - Henryk A Witek
- Department of Applied Chemistry, National Yang Ming Chiao Tung University, 1001 University Road, Hsinchu300093, Taiwan
- Center for Emergent Functional Matter Science, National Yang Ming Chiao Tung University, 1001 University Road, Hsinchu300093, Taiwan
| | - Pawel L Urban
- Department of Chemistry, National Tsing Hua University, 101, Sec 2, Kuang-Fu Road, Hsinchu300044, Taiwan
- Frontier Research Center on Fundamental and Applied Sciences of Matters, National Tsing Hua University, 101, Sec 2, Kuang-Fu Road, Hsinchu300044, Taiwan
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11
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Gao XF, Cheng JC, Ye CL, Xiao S, Qiu ZM, Zhang X. Water promoted 9-fluorenylmethyloxycarbonyl detachment from amino acids in charged microdroplets. Org Biomol Chem 2022; 20:7001-7005. [PMID: 36000329 DOI: 10.1039/d2ob01438f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Aqueous microdroplets exhibit unique properties and can trigger reactions that do not occur in bulk solution. Herein, we have demonstrated that water, in microdroplets, can reduce the energy barrier for the lone H transfer of 9-fluorenylmethyloxycarbonyl and promote its detachment from the amino group. This strategy works on various amino acids and opens opportunities of aqueous microdroplets in triggering organic reactions.
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Affiliation(s)
- Xiao-Fei Gao
- Jiangxi Key Laboratory for Mass Spectrometry and Instrumentation, East China University of Technology, Nanchang 330013, China.
| | - Jin-Cai Cheng
- Jiangxi Key Laboratory for Mass Spectrometry and Instrumentation, East China University of Technology, Nanchang 330013, China.
| | - Chun-Lian Ye
- Jiangxi Key Laboratory for Mass Spectrometry and Instrumentation, East China University of Technology, Nanchang 330013, China.
| | - Shan Xiao
- Jiangxi Key Laboratory for Mass Spectrometry and Instrumentation, East China University of Technology, Nanchang 330013, China.
| | - Zai-Ming Qiu
- Jiangxi Key Laboratory for Mass Spectrometry and Instrumentation, East China University of Technology, Nanchang 330013, China.
| | - Xinglei Zhang
- Jiangxi Key Laboratory for Mass Spectrometry and Instrumentation, East China University of Technology, Nanchang 330013, China.
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12
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Abdelaty MSA. Schiff base post-polymerization based on temperature/pH environmentally responsive poly (NIPAAm-co-DMAMVA-co-S): characterization and the trigger of LCST behavioral changes. Polym Bull (Berl) 2022. [DOI: 10.1007/s00289-022-04327-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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13
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Chen M, Shang Y, Bai H, Ma Q. Electromembrane Extraction and Dual-Channel Nanoelectrospray Ionization Coupled with a Miniature Mass Spectrometer: Incorporation of a Dicationic Ionic Liquid-Induced Charge Inversion Strategy. Anal Chem 2022; 94:9472-9480. [PMID: 35737371 DOI: 10.1021/acs.analchem.2c01921] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Green analytical chemistry aims at developing analytical methods with minimum use and generation of hazardous substances for the protection of human health and the environment. To address this need, a green analytical protocol has been developed for the analysis of anionic compounds integrating electromembrane extraction (EME), dual-channel nanoelectrospray ionization (nanoESI), and a miniature mass spectrometer. Haloacetic acids (HAAs) have attracted considerable public concern due to their adverse effects on human health and were selected as model analytes for method development. A flat membrane EME device was developed and assembled in-house. Optimization of fundamental operational parameters was performed using single-factor test and response surface methodology. Both the EME acceptor phase and an imidazolium-based dicationic ionic liquid (DIL), 1,1-bis(3-methylimidazolium-1-yl) butylene difluoride (C4(MIM)2F2), were subjected to dual-channel nanoESI and miniature mass spectrometry analysis based on a charge inversion strategy, where positively charged complexes were formed. Enhancement in signal intensity by as much as 2 magnitudes was achieved in the positive-ion mode compared to the negative-ion mode in the absence of the dicationic ion-pairing agent. The developed protocol was validated, obtaining good recoveries ranging from 82.7 to 109.9% and satisfactory sensitivity with limits of detection (LODs) and quantitation (LOQs) in the ranges of 1-5 and 2-10 μg/L, respectively. The greenness of the analytical procedure was assessed with a calculated score of 0.71, indicating a high degree of greenness. The developed method was applied to the analysis of real environmental or municipal water samples (n = 16), exhibiting appealing potential for outside-the-laboratory applications.
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Affiliation(s)
- Meng Chen
- Key Laboratory of Consumer Product Quality Safety Inspection and Risk Assessment for State Market Regulation, Chinese Academy of Inspection and Quarantine, Beijing 100176, China
| | - Yuhan Shang
- Key Laboratory of Consumer Product Quality Safety Inspection and Risk Assessment for State Market Regulation, Chinese Academy of Inspection and Quarantine, Beijing 100176, China
| | - Hua Bai
- Key Laboratory of Consumer Product Quality Safety Inspection and Risk Assessment for State Market Regulation, Chinese Academy of Inspection and Quarantine, Beijing 100176, China
| | - Qiang Ma
- Key Laboratory of Consumer Product Quality Safety Inspection and Risk Assessment for State Market Regulation, Chinese Academy of Inspection and Quarantine, Beijing 100176, China
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14
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Peng Z, Luo Y, Song C, Zhang Y, Sun S, Yu A, Zhang W, Zhao W, Zhang S, Xie J. A novel methodology and strategy to detect low molecular aldehydes in beer based on charged microdroplet driving online derivatization and high resolution mass spectrometry. Food Chem 2022; 383:132380. [PMID: 35180599 DOI: 10.1016/j.foodchem.2022.132380] [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: 04/24/2021] [Revised: 01/11/2022] [Accepted: 02/05/2022] [Indexed: 11/25/2022]
Abstract
The concentration of aldehydes is one of the important indicators in the food quality and safety. To efficiently analyze the four aldehydes (methanal, ethanal, propanal and n-butanal) in beer, charged microdroplet driving online derivatization apparatus coupled with high resolution mass spectrometry was firstly developed. Utilizing the high-speed reaction accelerated by microdroplets, the offline derivative of aldehydes with 2,4-dinitrophenylhydrazine in bulk was transferred into online derivatization. The developed method featured acceptable linearities (R2 ≥ 0.95), high sensitivities (LODs at ng mL-1 level) and qualified precisions (RSDs ≤ 8.4 %) for target compounds. Four aldehydes with trace amount were successfully determined in beer. The results indicated that the novel online analytical strategy did not require complex sample preparation and could conduct simple, rapid, sensitive detection of small molecule aldehydes with high throughput in beer or even other food samples.
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Affiliation(s)
- Zifang Peng
- College of Chemistry, Zhengzhou University, Zhengzhou 450001, PR China
| | - Yake Luo
- College of Chemistry, Zhengzhou University, Zhengzhou 450001, PR China
| | - Chenchen Song
- College of Chemistry, Zhengzhou University, Zhengzhou 450001, PR China
| | - Yanhao Zhang
- State Key Laboratory of Environmental and Biological Analysis, Department of Chemistry, Hong Kong Baptist University, Hong Kong, PR China.
| | - Shihao Sun
- Center of Advanced Analysis and Gene Sequencing, Zhengzhou University, Zhengzhou 450001, PR China
| | - Ajuan Yu
- College of Chemistry, Zhengzhou University, Zhengzhou 450001, PR China
| | - Wenfen Zhang
- College of Chemistry, Zhengzhou University, Zhengzhou 450001, PR China
| | - Wuduo Zhao
- College of Chemistry, Zhengzhou University, Zhengzhou 450001, PR China.
| | - Shusheng Zhang
- College of Chemistry, Zhengzhou University, Zhengzhou 450001, PR China
| | - Jianping Xie
- Center of Advanced Analysis and Gene Sequencing, Zhengzhou University, Zhengzhou 450001, PR China
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15
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Heiss DR, Badu-Tawiah AK. In-Source Microdroplet Derivatization Using Coaxial Contained-Electrospray Mass Spectrometry for Enhanced Sensitivity in Saccharide Analysis. Anal Chem 2021; 93:16779-16786. [PMID: 34874718 DOI: 10.1021/acs.analchem.1c02897] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Online, droplet-based in-source chemical derivatization is accomplished using a coaxial-flow contained-electrospray ionization (contained-ESI) source to enhance sensitivity for the mass spectrometric analysis of saccharides. Derivatization is completed in microseconds by exploiting the reaction rate acceleration afforded by electrospray microdroplets. Significant improvements in method sensitivity are realized with minimal sample preparation and few resources when compared to traditional benchtop derivatizations. For this work, the formation of easily ionizable phenylboronate ester derivatives of several mono-, di-, and oligosaccharides is achieved. Various reaction parameters including concentration and pH were evaluated, and a Design of Experiments approach was used to optimize ion source parameters. Signal enhancements of greater than two orders of magnitude were observed for many mono- and disaccharides using in-source phenylboronic acid derivatization, resulting in parts-per-trillion (picomolar) limits of detection. In addition, amino sugars such as glucosamine, which do not ionize in negative mode, were detected at low parts-per-billion concentrations, and isobaric sugars such as lactose and sucrose were easily distinguished. The new in-source derivatization approach can be employed to expand the utility of ESI-MS analysis for compounds that historically experience limited sensitivity and detectability, while avoiding resource-intensive, bulk-phase derivatization procedures.
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Affiliation(s)
- Derik R Heiss
- Department of Chemistry, The Ohio State University, 100 W. 18th Avenue, Columbus, Ohio 43210, United States.,Battelle Memorial Institute, Columbus, Ohio 43201, United States
| | - Abraham K Badu-Tawiah
- Department of Chemistry, The Ohio State University, 100 W. 18th Avenue, Columbus, Ohio 43210, United States
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16
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Bennett JL, Nguyen GTH, Donald WA. Protein-Small Molecule Interactions in Native Mass Spectrometry. Chem Rev 2021; 122:7327-7385. [PMID: 34449207 DOI: 10.1021/acs.chemrev.1c00293] [Citation(s) in RCA: 31] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
Small molecule drug discovery has been propelled by the continual development of novel scientific methodologies to occasion therapeutic advances. Although established biophysical methods can be used to obtain information regarding the molecular mechanisms underlying drug action, these approaches are often inefficient, low throughput, and ineffective in the analysis of heterogeneous systems including dynamic oligomeric assemblies and proteins that have undergone extensive post-translational modification. Native mass spectrometry can be used to probe protein-small molecule interactions with unprecedented speed and sensitivity, providing unique insights into polydisperse biomolecular systems that are commonly encountered during the drug discovery process. In this review, we describe potential and proven applications of native MS in the study of interactions between small, drug-like molecules and proteins, including large multiprotein complexes and membrane proteins. Approaches to quantify the thermodynamic and kinetic properties of ligand binding are discussed, alongside a summary of gas-phase ion activation techniques that have been used to interrogate the structure of protein-small molecule complexes. We additionally highlight some of the key areas in modern drug design for which native mass spectrometry has elicited significant advances. Future developments and applications of native mass spectrometry in drug discovery workflows are identified, including potential pathways toward studying protein-small molecule interactions on a whole-proteome scale.
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Affiliation(s)
- Jack L Bennett
- School of Chemistry, University of New South Wales, Sydney, New South Wales 2052, Australia
| | - Giang T H Nguyen
- School of Chemistry, University of New South Wales, Sydney, New South Wales 2052, Australia
| | - William A Donald
- School of Chemistry, University of New South Wales, Sydney, New South Wales 2052, Australia
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17
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DeBastiani A, Majuta SN, Sharif D, Attanayake K, Li C, Li P, Valentine SJ. Characterizing Multidevice Capillary Vibrating Sharp-Edge Spray Ionization for In-Droplet Hydrogen/Deuterium Exchange to Enhance Compound Identification. ACS OMEGA 2021; 6:18370-18382. [PMID: 34308068 PMCID: PMC8296548 DOI: 10.1021/acsomega.1c02362] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/05/2021] [Accepted: 06/23/2021] [Indexed: 05/10/2023]
Abstract
Multidevice capillary vibrating sharp-edge spray ionization (cVSSI) source parameters have been examined to determine their effects on conducting in-droplet hydrogen/deuterium exchange (HDX) experiments. Control experiments using select compounds indicate that the observed differences in mass spectral isotopic distributions obtained upon initiation of HDX result primarily from solution-phase reactions as opposed to gas-phase exchange. Preliminary studies have determined that robust HDX can only be achieved with the application of same-polarity voltage to both the analyte and the deuterium oxide reagent (D2O) cVSSI devices. Additionally, a similar HDX reactivity dependence on the voltage applied to the D2O device for various analytes is observed. Analyte and reagent flow experiments show that, for the multidevice cVSSI setup employed, there is a nonlinear dependence on the D2O reagent flow rate; increasing the D2O reagent flow by 100% results in only an ∼10-20% increase in deuterium incorporation for this setup. Instantaneous (subsecond) response times have been demonstrated in the initiation or termination of HDX, which is achieved by turning on or off the reagent cVSSI device piezoelectric transducer. The ability to distinguish isomeric species by in-droplet HDX is presented. Finally, a demonstration of a three-component cVSSI device setup to perform multiple (successive or in combination) in-droplet chemistries to enhance compound ionization and identification is presented and a hypothetical metabolomics workflow consisting of successive multidevice activation is briefly discussed.
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18
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El-Baba TJ, Raab SA, Buckley RP, Brown CJ, Lutomski CA, Henderson LW, Woodall DW, Shen J, Trinidad JC, Niu H, Jarrold MF, Russell DH, Laganowsky A, Clemmer DE. Thermal Analysis of a Mixture of Ribosomal Proteins by vT-ESI-MS: Toward a Parallel Approach for Characterizing the Stabilitome. Anal Chem 2021; 93:8484-8492. [PMID: 34101419 PMCID: PMC8546744 DOI: 10.1021/acs.analchem.1c00772] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
The thermal stabilities of endogenous, intact proteins and protein assemblies in complex mixtures were characterized in parallel by means of variable-temperature electrospray ionization coupled to mass spectrometry (vT-ESI-MS). The method is demonstrated by directly measuring the melting transitions of seven proteins from a mixture of proteins derived from ribosomes. A proof-of-concept measurement of a fraction of an Escherichia coli lysate is provided to extend this approach to characterize the thermal stability of a proteome. As the solution temperature is increased, proteins and protein complexes undergo structural and organizational transitions; for each species, the folded ↔ unfolded and assembled ↔ disassembled populations are monitored based on changes in vT-ESI-MS charge state distributions and masses. The robustness of the approach illustrates a step toward the proteome-wide characterization of thermal stabilities and structural transitions-the stabilitome.
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Affiliation(s)
- Tarick J El-Baba
- Department of Chemistry, Indiana University, Bloomington, Indiana 47401, United States
| | - Shannon A Raab
- Department of Chemistry, Indiana University, Bloomington, Indiana 47401, United States
| | - Rachel P Buckley
- Department of Chemistry, Indiana University, Bloomington, Indiana 47401, United States
| | - Christopher J Brown
- Department of Chemistry, Indiana University, Bloomington, Indiana 47401, United States
| | - Corinne A Lutomski
- Department of Chemistry, Indiana University, Bloomington, Indiana 47401, United States
| | - Lucas W Henderson
- Department of Chemistry, Indiana University, Bloomington, Indiana 47401, United States
| | - Daniel W Woodall
- Department of Chemistry, Indiana University, Bloomington, Indiana 47401, United States
| | - Jiangchuan Shen
- Department of Molecular and Cellular Biochemistry, Indiana University, Bloomington, Indiana 47401, United States
| | - Jonathan C Trinidad
- Department of Chemistry, Indiana University, Bloomington, Indiana 47401, United States
| | - Hengyao Niu
- Department of Molecular and Cellular Biochemistry, Indiana University, Bloomington, Indiana 47401, United States
| | - Martin F Jarrold
- Department of Chemistry, Indiana University, Bloomington, Indiana 47401, United States
| | - David H Russell
- Department of Chemistry, Texas A&M University, College Station, Texas 77843, United States
| | - Arthur Laganowsky
- Department of Chemistry, Texas A&M University, College Station, Texas 77843, United States
| | - David E Clemmer
- Department of Chemistry, Indiana University, Bloomington, Indiana 47401, United States
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19
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Ray Chowdhuri A, Spoorthi BK, Mondal B, Bose P, Bose S, Pradeep T. Ambient microdroplet annealing of nanoparticles. Chem Sci 2021; 12:6370-6377. [PMID: 34084436 PMCID: PMC8115297 DOI: 10.1039/d1sc00112d] [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] [Indexed: 11/21/2022] Open
Abstract
Conversion of polydisperse nanoparticles to their monodisperse analogues and formation of organized superstructures using them involve post synthetic modifications, and the process is generally slow. We show that ambient electrospray of preformed polydisperse nanoparticles makes them monodisperse and the product nanoparticles self-assemble spontaneously to form organized films, all within seconds. This phenomenon has been demonstrated with thiol-protected polydisperse silver nanoparticles of 15 ± 10 nm diameter. Uniform silver nanoparticles of 4.0 ± 0.5 nm diameter were formed after microdroplet spray, and this occurred without added chemicals, templates, and temperature, and within the time needed for electrospray, which was of the order of seconds. Well organized nanoparticle assemblies were obtained from such uniform particles. A home-made and simple nanoelectrospray set-up produced charged microdroplets for the generation of such nanostructures, forming cm2 areas of uniform nanoparticles. A free-standing thin film of monodisperse silver nanoparticles was also made on a liquid surface by controlling the electrospray conditions. This unique method may be extended for the creation of advanced materials of many kinds. Polydisperse silver nanoparticles were converted to a highly ordered assembly of nanoparticles by microdroplet-induced chemistry, under ambient conditions, within seconds.![]()
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Affiliation(s)
- Angshuman Ray Chowdhuri
- DST Unit of Nanoscience (DST UNS), Thematic Unit of Excellence (TUE), Department of Chemistry, Indian Institute of Technology Madras Chennai 600 036 India
| | - B K Spoorthi
- DST Unit of Nanoscience (DST UNS), Thematic Unit of Excellence (TUE), Department of Chemistry, Indian Institute of Technology Madras Chennai 600 036 India
| | - Biswajit Mondal
- DST Unit of Nanoscience (DST UNS), Thematic Unit of Excellence (TUE), Department of Chemistry, Indian Institute of Technology Madras Chennai 600 036 India
| | - Paulami Bose
- DST Unit of Nanoscience (DST UNS), Thematic Unit of Excellence (TUE), Department of Chemistry, Indian Institute of Technology Madras Chennai 600 036 India
| | - Sandeep Bose
- DST Unit of Nanoscience (DST UNS), Thematic Unit of Excellence (TUE), Department of Chemistry, Indian Institute of Technology Madras Chennai 600 036 India
| | - Thalappil Pradeep
- DST Unit of Nanoscience (DST UNS), Thematic Unit of Excellence (TUE), Department of Chemistry, Indian Institute of Technology Madras Chennai 600 036 India
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20
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Freitas D, Chen X, Cheng H, Davis A, Fallon B, Yan X. Recent Advances of In-Source Electrochemical Mass Spectrometry. Chempluschem 2021; 86:434-445. [PMID: 33689239 DOI: 10.1002/cplu.202100030] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2021] [Revised: 03/03/2021] [Indexed: 12/16/2022]
Abstract
Hyphenation of electrochemistry (EC) and mass spectrometry has become a powerful tool to study redox processes. Approaches that can achieve this hyphenation include integrating chromatography/electrophoresis between electroinduced redox reactions and detection of products, coupling an EC flow cell to a mass spectrometer, and performing electrochemical reactions inside the ion source of a mass spectrometer. The first two approaches have been well reviewed elsewhere. This Minireview highlights the inherent electrochemical properties of many mass spectrometry ion sources and their roles in the coupling of electrochemistry and mass spectrometric analysis. Development of modified ion sources that allow the compatibility of electrochemistry with ionization processes is also surveyed. Applications of different in-source electrochemical devices are provided including intermediate capturing, bioanalytical studies, nanoparticle formation, electrosynthesis, and electrode imaging.
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Affiliation(s)
- Dallas Freitas
- Department of Chemistry, Texas A&M University, 580 Ross St., College Station, TX 77843, USA
| | - Xi Chen
- Department of Chemistry, Texas A&M University, 580 Ross St., College Station, TX 77843, USA
| | - Heyong Cheng
- Department of Chemistry, Texas A&M University, 580 Ross St., College Station, TX 77843, USA
| | - Austin Davis
- Department of Chemistry, Texas A&M University, 580 Ross St., College Station, TX 77843, USA
| | - Blake Fallon
- Department of Chemistry, Texas A&M University, 580 Ross St., College Station, TX 77843, USA
| | - Xin Yan
- Department of Chemistry, Texas A&M University, 580 Ross St., College Station, TX 77843, USA
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21
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Jordan JS, Williams ER. Effects of Electrospray Droplet Size on Analyte Aggregation: Evidence for Serine Octamer in Solution. Anal Chem 2021; 93:1725-1731. [PMID: 33369386 DOI: 10.1021/acs.analchem.0c04343] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Spraying solutions of serine under a wide variety of conditions results in unusually abundant gaseous octamer clusters that exhibit significant homochiral specificity, but the extent to which these clusters exist in solution or are formed by clustering during droplet evaporation has been debated. Electrospray ionization emitters with tip sizes between 210 nm and 9.2 μm were used to constrain the number of serine molecules that droplets initially contain. Protonated octamer was observed for all tip sizes with 10 mM serine solution, but the abundance decreases from 10% of the serine population at the largest tip size to ∼5.6% for the two smallest tip sizes. At 100 μM, the population abundance of the protonated serine octamer decreases from 1% to 0.6% from the largest to the smallest tip size, respectively. At 100 μM, fewer than 10% of the initial droplets should contain even a single analyte molecule with 210 nm emitter tips. These results indicate that the majority of protonated octamer observed in mass spectra under previous conditions is formed by clustering inside the electrospray droplet, but ≤5.6% and ∼0.6% of serine exists as an octamer complex in 10 mM and 100 μM solutions, respectively. These results show that aggregation occurs in large droplets, but this aggregation can be eliminated using emitters with sufficiently small tips. Use of these emitters with small tips is advantageous for clearly distinguishing between species that exist in solution and species formed by clustering inside droplets as solvent evaporation occurs.
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Affiliation(s)
- Jacob S Jordan
- Department of Chemistry, University of California, Berkeley, California 94720, United States
| | - Evan R Williams
- Department of Chemistry, University of California, Berkeley, California 94720, United States
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22
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Rovelli G, Jacobs MI, Willis MD, Rapf RJ, Prophet AM, Wilson KR. A critical analysis of electrospray techniques for the determination of accelerated rates and mechanisms of chemical reactions in droplets. Chem Sci 2020; 11:13026-13043. [PMID: 34094487 PMCID: PMC8163298 DOI: 10.1039/d0sc04611f] [Citation(s) in RCA: 54] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2020] [Accepted: 10/25/2020] [Indexed: 12/14/2022] Open
Abstract
Electrospray and Electrosonic Spray Ionization Mass Spectrometry (ESI-MS and ESSI-MS) have been widely used to report evidence that many chemical reactions in micro- and nano-droplets are dramatically accelerated by factors of ∼102 to 106 relative to macroscale bulk solutions. Despite electrospray's relative simplicity to both generate and detect reaction products in charged droplets using mass spectrometry, substantial complexity exists in how the electrospray process itself impacts the interpretation of the mechanism of these observed accelerated rates. ESI and ESSI are both coupled multi-phase processes, in which analytes in small charged droplets are transferred and detected as gas-phase ions with a mass spectrometer. As such, quantitative examination is needed to evaluate the impact of multiple experimental factors on the magnitude and mechanisms of reaction acceleration. These include: (1) evaporative concentration of reactants as a function of droplet size and initial concentration, (2) competition from gas-phase chemistry and reactions on experimental surfaces, (3) differences in ionization efficiency and ion transmission and (4) droplet charge. We examine (1-4) using numerical models, new ESI/ESSI-MS experimental data, and prior literature to assess the limitations of these approaches and the experimental best practices required to robustly interpret acceleration factors in micro- and nano-droplets produced by ESI and ESSI.
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Affiliation(s)
- Grazia Rovelli
- Chemical Sciences Division, Lawrence Berkeley National Laboratory Berkeley 94720 CA USA
| | - Michael I Jacobs
- Chemical Sciences Division, Lawrence Berkeley National Laboratory Berkeley 94720 CA USA
- Department of Chemistry, University of California Berkeley 94720 CA USA
| | - Megan D Willis
- Chemical Sciences Division, Lawrence Berkeley National Laboratory Berkeley 94720 CA USA
| | - Rebecca J Rapf
- Chemical Sciences Division, Lawrence Berkeley National Laboratory Berkeley 94720 CA USA
| | - Alexander M Prophet
- Chemical Sciences Division, Lawrence Berkeley National Laboratory Berkeley 94720 CA USA
- Department of Chemistry, University of California Berkeley 94720 CA USA
| | - Kevin R Wilson
- Chemical Sciences Division, Lawrence Berkeley National Laboratory Berkeley 94720 CA USA
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23
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Wei Z, Li Y, Cooks RG, Yan X. Accelerated Reaction Kinetics in Microdroplets: Overview and Recent Developments. Annu Rev Phys Chem 2020; 71:31-51. [PMID: 32312193 DOI: 10.1146/annurev-physchem-121319-110654] [Citation(s) in RCA: 199] [Impact Index Per Article: 49.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Various organic reactions, including important synthetic reactions involving C-C, C-N, and C-O bond formation as well as reactions of biomolecules, are accelerated when the reagents are present in sprayed or levitated microdroplets or in thin films. The reaction rates increase by orders of magnitude with decreasing droplet size or film thickness. The effect is associated with reactions at the solution-air interface. A key factor is partial solvation of the reagents at the interface, which reduces the critical energy for reaction. This phenomenon is of intrinsic interest and potentially of practical value as a simple, rapid method of performing small-scale synthesis.
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Affiliation(s)
- Zhenwei Wei
- Department of Chemistry, Purdue University, West Lafayette, Indiana 47907, USA;
| | - Yangjie Li
- Department of Chemistry, Purdue University, West Lafayette, Indiana 47907, USA;
| | - R Graham Cooks
- Department of Chemistry, Purdue University, West Lafayette, Indiana 47907, USA;
| | - Xin Yan
- Department of Chemistry, Texas A&M University, College Station, Texas 77842, USA;
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24
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Prabhu GRD, Ponnusamy VK, Witek HA, Urban PL. Sample Flow Rate Scan in Electrospray Ionization Mass Spectrometry Reveals Alterations in Protein Charge State Distribution. Anal Chem 2020; 92:13042-13049. [PMID: 32893617 DOI: 10.1021/acs.analchem.0c01945] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Sample flow rate is one of the parameters that influence the sensitivity of electrospray ionization (ESI) mass spectrometry. By varying the sample flow rate, initial droplets of different sizes can be generated. Protein molecules in small droplets may form gas-phase ions earlier than the ones in large droplets. Here, we have systematically studied the influence of sample flow rate on the ESI charge state distributions (CSDs) of model proteins. A dedicated programmable sample flow rate scanner was used to infuse protein samples at different flow rates into a mass spectrometer. The synergistic influence of sample flow rate and various electrolytes (ammonium acetate, ammonium bicarbonate, ammonium formate, and piperidine) was studied. Significant alterations to the CSDs with increasing flow rate were observed. For example, in the presence of ammonium acetate, at low flow rates, lower charge states of proteins showed high intensities, while at high flow rates, ions related to higher charge states of proteins dominated the spectra. On the other hand, in the presence of piperidine, a significant reduction in the ion currents of all charge states was observed during the flow rate scan. Our observations suggest that at low flow rates the protein molecules follow a charged residue model of ionization mechanism, and at high flow rates-due to structural changes in protein molecules in large ESI droplets-the charged residue and chain ejection models can possibly coexist. We propose the use of sample flow rate scan as a way to reveal the influence of flow rate on the CSDs of the studied proteins.
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Affiliation(s)
- Gurpur Rakesh D Prabhu
- Department of Applied Chemistry, National Chiao Tung University, 1001 University Road, Hsinchu 30010, Taiwan.,Department of Chemistry, National Tsing Hua University, 101, Section 2, Kuang-Fu Road, Hsinchu 30013, Taiwan
| | - Vinoth Kumar Ponnusamy
- Department of Medicinal and Applied Chemistry & Research Center for Environmental Medicine, Kaohsiung Medical University, 100 Shih-Chuan 1st Road, Kaohsiung 807, Taiwan.,Department of Medical Research, Kaohsiung Medical University Hospital, 100 Shih-Chuan 1st Road, Kaohsiung 807, Taiwan
| | - Henryk A Witek
- Department of Applied Chemistry, National Chiao Tung University, 1001 University Road, Hsinchu 30010, Taiwan.,Center for Emergent Functional Matter Science, National Chiao Tung University, 1001 University Road, Hsinchu 30010, Taiwan
| | - Pawel L Urban
- Department of Chemistry, National Tsing Hua University, 101, Section 2, Kuang-Fu Road, Hsinchu 30013, Taiwan.,Frontier Research Center on Fundamental and Applied Sciences of Matters, National Tsing Hua University, 101, Section 2, Kuang-Fu Road, Hsinchu 30013, Taiwan
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25
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Li Y, Meng L, Wang G, Zhou X, Ouyang Z, Nie Z. A Gas-Phase Reaction Accelerator Using Vortex Flows. Anal Chem 2020; 92:12049-12054. [PMID: 32867491 DOI: 10.1021/acs.analchem.0c02672] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Gas-phase microdroplets have been increasingly used for reaction acceleration. Here, we report the development of a vortex tube as a reaction accelerator. Three types of reactions, viz., aromatization, amination isomerization, and acid-induced cytochrome c unfolding were used to characterize the performance of the vortex tube. During ion transfer from a nanoelectrospray ionization (nanoESI) source to the mass spectrometry (MS) inlet, the generated vortex flows helped droplet desolvation and ion confinement and thus improved the MS intensity by 2-3 orders of magnitude compared with that when the vortex tube was not applied. Like the stirring effect in the bulk phase, the reactants were more sufficiently mixed and reacted in vortices. Therefore, with the same reaction distance, a 2-3-fold improvement of conversion ratios was observed by using the vortices. Notably, the vortex tube enabled the use of flow rate to control the reaction time for ∼60 μs, which was useful for precise control of reaction progress. As a demonstration, the intermediates of the amination isomerization were tracked and the equilibrium constant and rate constant of the cytochrome c unfolding were determined.
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Affiliation(s)
- Yuze Li
- State Key Laboratory of Precision Measurement Technology and Instruments, Department of Precision Instrument, Tsinghua University, Beijing 10084, China.,Beijing National Laboratory for Molecular Sciences, Key Laboratory of Analytical Chemistry for Living Biosystems, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China.,University of Chinese Academy of Sciences, Beijing 100049, China
| | - Lingwei Meng
- Beijing National Laboratory for Molecular Sciences, Key Laboratory of Analytical Chemistry for Living Biosystems, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China.,University of Chinese Academy of Sciences, Beijing 100049, China
| | - Guanghui Wang
- National Center for Mass Spectrometry in Beijing, Beijing 100190, China
| | - Xiaoyu Zhou
- State Key Laboratory of Precision Measurement Technology and Instruments, Department of Precision Instrument, Tsinghua University, Beijing 10084, China
| | - Zheng Ouyang
- State Key Laboratory of Precision Measurement Technology and Instruments, Department of Precision Instrument, Tsinghua University, Beijing 10084, China
| | - Zongxiu Nie
- Beijing National Laboratory for Molecular Sciences, Key Laboratory of Analytical Chemistry for Living Biosystems, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China.,University of Chinese Academy of Sciences, Beijing 100049, China.,National Center for Mass Spectrometry in Beijing, Beijing 100190, China
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26
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Wu L, Yao YN, Yuan ZC, DI D, Li L, Hu B. Direct Detection of Lysozyme in Viscous Raw Hen Egg White Binding to Sodium Dodecyl Sulfonate by Reactive Wooden-tip Electrospray Ionization Mass Spectrometry. ANAL SCI 2020; 36:341-346. [PMID: 31656247 DOI: 10.2116/analsci.19p288] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Direct characterization of native protein binding to ligands in raw biological samples is a challenging task, because the ligand solution might induce proteins to aggregation, flocculation and denaturation. In this work, we developed a reactive wooden-tip electrospray ionization mass spectrometry (ESI-MS) for formation and characterization of protein-ligand complexes upon rapid mixing in electrospray droplets. Raw viscous hen egg white (HEW) was directly loaded onto a wooden tip to induce spray ionization, and sodium dodecyl sulfonate (SDS) solution was directly loaded into the HEW spray by a pipette tip, and thus lysozyme-DS complexes were then formed in the electrospray droplets and were detected subsequently by mass spectrometry. The new approach was successfully applied to investigate interaction of SDS and native lysozyme in electrospray droplets of standard solution and raw egg white. Our results showed that wooden-tip ESI-MS is a promising method to form and characterize protein-ligand complexes.
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Affiliation(s)
- Lin Wu
- Institute of Mass Spectrometry and Atmospheric Environment, Guangdong Provincial Engineering Research Center for On-line Source Apportionment System of Air Pollution, Jinan University
| | - Ya-Nan Yao
- Institute of Mass Spectrometry and Atmospheric Environment, Guangdong Provincial Engineering Research Center for On-line Source Apportionment System of Air Pollution, Jinan University
| | - Zi-Cheng Yuan
- Institute of Mass Spectrometry and Atmospheric Environment, Guangdong Provincial Engineering Research Center for On-line Source Apportionment System of Air Pollution, Jinan University
| | - Dandan DI
- Institute of Mass Spectrometry and Atmospheric Environment, Guangdong Provincial Engineering Research Center for On-line Source Apportionment System of Air Pollution, Jinan University
| | - Lei Li
- Institute of Mass Spectrometry and Atmospheric Environment, Guangdong Provincial Engineering Research Center for On-line Source Apportionment System of Air Pollution, Jinan University.,Guangzhou Hexin Instrument Co., Ltd
| | - Bin Hu
- Institute of Mass Spectrometry and Atmospheric Environment, Guangdong Provincial Engineering Research Center for On-line Source Apportionment System of Air Pollution, Jinan University
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27
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Ventouri IK, Malheiro DBA, Voeten RLC, Kok S, Honing M, Somsen GW, Haselberg R. Probing Protein Denaturation during Size-Exclusion Chromatography Using Native Mass Spectrometry. Anal Chem 2020; 92:4292-4300. [PMID: 32107919 PMCID: PMC7081181 DOI: 10.1021/acs.analchem.9b04961] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
![]()
Size-exclusion chromatography
employing aqueous mobile phases with
volatile salts at neutral pH combined with electrospray-ionization
mass spectrometry (SEC-ESI-MS) is a useful tool to study proteins
in their native state. However, whether the applied eluent conditions
actually prevent protein–stationary phase interactions, and/or
protein denaturation, often is not assessed. In this study, the effects
of volatile mobile phase additives on SEC retention and ESI of proteins
were thoroughly investigated. Myoglobin was used as the main model
protein, and eluents of varying ionic strength and pH were applied.
The degree of interaction between protein and stationary phase was
evaluated by calculating the SEC distribution coefficient. Protein-ion
charge state distributions obtained during offline and online native
ESI-MS were used to monitor alterations in protein structure. Interestingly,
most of the supposedly mild eluent compositions induced nonideal SEC
behavior and/or protein unfolding. SEC experiments revealed that the
nature, ionic strength, and pH of the eluent affected protein retention.
Protein–stationary phase interactions were effectively avoided
using ammonium acetate at ionic strengths above 0.1 M. Direct-infusion
ESI-MS showed that the tested volatile eluent salts seem to follow
the Hofmeister series: no denaturation was induced using ammonium
acetate (kosmotropic), whereas ammonium formate and bicarbonate (both
chaotropic) caused structural changes. Using a mobile phase of 0.2
M ammonium acetate (pH 6.9), several proteins (i.e., myoglobin, carbonic
anhydrase, and cytochrome c) could be analyzed by SEC-ESI-MS using
different column chemistries without compromising their native state.
Overall, with SEC-ESI-MS, the effect of nonspecific interactions between
protein and stationary phase on the protein structure can be studied,
even revealing gradual structural differences along a peak.
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Affiliation(s)
- Iro K Ventouri
- Division of Bioanalytical Chemistry, AIMMS Amsterdam Institute of Molecular and Life Sciences, Vrije Universiteit Amsterdam, 1081 HV Amsterdam, The Netherlands.,Centre for Analytical Sciences Amsterdam, 1098XH Amsterdam, The Netherlands.,TI-COAST, 1098 XH Amsterdam, The Netherlands.,Analytical Chemistry Group, van't Hoff Institute for Molecular Sciences, University of Amsterdam, PO Box 94720, 1090 GE Amsterdam, The Netherlands
| | - Daniel B A Malheiro
- Division of Bioanalytical Chemistry, AIMMS Amsterdam Institute of Molecular and Life Sciences, Vrije Universiteit Amsterdam, 1081 HV Amsterdam, The Netherlands.,TI-COAST, 1098 XH Amsterdam, The Netherlands
| | - Robert L C Voeten
- Division of Bioanalytical Chemistry, AIMMS Amsterdam Institute of Molecular and Life Sciences, Vrije Universiteit Amsterdam, 1081 HV Amsterdam, The Netherlands.,Centre for Analytical Sciences Amsterdam, 1098XH Amsterdam, The Netherlands.,TI-COAST, 1098 XH Amsterdam, The Netherlands
| | - Sander Kok
- DSM Materials Science Center, 6167 RD Geleen, The Netherlands
| | - Maarten Honing
- Division of Bioanalytical Chemistry, AIMMS Amsterdam Institute of Molecular and Life Sciences, Vrije Universiteit Amsterdam, 1081 HV Amsterdam, The Netherlands.,DSM Materials Science Center, 6167 RD Geleen, The Netherlands
| | - Govert W Somsen
- Division of Bioanalytical Chemistry, AIMMS Amsterdam Institute of Molecular and Life Sciences, Vrije Universiteit Amsterdam, 1081 HV Amsterdam, The Netherlands.,Centre for Analytical Sciences Amsterdam, 1098XH Amsterdam, The Netherlands
| | - Rob Haselberg
- Division of Bioanalytical Chemistry, AIMMS Amsterdam Institute of Molecular and Life Sciences, Vrije Universiteit Amsterdam, 1081 HV Amsterdam, The Netherlands.,Centre for Analytical Sciences Amsterdam, 1098XH Amsterdam, The Netherlands
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28
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Poltash ML, McCabe JW, Shirzadeh M, Laganowsky A, Russell DH. Native IM-Orbitrap MS: Resolving What Was Hidden. Trends Analyt Chem 2020; 124:115533. [PMID: 32189816 PMCID: PMC7079669 DOI: 10.1016/j.trac.2019.05.035] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Native ion mobility-mass spectrometry (IM-MS) is an emerging biophysical approach to probe the intricate details of protein structure and function. The instrument design enables measurements of accurate first-principle determinations of rotationally-averaged ion-neutral collision cross sections coupled with high-mass, high-resolution mass measurement capabilities of Orbitrap MS. The inherent duty-cycle mismatch between drift tube IM and Orbitrap MS is alleviated by operating the drift tube in a frequency modulated mode while continuously acquiring mass spectra with the Orbitrap MS. Fourier transform of the resulting time-domain signal, i.e., ion abundances as a function of the modulation frequency, yields a frequency domain spectrum that is then converted (s-1 to s) to IM drift time. This multiplexed approach allows for a duty-cycle of 25% compared to <1% for traditional "pulse-and-wait" IM-ToF-MS. Improvements in mobility and mass resolution of the IM-Orbitrap allows for accurate analysis of intact protein complexes and the possibility of capturing protein dynamics.
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Affiliation(s)
- Michael L. Poltash
- Department of Chemistry, Texas A&M University, 3255 TAMU, College Station, Texas 77843
| | - Jacob W. McCabe
- Department of Chemistry, Texas A&M University, 3255 TAMU, College Station, Texas 77843
| | - Mehdi Shirzadeh
- Department of Chemistry, Texas A&M University, 3255 TAMU, College Station, Texas 77843
| | - Arthur Laganowsky
- Department of Chemistry, Texas A&M University, 3255 TAMU, College Station, Texas 77843
| | - David H. Russell
- Department of Chemistry, Texas A&M University, 3255 TAMU, College Station, Texas 77843
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29
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Nie H, Wei Z, Qiu L, Chen X, Holden DT, Cooks RG. High-yield gram-scale organic synthesis using accelerated microdroplet/thin film reactions with solvent recycling. Chem Sci 2020; 11:2356-2361. [PMID: 34084396 PMCID: PMC8157326 DOI: 10.1039/c9sc06265c] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
A closed system has been designed to perform microdroplet/thin film reactions with solvent recycling capabilities for gram-scale chemical synthesis. Claisen-Schmidt, Schiff base, Katritzky and Suzuki coupling reactions show acceleration factors relative to bulk of 15 to 7700 times in this droplet spray system. These values are much larger than those reported previously for the same reactions in microdroplet/thin film reaction systems. The solvent recycling mode of the new system significantly improves the reaction yield, especially for reactions with smaller reaction acceleration factors. The microdroplet/thin film reaction yield improved on recycling from 33% to 86% and from 32% to 72% for the Katritzky and Suzuki coupling reactions, respectively. The Claisen-Schmidt reaction was chosen to test the capability of this system in gram scale syntheses and rates of 3.18 g per h and an isolated yield of 87% were achieved.
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Affiliation(s)
- Honggang Nie
- Aston Labs, Department of Chemistry, Purdue University 560 Oval Drive West Lafayette IN 47906-1393 USA .,Beijing National Laboratory for Molecular Sciences, College of Chemistry and Molecular Engineering, Peking University Beijing 100871 P. R. China
| | - Zhenwei Wei
- Aston Labs, Department of Chemistry, Purdue University 560 Oval Drive West Lafayette IN 47906-1393 USA
| | - Lingqi Qiu
- Aston Labs, Department of Chemistry, Purdue University 560 Oval Drive West Lafayette IN 47906-1393 USA
| | - Xingshuo Chen
- Aston Labs, Department of Chemistry, Purdue University 560 Oval Drive West Lafayette IN 47906-1393 USA
| | - Dylan T Holden
- Aston Labs, Department of Chemistry, Purdue University 560 Oval Drive West Lafayette IN 47906-1393 USA
| | - R Graham Cooks
- Aston Labs, Department of Chemistry, Purdue University 560 Oval Drive West Lafayette IN 47906-1393 USA
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30
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Kim HJ, Gallagher ES. Achieving multiple hydrogen/deuterium exchange timepoints of carbohydrate hydroxyls using theta-electrospray emitters. Analyst 2020; 145:3056-3063. [DOI: 10.1039/d0an00135j] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Microsecond reaction times for in-droplet hydrogen/deuterium exchange of carbohydrate hydroxyls have been varied by changing the opening sizes of theta-electrospray emitters.
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Affiliation(s)
- H. Jamie Kim
- Department of Chemistry and Biochemistry
- Baylor University
- Waco
- USA
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31
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Aydin F, Zhan C, Ritt C, Epsztein R, Elimelech M, Schwegler E, Pham TA. Similarities and differences between potassium and ammonium ions in liquid water: a first-principles study. Phys Chem Chem Phys 2020; 22:2540-2548. [DOI: 10.1039/c9cp06163k] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Understanding ion solvation in liquid water is critical in optimizing materials for a wide variety of emerging technologies, including water desalination and purification.
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Affiliation(s)
- Fikret Aydin
- Lawrence Livermore National Laboratory
- Livermore
- USA
| | - Cheng Zhan
- Lawrence Livermore National Laboratory
- Livermore
- USA
| | - Cody Ritt
- Department of Chemical and Environmental Engineering
- Yale University
- New Haven
- USA
| | - Razi Epsztein
- Department of Chemical and Environmental Engineering
- Yale University
- New Haven
- USA
- Faculty of Civil and Environmental Engineering
| | - Menachem Elimelech
- Department of Chemical and Environmental Engineering
- Yale University
- New Haven
- USA
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32
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Lawal RO, Donnarumma F, Murray KK. Electrospray Photochemical Oxidation of Proteins. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2019; 30:2196-2199. [PMID: 31489562 PMCID: PMC6832858 DOI: 10.1007/s13361-019-02313-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/30/2019] [Revised: 07/18/2019] [Accepted: 08/10/2019] [Indexed: 06/10/2023]
Abstract
Photooxidation of peptides and proteins by pulsed ultraviolet laser irradiation of an electrospray in the ion source of a mass spectrometer was demonstrated. A 193-nm excimer laser at 1.5-mJ pulse energy was focused with a cylindrical lens at the exit of a nanoelectrospray capillary and ions were sampled into a quadrupole time-of-flight mass spectrometer. A solution containing a peptide or protein and hydrogen peroxide was infused into the spray at a flow rate of 1 μL/min using a syringe pump. The laser creates OH radicals directly in the spray which modify biomolecules within the spray droplet. These results indicate that photochemical oxidation of proteins can be initiated directly within electrospray droplets and detected by mass spectrometry.
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Affiliation(s)
- Remilekun O Lawal
- Department of Chemistry, Louisiana State University, Baton Rouge, LA, 70803, USA
| | - Fabrizio Donnarumma
- Department of Chemistry, Louisiana State University, Baton Rouge, LA, 70803, USA
| | - Kermit K Murray
- Department of Chemistry, Louisiana State University, Baton Rouge, LA, 70803, USA.
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33
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Tu A, Muddiman DC. Internal Energy Deposition in Infrared Matrix-Assisted Laser Desorption Electrospray Ionization With and Without the Use of Ice as a Matrix. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2019; 30:2380-2391. [PMID: 31502226 PMCID: PMC6937789 DOI: 10.1007/s13361-019-02323-2] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/28/2019] [Revised: 08/13/2019] [Accepted: 08/14/2019] [Indexed: 05/08/2023]
Abstract
The internal energy deposited into analytes during the ionization process largely influences the extent of fragmentation, thus the appearance of the resulting mass spectrum. The internal energy distributions of a series of para-substituted benzyl pyridinium cations in liquid and solid-state generated by infrared matrix-assisted laser desorption electrospray ionization (IR-MALDESI) were measured using the survival yield method, of which results were subsequently compared with conventional electrospray ionization (ESI). The comparable mean internal energy values (e.g., 1.8-1.9 eV at a collision energy of 15 eV) and peak widths obtained with IR-MALDESI and ESI support that IR-MALDESI are essentially a soft ionization technique where analytes do not gain considerable internal energy during the laser-induced desorption process and/or lose energy during uptake into charged electrospray droplets. An unusual fragment ion, protonated pyridine, was only found for solid IR-MALDESI at relatively high collision energies, which is presumably resulted from direct ionization of the pre-charged analytes in form of salts. Analysis of tissue with an ice layer consistently yielded ion populations with higher internal energy than its counterpart without an ice layer, likely due to a substantially enhanced number of IR absorbers with ice. Further measurements with holo-myoglobin show that IR-MALDESI-MS retains the noncovalently bound heme-protein complexes under both native-like and denaturing conditions, while complete loss of the heme group occurred in denaturing ESI-MS, showing that the softness of IR-MALDESI is equivalent or superior to ESI for biomolecules.
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Affiliation(s)
- Anqi Tu
- FTMS Laboratory for Human Health Research, Department of Chemistry, North Carolina State University, Raleigh, NC, 27695, USA
| | - David C Muddiman
- FTMS Laboratory for Human Health Research, Department of Chemistry, North Carolina State University, Raleigh, NC, 27695, USA.
- Molecular Education, Technology and Research Innovation Center (METRIC), North Carolina State University, Raleigh, NC, 27695, USA.
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34
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Liu C, Li J, Chen H, Zare RN. Scale-up of microdroplet reactions by heated ultrasonic nebulization. Chem Sci 2019; 10:9367-9373. [PMID: 32110301 PMCID: PMC7017870 DOI: 10.1039/c9sc03701b] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2019] [Accepted: 08/19/2019] [Indexed: 12/24/2022] Open
Abstract
Dramatically higher rates for a variety of chemical reactions have been reported in microdroplets compared with those in the liquid bulk phase. However, the scale-up of microdroplet chemical synthesis has remained a major challenge to the practical application of microdroplet chemistry. Heated ultrasonic nebulization (HUN) was found as a new way for scaling up chemical synthesis in microdroplets. Four reactions were examined, a base-catalyzed Claisen-Schmidt condensation, an oximation reaction from a ketone, a two-phase oxidation reaction without the use of a phase-transfer-catalyst, and an Eschenmoser coupling reaction. These reactions show acceleration of one to three orders of magnitude (122, 23, 6536, and 62) in HUN microdroplets compared to the same reactions in bulk solution. Then, using the present method, the scale-up of the reactions was achieved at an isolated rate of 19 mg min-1 for the product of the Claisen-Schmidt condensation, 21 mg min-1 for the synthesis of benzophenone oxime from benzophenone, 31 mg min-1 for the synthesis of 4-methoxybenzaldehyde from 4-methoxybenzyl alcohol, and 40 mg min-1 for the enaminone product of the Eschenmoser coupling reaction.
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Affiliation(s)
- Chengyuan Liu
- Department of Chemistry , Fudan University , Shanghai 200438 , China .
| | - Jia Li
- Department of Chemistry , Fudan University , Shanghai 200438 , China .
| | - Hao Chen
- Department of Chemistry & Environmental Science , New Jersey Institute of Technology , Newark , NJ 07102 , USA
| | - Richard N Zare
- Department of Chemistry , Fudan University , Shanghai 200438 , China .
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35
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Majuta SN, Li C, Jayasundara K, Kiani Karanji A, Attanayake K, Ranganathan N, Li P, Valentine SJ. Rapid Solution-Phase Hydrogen/Deuterium Exchange for Metabolite Compound Identification. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2019; 30:1102-1114. [PMID: 30980382 DOI: 10.1007/s13361-019-02163-0] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/09/2019] [Revised: 02/15/2019] [Accepted: 02/16/2019] [Indexed: 05/25/2023]
Abstract
Rapid, solution-phase hydrogen/deuterium exchange (HDX) coupled with mass spectrometry (MS) is demonstrated as a means for distinguishing small-molecule metabolites. HDX is achieved using capillary vibrating sharp-edge spray ionization (cVSSI) to allow sufficient time for reagent mixing and exchange in micrometer-sized droplets. Different compounds are observed to incorporate deuterium with varying efficiencies resulting in unique isotopic patterns as revealed in the MS spectra. Using linear regression techniques, parameters representing contribution to exchange by different hydrogen types can be computed. In this proof-of-concept study, the exchange parameters are shown to be useful in the retrodiction of the amount of deuterium incorporated within different compounds. On average, the exchange parameters retrodict the exchange level with ~ 2.2-fold greater accuracy than treating all exchangeable hydrogens equally. The parameters can be used to produce hypothetical isotopic distributions that agree (± 16% RMSD) with experimental measurements. These initial studies are discussed in light of their potential value for identifying challenging metabolite species.
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Affiliation(s)
- Sandra N Majuta
- C. Eugene Bennett Department of Chemistry, West Virginia University, Morgantown, WV, 26506, USA
| | - Chong Li
- C. Eugene Bennett Department of Chemistry, West Virginia University, Morgantown, WV, 26506, USA
| | - Kinkini Jayasundara
- C. Eugene Bennett Department of Chemistry, West Virginia University, Morgantown, WV, 26506, USA
| | - Ahmad Kiani Karanji
- C. Eugene Bennett Department of Chemistry, West Virginia University, Morgantown, WV, 26506, USA
| | - Kushani Attanayake
- C. Eugene Bennett Department of Chemistry, West Virginia University, Morgantown, WV, 26506, USA
| | - Nandhini Ranganathan
- C. Eugene Bennett Department of Chemistry, West Virginia University, Morgantown, WV, 26506, USA
| | - Peng Li
- C. Eugene Bennett Department of Chemistry, West Virginia University, Morgantown, WV, 26506, USA
| | - Stephen J Valentine
- C. Eugene Bennett Department of Chemistry, West Virginia University, Morgantown, WV, 26506, USA.
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36
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Poltash ML, Shirzadeh M, McCabe JW, Moghadamchargari Z, Laganowsky A, Russell DH. New insights into the metal-induced oxidative degradation pathways of transthyretin. Chem Commun (Camb) 2019; 55:4091-4094. [PMID: 30887985 DOI: 10.1039/c9cc00682f] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The amyloidogenic mechanism of transthyretin is still debated but understanding it fully could lend insight into disease progression and potential therapeutics. Transthyretin was investigated revealing a metal-induced (Cr/Cu) oxidation pathway leading to N-terminal backbone fragmentation and oligomer formation; previously hidden details were revealed only by FT-IM-Orbitrap MS and surface-induced dissociation.
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Affiliation(s)
- Michael L Poltash
- Department of Chemistry, Texas A&M University, College Station, Texas 77843, USA.
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37
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Sahota N, AbuSalim DI, Wang ML, Brown CJ, Zhang Z, El-Baba TJ, Cook SP, Clemmer DE. A microdroplet-accelerated Biginelli reaction: mechanisms and separation of isomers using IMS-MS. Chem Sci 2019; 10:4822-4827. [PMID: 31160956 PMCID: PMC6509997 DOI: 10.1039/c9sc00704k] [Citation(s) in RCA: 45] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2019] [Accepted: 03/28/2019] [Indexed: 01/17/2023] Open
Abstract
Electrospray ionization (ESI) combined with ion mobility spectrometry (IMS) and mass spectrometry (MS) techniques is used to examine the Biginelli reaction in an ensemble of ions generated from droplets.
Electrospray ionization (ESI) combined with ion mobility spectrometry (IMS) and mass spectrometry (MS) techniques is used to examine the Biginelli reaction in an ensemble of ions generated from droplets. We find evidence for rapid dihydropyrimidinone formation from condensation of ethyl acetoacetate, benzaldehyde, and urea on the very short timescales associated with the electrospray process (∼10 μs to ∼1.0 ms). Control bulk-solution reactions show no product formation even after several days. This implies that the in-droplet reaction rate is enhanced by an astonishing factor. Examination of the reaction conditions and characterization of the intermediates en route to product shows evidence for variations in the reaction mechanism. IMS separation shows that the Knoevenagel condensation intermediate from benzaldehyde and ethyl acetoacetate exists as both the cis- and trans-isomer, in a ∼5 to 1 ratio. We suggest that the dramatic acceleration arises because of increased reagent confinement as electrosprayed droplets shrink. The ability of IMS-MS to resolve intermediates (including isomers) provides a new means of understanding reaction pathways.
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Affiliation(s)
- Navneet Sahota
- Department of Chemistry , Indiana University , 800 East Kirkwood Avenue , Bloomington , IN 47405-7102 , USA . ;
| | - Deyaa I AbuSalim
- Department of Chemistry , Indiana University , 800 East Kirkwood Avenue , Bloomington , IN 47405-7102 , USA . ;
| | - Melinda L Wang
- Department of Chemistry , Indiana University , 800 East Kirkwood Avenue , Bloomington , IN 47405-7102 , USA . ;
| | - Christopher J Brown
- Department of Chemistry , Indiana University , 800 East Kirkwood Avenue , Bloomington , IN 47405-7102 , USA . ;
| | - Zhicaho Zhang
- Department of Chemistry , Indiana University , 800 East Kirkwood Avenue , Bloomington , IN 47405-7102 , USA . ;
| | - Tarick J El-Baba
- Department of Chemistry , Indiana University , 800 East Kirkwood Avenue , Bloomington , IN 47405-7102 , USA . ;
| | - Silas P Cook
- Department of Chemistry , Indiana University , 800 East Kirkwood Avenue , Bloomington , IN 47405-7102 , USA . ;
| | - David E Clemmer
- Department of Chemistry , Indiana University , 800 East Kirkwood Avenue , Bloomington , IN 47405-7102 , USA . ;
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38
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Xia Z, Williams ER. Effect of droplet lifetime on where ions are formed in electrospray ionization. Analyst 2019; 144:237-248. [DOI: 10.1039/c8an01824c] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
The location of gaseous ion formation in electrospray ionization under native mass spectrometry conditions was investigated using theta emitters with tip diameters between 317 nm and 4.4 μm to produce droplets with lifetimes between 1 and 50 μs.
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Affiliation(s)
- Zijie Xia
- Department of Chemistry
- University of California
- Berkeley
- USA
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39
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Sundberg BN, Lagalante AF. Coaxial Electrospray Ionization for the Study of Rapid In-source Chemistry. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2018; 29:2023-2029. [PMID: 29949060 DOI: 10.1007/s13361-018-2004-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/14/2017] [Revised: 05/25/2018] [Accepted: 05/31/2018] [Indexed: 06/08/2023]
Abstract
Coaxial electrospray has been used effectively for several dual-emitter applications, but has not been utilized for the study of rapid in-source chemistry. In this paper, we report the fabrication of a coaxial, micro-volume dual-emitter through the modification of a manufacturer's standard electrospray probe. This modification creates rapid mixing inside the Taylor cone and the ability to manipulate fast reactions using a variety of solvents and analytes. We demonstrate its potential as a low-cost, dual-emitter assembly for diverse applications through three examples: relative ionization in a biphasic electrospray, hydrogen-deuterium exchange, and protein supercharging. Graphical Abstract.
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Affiliation(s)
- Brynn N Sundberg
- Department of Chemistry, Villanova University, 800 Lancaster Avenue, Villanova, PA, 19085, USA
| | - Anthony F Lagalante
- Department of Chemistry, Villanova University, 800 Lancaster Avenue, Villanova, PA, 19085, USA.
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40
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Zheng Q, Tian Y, Ruan X, Chen H, Wu X, Xu X, Wang G, Hao H, Ye H. Probing specific ligand-protein interactions by native-denatured exchange mass spectrometry. Anal Chim Acta 2018; 1036:58-65. [PMID: 30253837 DOI: 10.1016/j.aca.2018.07.072] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2018] [Revised: 07/21/2018] [Accepted: 07/27/2018] [Indexed: 10/28/2022]
Abstract
Probing ligand-target protein interactions provides essential information for deep understanding of biochemical machinery and design of drug screening assays. Native electrospray ionization-mass spectrometry (ESI-MS) is promising for direct analysis of ligand-protein complexes. However, it lacks the ability to distinguish between specific and non-specific ligand-protein interactions, and to further recognize the specifically bound proteins as drug target candidates, which remains as a major challenge in the field of drug developments by far. Herein we report a native-denatured exchange (NDX) mass spectrometry (MS) acquisition approach using a liquid sample-desorption electrospray ionization (LS-DESI) setup, and demonstrate its capability in enabling a change from native detection of noncovalent ligand-protein complexes to denatured analysis using three model ligand-protein complexes including myoglobin, CDP-ribonuclease and N,N',N″-triacetylchitotriose (NAG3)-lysozyme. Notably, we found the NDX-MS approach can readily discriminate specific ligand-protein interactions from nonspecific ones, as revealed by their distinct dynamic profiles of Kd as a function of the DESI spraying flow rate. Consequently, this NDX-MS approach holds promise for future applications to discovering specific protein targets for ligands of interest, and to screening compounds with high specificity to drug targets and thus eliminates off-target effects.
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Affiliation(s)
- Qiuling Zheng
- Department of Pharmaceutical Analysis, State Key Laboratory of Natural Medicines, China Pharmaceutical University, Tongjiaxiang #24, Nanjing, Jiangsu, 210009, China
| | - Yang Tian
- Key Laboratory of Drug Metabolism and Pharmacokinetics, State Key Laboratory of Natural Medicines, China Pharmaceutical University, Tongjiaxiang #24, Nanjing, Jiangsu, 210009, China
| | - Xujun Ruan
- Key Laboratory of Drug Metabolism and Pharmacokinetics, State Key Laboratory of Natural Medicines, China Pharmaceutical University, Tongjiaxiang #24, Nanjing, Jiangsu, 210009, China
| | - Hao Chen
- Center for Intelligent Chemical Instrumentation, Department of Chemistry and Biochemistry, Edison Biotechnology Institute, Ohio University, Athens, OH, 45701, United States
| | - Xunxun Wu
- Key Laboratory of Drug Metabolism and Pharmacokinetics, State Key Laboratory of Natural Medicines, China Pharmaceutical University, Tongjiaxiang #24, Nanjing, Jiangsu, 210009, China
| | - Xiaowei Xu
- Key Laboratory of Drug Metabolism and Pharmacokinetics, State Key Laboratory of Natural Medicines, China Pharmaceutical University, Tongjiaxiang #24, Nanjing, Jiangsu, 210009, China
| | - Guangji Wang
- Key Laboratory of Drug Metabolism and Pharmacokinetics, State Key Laboratory of Natural Medicines, China Pharmaceutical University, Tongjiaxiang #24, Nanjing, Jiangsu, 210009, China
| | - Haiping Hao
- Key Laboratory of Drug Metabolism and Pharmacokinetics, State Key Laboratory of Natural Medicines, China Pharmaceutical University, Tongjiaxiang #24, Nanjing, Jiangsu, 210009, China.
| | - Hui Ye
- Key Laboratory of Drug Metabolism and Pharmacokinetics, State Key Laboratory of Natural Medicines, China Pharmaceutical University, Tongjiaxiang #24, Nanjing, Jiangsu, 210009, China.
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41
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Li H, Vertes A. Solvent gradient electrospray for laser ablation electrospray ionization mass spectrometry. Analyst 2018; 142:2921-2927. [PMID: 28718844 DOI: 10.1039/c7an00819h] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Most electrospray based ambient ionization techniques, e.g., laser ablation electrospray ionization (LAESI), utilize a fixed spray solution composition. Complex samples often contain compounds of different polarity that exhibit a wide range of solubilities in the electrospray solvent. Thus, the fixed spray solution composition limits the molecular coverage of these approaches. Two-barrel theta glass capillaries have been used for the rapid mixing of two solutions for manipulating fast reactions including protein folding, unfolding, and charge state distributions. Here, we present a new variant of LAESI mass spectrometry (MS) by scanning the high voltages applied to the two barrels of a theta glass capillary containing two different solvents. In the resulting gradient LAESI (g-LAESI), the composition of the spray solution is ramped between the two solvents in the barrels to facilitate the detection of compounds of diverse polarity and solubility. Dynamic ranges and limits of detection achieved for g-LAESI-MS were comparable to conventional LAESI-MS. We have demonstrated simultaneous detection of different types of chemical standards, and polar and less polar compounds from Escherichia coli cell pellets using g-LAESI-MS. Varying the spray solution composition in a gradient electrospray can benefit from the enhanced solubilities of different analytes in polar and less polar solvents, ultimately improving the molecular coverage in the direct analysis of biological samples.
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Affiliation(s)
- Hang Li
- Department of Chemistry, W. M. Keck Institute for Proteomics Technology and Applications, The George Washington University, Washington, DC 20052, USA.
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42
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Banerjee S, Gnanamani E, Yan X, Zare RN. Can all bulk-phase reactions be accelerated in microdroplets? Analyst 2018; 142:1399-1402. [PMID: 28332662 DOI: 10.1039/c6an02225a] [Citation(s) in RCA: 113] [Impact Index Per Article: 18.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Recent studies have shown that microdroplet reactions are markedly accelerated compared to the corresponding bulk-phase reactions. This raises the question whether all reactions can be sped up by this means. We present a counter example, and we show that the reaction mechanism in microdroplets can differ sharply from that in bulk, especially because of the distinct microdroplet surface environment. This analysis helps to guide us how to choose and control reactions in microdroplets and provides a possible perspective on utilizing microdroplet chemistry to scale up synthesis.
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Affiliation(s)
- Shibdas Banerjee
- Department of Chemistry, Stanford University, Stanford, CA 94305, USA.
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Lai YH, Sathyamoorthi S, Bain RM, Zare RN. Microdroplets Accelerate Ring Opening of Epoxides. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2018; 29:1036-1043. [PMID: 29569167 DOI: 10.1007/s13361-018-1908-z] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/29/2017] [Revised: 01/18/2018] [Accepted: 01/29/2018] [Indexed: 06/08/2023]
Abstract
The nucleophilic opening of an epoxide is a classic organic reaction that has widespread utility in both academic and industrial applications. We have studied the reaction of limonene oxide with morpholine to form 1-methyl-2-morpholino-4-(prop-1-en-2-yl) cyclohexan-1-ol in bulk solution and in electrosprayed microdroplets with a 1:1 v/v water/methanol solvent system. We find that even after 90 min at room temperature, there is no product detected by nuclear magnetic resonance spectroscopy in bulk solution whereas in room-temperature microdroplets (2-3 μm in diameter), the yield is already 0.5% in a flight time of 1 ms as observed by mass spectrometry. This constitutes a rate acceleration of ~ 105 in the microdroplet environment, if we assume that as much as 5% of product is formed in bulk after 90 min of reaction time. We examine how the reaction rate depends on droplet size, solvent composition, sheath gas pressure, and applied voltage. These factors profoundly influence the extent of reaction. This dramatic acceleration is not limited to just one system. We have also found that the nucleophilic opening of cis-stilbene oxide by morpholine is similarly accelerated. Such large acceleration factors in reaction rates suggest the use of microdroplets for ring opening of epoxides in other systems, which may have practical significance if such a procedure could be scaled. Graphical Abstract This graphical image is distorted. It is too extended in the vertical direction. Please fix.ᅟ.
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Affiliation(s)
- Yin-Hung Lai
- Department of Chemistry, Stanford University, Stanford, CA, 94305, USA
| | | | - Ryan M Bain
- Department of Chemistry, Stanford University, Stanford, CA, 94305, USA
| | - Richard N Zare
- Department of Chemistry, Stanford University, Stanford, CA, 94305, USA.
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Wang H, Yong G, Brown SL, Lee HE, Zenaidee MA, Supuran CT, Donald WA. Supercharging protein ions in native mass spectrometry using theta capillary nanoelectrospray ionization mass spectrometry and cyclic alkylcarbonates. Anal Chim Acta 2018; 1003:1-9. [DOI: 10.1016/j.aca.2017.11.075] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2017] [Revised: 11/22/2017] [Accepted: 11/25/2017] [Indexed: 12/27/2022]
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Mortensen DN, Williams ER. Microsecond and nanosecond polyproline II helix formation in aqueous nanodrops measured by mass spectrometry. Chem Commun (Camb) 2018; 52:12218-12221. [PMID: 27711437 DOI: 10.1039/c6cc06423j] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The 1.5 μs and <400 ns time constants for the formation of polyproline II helix structures in 21 and 16 residue peptides, respectively, are measured using rapid mixing from theta-glass emitters coupled with mass spectrometry. Results from these studies should serve as useful benchmarks for comparison with computational simulation results.
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Affiliation(s)
- Daniel N Mortensen
- Department of Chemistry, University of California, Berkeley, California 94720-1460, USA.
| | - Evan R Williams
- Department of Chemistry, University of California, Berkeley, California 94720-1460, USA.
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46
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Multi-channel microfluidic chip coupling with mass spectrometry for simultaneous electro-sprays and extraction. Sci Rep 2017; 7:17389. [PMID: 29234133 PMCID: PMC5727197 DOI: 10.1038/s41598-017-17764-6] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2017] [Accepted: 11/30/2017] [Indexed: 02/07/2023] Open
Abstract
Considering the advantages and research status of microfluidic chip coupling with mass spectrometry (MS), a microfluidic chip-based multi-channel ionization (MCMCI) for the extraction of untreated compounds in complex matrices without sample pretreatments was developed. Quantitative analysis of human urine spiked with various rhodamine B concentrations was also performed, and good linearity was obtained. Comparing to the macro ionization device, MCMCI significantly improved the integration of ionization source, simplified the operation of such a device, and greatly increased the signal intensity with much lower gas pressure. Comparison of our MCMCI with two and three gas channels indicated that the liquid–liquid extraction process before spraying and after spraying produced similar MS results. Moreover, this MCMCI with three gas channels also implemented simultaneous dual sprays with high DC voltages, the interference of two samples was minor and ion suppression effect was drastically alleviated. Such advantages may easily enable internal calibration for accurate mass measurement. Furthermore, dual extraction can be implemented by integrating such multi-spray configuration, which can improve the extracted signal intensity and sensitivity. These technologies open up new avenues for the application of microfluidic chip coupling with MS.
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Jacobs MI, Davies JF, Lee L, Davis RD, Houle F, Wilson KR. Exploring Chemistry in Microcompartments Using Guided Droplet Collisions in a Branched Quadrupole Trap Coupled to a Single Droplet, Paper Spray Mass Spectrometer. Anal Chem 2017; 89:12511-12519. [PMID: 29048875 DOI: 10.1021/acs.analchem.7b03704] [Citation(s) in RCA: 47] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Recent studies suggest that reactions in aqueous microcompartments can occur at significantly different rates than those in the bulk. Most studies have used electrospray to generate a polydisperse source of highly charged microdroplets, leading to multiple confounding factors potentially influencing reaction rates (e.g., evaporation, charge, and size). Thus, the underlying mechanism for the observed enhancement remains unclear. We present a new type of electrodynamic balance-the branched quadrupole trap (BQT)-which can be used to study reactions in microdroplets in a controlled environment. The BQT allows for condensed phase chemical reactions to be initiated by colliding droplets with different reactants and levitating the merged droplet indefinitely. The performance of the BQT is characterized in several ways. Sub-millisecond mixing times as fast as ∼400 μs are measured for low velocity (∼0.1 m/s) collisions of droplets with <40 μm diameters. The reaction of o-phthalaldehyde (OPA) with alanine in the presence of dithiolthreitol is measured using both fluorescence spectroscopy and single droplet paper spray mass spectrometry. The bimolecular rate constant for reaction of alanine with OPA is found to be 84 ± 10 and 67 ± 6 M-1 s-1 in a 30 μm radius droplet and bulk solution, respectively, which demonstrates that bimolecular reaction rate coefficients can be quantified using merged microdroplets and that merged droplets can be used to study rate enhancements due to compartmentalization. Products of the reaction of OPA with alanine are detected in single droplets using paper spray mass spectrometry. We demonstrate that single droplets with <100 pg of analyte can easily be studied using single droplet mass spectrometry.
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Affiliation(s)
- Michael I Jacobs
- Department of Chemistry, University of California , Berkeley, California 94720, United States.,Chemical Sciences Division, Lawrence Berkeley National Laboratory , Berkeley, California 94720, United States
| | - James F Davies
- Chemical Sciences Division, Lawrence Berkeley National Laboratory , Berkeley, California 94720, United States
| | - Lance Lee
- Chemical Sciences Division, Lawrence Berkeley National Laboratory , Berkeley, California 94720, United States
| | - Ryan D Davis
- Chemical Sciences Division, Lawrence Berkeley National Laboratory , Berkeley, California 94720, United States
| | - Frances Houle
- Chemical Sciences Division, Lawrence Berkeley National Laboratory , Berkeley, California 94720, United States
| | - Kevin R Wilson
- Chemical Sciences Division, Lawrence Berkeley National Laboratory , Berkeley, California 94720, United States
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48
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Bain RM, Sathyamoorthi S, Zare RN. “On‐Droplet” Chemistry: The Cycloaddition of Diethyl Azodicarboxylate and Quadricyclane. Angew Chem Int Ed Engl 2017. [DOI: 10.1002/ange.201708413] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Affiliation(s)
- Ryan M. Bain
- Department of Chemistry Stanford University Stanford CA 94305 USA
| | | | - Richard N. Zare
- Department of Chemistry Stanford University Stanford CA 94305 USA
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Bain RM, Sathyamoorthi S, Zare RN. “On‐Droplet” Chemistry: The Cycloaddition of Diethyl Azodicarboxylate and Quadricyclane. Angew Chem Int Ed Engl 2017; 56:15083-15087. [DOI: 10.1002/anie.201708413] [Citation(s) in RCA: 50] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2017] [Revised: 08/19/2017] [Indexed: 11/09/2022]
Affiliation(s)
- Ryan M. Bain
- Department of Chemistry Stanford University Stanford CA 94305 USA
| | | | - Richard N. Zare
- Department of Chemistry Stanford University Stanford CA 94305 USA
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50
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Zhao F, Matt SM, Bu J, Rehrauer OG, Ben-Amotz D, McLuckey SA. Joule Heating and Thermal Denaturation of Proteins in Nano-ESI Theta Tips. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2017; 28:2001-2010. [PMID: 28699064 PMCID: PMC5693742 DOI: 10.1007/s13361-017-1732-x] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/15/2017] [Revised: 05/29/2017] [Accepted: 06/01/2017] [Indexed: 05/21/2023]
Abstract
Electro-osmotically induced Joule heating in theta tips and its effect on protein denaturation were investigated. Myoglobin, equine cytochrome c, bovine cytochrome c, and carbonic anhydrase II solutions were subjected to electro-osmosis in a theta tip and all of the proteins were denatured during the process. The extent of protein denaturation was found to increase with the applied square wave voltage and electrolyte concentration. The solution temperature at the end of a theta tip was measured directly by Raman spectroscopy and shown to increase with the square wave voltage, thereby demonstrating the effect of Joule heating through an independent method. The electro-osmosis of a solution comprised of myoglobin, bovine cytochrome c, and ubiquitin demonstrated that the magnitude of Joule heating that causes protein denaturation is positively correlated with protein melting temperature. This allows for a quick determination of a protein's relative thermal stability. This work establishes a fast, novel method for protein conformation manipulation prior to MS analysis and provides a temperature-controllable platform for the study of processes that take place in solution with direct coupling to mass spectrometry. Graphical Abstract ᅟ.
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Affiliation(s)
- Feifei Zhao
- Department of Chemistry, Purdue University, 560 Oval Drive, West Lafayette, IN, 47907-2084, USA
| | - Sarah M Matt
- Department of Chemistry, Purdue University, 560 Oval Drive, West Lafayette, IN, 47907-2084, USA
| | - Jiexun Bu
- Department of Chemistry, Purdue University, 560 Oval Drive, West Lafayette, IN, 47907-2084, USA
| | - Owen G Rehrauer
- Department of Chemistry, Purdue University, 560 Oval Drive, West Lafayette, IN, 47907-2084, USA
| | - Dor Ben-Amotz
- Department of Chemistry, Purdue University, 560 Oval Drive, West Lafayette, IN, 47907-2084, USA
| | - Scott A McLuckey
- Department of Chemistry, Purdue University, 560 Oval Drive, West Lafayette, IN, 47907-2084, USA.
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