1
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Sanders JD, Owen ON, Tran BH, Juetten KJ, Marty MT. UniChromCD for Demultiplexing Time-Resolved Charge Detection-Mass Spectrometry Data. Anal Chem 2024. [PMID: 39225436 DOI: 10.1021/acs.analchem.4c03250] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/04/2024]
Abstract
Charge detection mass spectrometry (CD-MS) enables characterization of large, heterogeneous analytes through the analysis of individual ion signals. Because hundreds to thousands of scans must be acquired to produce adequate ion statistics, CD-MS generally requires long analysis times. The slow acquisition speed of CD-MS complicates efforts to couple it with time-dispersive techniques, such as chromatography and ion mobility, because it is not always possible to acquire enough scans from a single sample injection to generate sufficient ion statistics. Multiplexing methods based on Hadamard and Fourier transforms offer an attractive solution to this problem by improving the duty cycle of the separation while preserving retention/drift time information. However, integrating multiplexing with CD-MS data processing is complex. Here, we present UniChromCD, a new module in the open-source UniDec package that incorporates CD-MS time-domain data processing with demultiplexing tools. Following a detailed description of the algorithm, we demonstrate its capabilities using two multiplexed CD-MS workflows: Hadamard-transform size-exclusion chromatography and Fourier-transform ion mobility. Overall, UniChromCD provides a user-friendly interface for analysis and visualization of time-resolved CD-MS data.
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Affiliation(s)
- James D Sanders
- Department of Chemistry and Biochemistry, University of Arizona, Tucson, Arizona 85721, United States
| | - October N Owen
- Department of Chemistry and Biochemistry, University of Arizona, Tucson, Arizona 85721, United States
| | - Brian H Tran
- Department of Chemistry and Biochemistry, University of Arizona, Tucson, Arizona 85721, United States
| | - Kyle J Juetten
- Department of Chemistry, The University of Texas at Austin, Austin, Texas 78712, United States
| | - Michael T Marty
- Department of Chemistry and Biochemistry, University of Arizona, Tucson, Arizona 85721, United States
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2
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Lutomski CA, El-Baba TJ, Clemmer DE, Jarrold MF. Thermal Remodeling of Human HDL Particles Reveals Diverse Subspecies. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2024; 35:2002-2007. [PMID: 39051481 PMCID: PMC11311237 DOI: 10.1021/jasms.4c00228] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/29/2024] [Revised: 07/14/2024] [Accepted: 07/16/2024] [Indexed: 07/27/2024]
Abstract
High-density lipoproteins (HDL) are micelle-like particles consisting of a core of triglycerides and cholesteryl esters surrounded by a shell of phospholipid, cholesterol, and apolipoproteins. HDL is considered "good" cholesterol, and its concentration in plasma is used clinically in assessing cardiovascular health. However, these particles vary in structure, composition, and therefore function, and thus can be resolved into subpopulations, some of which have specific cardioprotective properties. Mass measurements of HDL by charge detection mass spectrometry (CD-MS) previously revealed seven distinct subpopulations which could be delineated by mass and charge [Lutomski, C. A. et al. Anal. Chem. 2018]. Here, we investigate the thermal stabilities of these subpopulations; upon heating, the particles within each subpopulation undergo structural rearrangements with distinct transition temperatures. In addition, we find evidence for many new families of structures within each subpopulation; at least 15 subspecies of HDL are resolved. These subspecies vary in size, charge, and thermal stability. While this suggests that these new subspecies have unique molecular compositions, we cannot rule out the possibility that we have found evidence for new structural forms within the known subpopulations. The ability to resolve new subspecies of HDL particles may be important in understanding and delineating the role of unique particles in cardiovascular health and disease.
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Affiliation(s)
- Corinne A. Lutomski
- Department
of Chemistry, Indiana University, 800 E. Kirkwood Ave., Bloomington, Indiana 47405, United States
| | - Tarick J. El-Baba
- Department
of Chemistry, Indiana University, 800 E. Kirkwood Ave., Bloomington, Indiana 47405, United States
| | - David E. Clemmer
- Department
of Chemistry, Indiana University, 800 E. Kirkwood Ave., Bloomington, Indiana 47405, United States
| | - Martin F. Jarrold
- Department
of Chemistry, Indiana University, 800 E. Kirkwood Ave., Bloomington, Indiana 47405, United States
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3
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McPartlan MS, Harper CC, Hanozin E, Williams ER. Ion emission from 1-10 MDa salt clusters: individual charge state resolution with charge detection mass spectrometry. Analyst 2024; 149:735-744. [PMID: 38189568 DOI: 10.1039/d3an01913f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2024]
Abstract
Salt cluster ions produced by electrospray ionization are used for mass calibration and fundamental investigations into cluster stability and charge separation processes. However, previous studies have been limited to relatively small clusters owing to the heterogeneity associated with large, multiply-charged clusters that leads to unresolved signals in conventional m/z spectra. Here, charge detection mass spectrometry is used to measure both the mass and charge distributions of positively charged clusters of KCl, CaCl2, and LaCl3 with masses between ∼1 and 10 MDa by dynamically measuring the energy per charge, m/z, charge, and mass of simultaneously trapped individual ions throughout a 1 s trapping time. The extent of remaining hydration on the clusters, determined from the change in the frequency of ion motion with time as a result of residual water loss, follows the order KCl < CaCl2 < LaCl3, and is significantly lower than that of a pure water nanodrop, consistent with tighter water binding to the more highly charged cations in these clusters. The number of ion emission events from these clusters also follows this same trend, indicating that water at the cluster surface facilitates charge loss. A new frequency-based method to determine the magnitude of the charge loss resulting from individual ion emission events clearly resolves losses of +1 and +2 ions. Achieving this individual charge state resolution for ion emission events is an important advance in obtaining information about the late stages of bare gaseous ions formation. Future experiments on more hydrated clusters are expected to lead to a better understanding of ion formation in electrospray ionization.
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Affiliation(s)
- Matthew S McPartlan
- Department of Chemistry, University of California, Berkeley, California, 94720-1460, USA.
| | - Conner C Harper
- Department of Chemistry, University of California, Berkeley, California, 94720-1460, USA.
| | - Emeline Hanozin
- 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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4
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Harper CC, Miller ZM, Williams ER. Combined Multiharmonic Frequency Analysis for Improved Dynamic Energy Measurements and Accuracy in Charge Detection Mass Spectrometry. Anal Chem 2023; 95:16659-16667. [PMID: 37917546 DOI: 10.1021/acs.analchem.3c03160] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2023]
Abstract
The ability to determine ion energies in electrostatic ion-trap-based charge detection mass spectrometry (CDMS) experiments is important for the accurate measurement of individual ion m/z, charge, and mass. Dynamic energy measurements throughout the time an ion is trapped take advantage of the relationship between ion energy and the harmonic amplitude ratio (HAR) composed from the fundamental and second harmonic amplitudes in the Fourier transform of the ion signal. This method eliminates the need for energy-filtering optics in CDMS and makes it possible to measure energy lost in collisions and changes in ion masses due to dissociation. However, the accuracy of the energy measurement depends on the signal-to-noise ratio (S/N) of the amplitudes used to determine the HAR. Here, a major improvement to this HAR-based dynamic energy measurement method is achieved using HARs composed of higher-order harmonics in addition to the fundamental and second harmonic to determine ion energies. This combined harmonic amplitude ratios for precision energy refinement (CHARPER) method is applied to the analysis of a 103 nm polystyrene nanoparticle ion (359.7 MDa, m/z = 308,300) and the energy resolution (3140) and effective mass resolution (730) achieved are the best yet demonstrated in electrostatic ion-trap-based CDMS. The CHARPER method applied to an ensemble of several thousand adeno-associated virus ion signals also results in higher mass resolution compared to the basic HAR method, making it possible to resolve additional features in the composite mass histogram.
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Affiliation(s)
- Conner C Harper
- Department of Chemistry, University of California, Berkeley, California 94720-1460, United States
| | - Zachary M Miller
- Department of Chemistry, University of California, Berkeley, California 94720-1460, United States
| | - Evan R Williams
- Department of Chemistry, University of California, Berkeley, California 94720-1460, United States
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5
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Hanozin E, Harper CC, McPartlan MS, Williams ER. Dynamics of Rayleigh Fission Processes in ∼100 nm Charged Aqueous Nanodrops. ACS CENTRAL SCIENCE 2023; 9:1611-1622. [PMID: 37637724 PMCID: PMC10451037 DOI: 10.1021/acscentsci.3c00323] [Citation(s) in RCA: 13] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/16/2023] [Indexed: 08/29/2023]
Abstract
Fission of micron-size charged droplets has been observed using optical methods, but little is known about fission dynamics and breakup of smaller nanosize droplets that are important in a variety of natural and industrial processes. Here, spontaneous fission of individual aqueous nanodrops formed by electrospray is investigated using charge detection mass spectrometry. Fission processes ranging from formation of just two progeny droplets in 2 ms to production of dozens of progeny droplets over 100+ ms are observed for nanodrops that are charged above the Rayleigh limit. These results indicate that Rayleigh fission is a continuum of processes that produce progeny droplets that vary widely in charge, mass, and number.
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Affiliation(s)
- Emeline Hanozin
- Department of Chemistry, University of California, Berkeley, California 94720, United States
| | - Conner C. Harper
- Department of Chemistry, University of California, Berkeley, California 94720, United States
| | - Matthew S. McPartlan
- 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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6
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Botamanenko DY, Reitenbach DW, Miller LM, Jarrold MF. Electrostatic Linear Ion Trap Optimization Strategy for High Resolution Charge Detection Mass Spectrometry. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2023; 34:1731-1740. [PMID: 37466262 PMCID: PMC10842736 DOI: 10.1021/jasms.3c00177] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/20/2023]
Abstract
Single ion mass measurements allow mass distributions to be recorded for heterogeneous samples that cannot be analyzed by conventional mass spectrometry. In charge detection mass spectrometry (CD-MS), ions are detected using a conducting cylinder coupled to a charge sensitive amplifier. For optimum performance, the detection cylinder is embedded in an electrostatic linear ion trap (ELIT) where trapped ions oscillate between end-caps that act as opposing ion mirrors. The oscillating ions generate a periodic signal that is analyzed by fast Fourier transforms. The frequency yields the m/z, and the magnitude provides the charge. With a charge precision of 0.2 elementary charges, ions can be assigned to their correct charge states with a low error rate, and the m/z resolving power determines the mass resolving power. Previously, the best mass resolving power achieved with CD-MS was 300. We have recently increased the mass resolving power to 700, through the better optimization of the end-cap potentials. To make a more dramatic improvement in the m/z resolving power, it is necessary to find an ELIT geometry and end-cap potentials that can simultaneously make the ion oscillation frequency independent of both the ion energy and ion trajectory (angular divergence and radial offset) of the entering ion. We describe an optimization strategy that allows these conditions to be met while also adjusting the signal duty cycle to 50% to maximize the signal-to-noise ratio for the charge measurement. The optimized ELIT provides an m/z resolving power of over 300 000 in simulations. Coupled with the high precision charge determination available with CD-MS, this will yield a mass resolving power of 300 000. Such a high mass resolving power will be transformative for the analysis of heterogeneous samples.
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Affiliation(s)
- Daniel Y Botamanenko
- Chemistry Department, Indiana University, 800 E. Kirkwood Avenue, Bloomington, Indiana 47405
- Megadalton Solutions Inc., 3750 E Bluebird Lane, Bloomington, Indiana 47401
| | - David W Reitenbach
- Chemistry Department, Indiana University, 800 E. Kirkwood Avenue, Bloomington, Indiana 47405
| | - Lohra M Miller
- Chemistry Department, Indiana University, 800 E. Kirkwood Avenue, Bloomington, Indiana 47405
| | - Martin F Jarrold
- Chemistry Department, Indiana University, 800 E. Kirkwood Avenue, Bloomington, Indiana 47405
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7
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Harper CC, Avadhani VS, Hanozin E, Miller ZM, Williams ER. Dynamic Energy Measurements in Charge Detection Mass Spectrometry Eliminate Adverse Effects of Ion-Ion Interactions. Anal Chem 2023; 95:10077-10086. [PMID: 37343124 PMCID: PMC10389283 DOI: 10.1021/acs.analchem.3c01520] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/23/2023]
Abstract
Ion-ion interactions in charge detection mass spectrometers that use electrostatic traps to measure masses of individual ions have not been reported previously, although ion trajectory simulations have shown that these types of interactions affect ion energies and thereby degrade measurement performance. Here, examples of interactions between simultaneously trapped ions that have masses ranging from ca. 2 to 350 MDa and ca. 100 to 1000 charges are studied in detail using a dynamic measurement method that makes it possible to track the evolution of the mass, charge, and energy of individual ions over their trapping lifetimes. Signals from ions that have similar oscillation frequencies can have overlapping spectral leakage artifacts that result in slightly increased uncertainties in the mass determination, but these effects can be mitigated by the careful choice of parameters used in the short-time Fourier transform analysis. Energy transfers between physically interacting ions are also observed and quantified with individual ion energy measurement resolution as high as ∼950. The mass and charge of interacting ions do not change, and their corresponding measurement uncertainties are equivalent to ions that do not undergo physical interactions. Simultaneous trapping of multiple ions in CDMS can greatly decrease the acquisition time necessary to accumulate a statistically meaningful number of individual ion measurements. These results demonstrate that while ion-ion interactions can occur when multiple ions are trapped, they have negligible effects on mass accuracy when using the dynamic measurement method.
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Affiliation(s)
- Conner C. Harper
- Department of Chemistry, University of California, Berkeley, California, 94720-1460, United States
| | - Veena S. Avadhani
- Department of Chemistry, University of California, Berkeley, California, 94720-1460, United States
| | - Emeline Hanozin
- Department of Chemistry, University of California, Berkeley, California, 94720-1460, United States
| | - Zachary M. Miller
- Department of Chemistry, University of California, Berkeley, California, 94720-1460, United States
| | - Evan R. Williams
- Department of Chemistry, University of California, Berkeley, California, 94720-1460, United States
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8
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Mietzsch M, Liu W, Ma K, Bennett A, Nelson AR, Gliwa K, Chipman P, Fu X, Bechler S, McKenna R, Viner R. Production and characterization of an AAV1-VP3-only capsid: An analytical benchmark standard. Mol Ther Methods Clin Dev 2023; 29:460-472. [PMID: 37273903 PMCID: PMC10238842 DOI: 10.1016/j.omtm.2023.05.002] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2023] [Accepted: 05/04/2023] [Indexed: 06/06/2023]
Abstract
Adeno-associated viruses (AAVs) are non-enveloped ssDNA icosahedral T = 1 viruses used as vectors for clinical gene delivery. Currently, there are over 200 AAV-related clinical trials and six approved biologics on the market. As such new analytical methods are continually being developed to characterize and monitor the quality and purity of manufactured AAV vectors, these include ion-exchange chromatography and Direct Mass Technology. However, these methods require homogeneous analytical standards with a high molecular weight standard comparable to the mass of an AAV capsid. Described here is the design, production, purification, characterization, and the cryo-electron microscopy structure of an AAV1-VP3-only capsid that fulfills this need as a calibrant to determine capsid mass, charge, homogeneity, and transgene packaging characteristics.
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Affiliation(s)
- Mario Mietzsch
- Department of Biochemistry and Molecular Biology, College of Medicine, University of Florida, Gainesville, FL 32610, USA
| | - Weijing Liu
- Thermo Fisher Scientific, 355 River Oaks Parkway, San Jose, CA 95134, USA
| | - Ke Ma
- Thermo Fisher Scientific, 490 Lakeside Dr., Sunnyvale, CA 94085, USA
| | - Antonette Bennett
- Department of Biochemistry and Molecular Biology, College of Medicine, University of Florida, Gainesville, FL 32610, USA
| | - Austin R. Nelson
- Department of Biochemistry and Molecular Biology, College of Medicine, University of Florida, Gainesville, FL 32610, USA
| | - Keely Gliwa
- Department of Biochemistry and Molecular Biology, College of Medicine, University of Florida, Gainesville, FL 32610, USA
| | - Paul Chipman
- Department of Biochemistry and Molecular Biology, College of Medicine, University of Florida, Gainesville, FL 32610, USA
| | - Xiaofeng Fu
- Biological Science Imaging Resource, Department of Biological Sciences, Florida State University, Tallahassee, FL, USA
| | - Shane Bechler
- Thermo Fisher Scientific, 490 Lakeside Dr., Sunnyvale, CA 94085, USA
| | - Robert McKenna
- Department of Biochemistry and Molecular Biology, College of Medicine, University of Florida, Gainesville, FL 32610, USA
| | - Rosa Viner
- Thermo Fisher Scientific, 355 River Oaks Parkway, San Jose, CA 95134, USA
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9
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James VK, Sanders JD, Aizikov K, Fort KL, Grinfeld D, Makarov A, Brodbelt JS. Expanding Orbitrap Collision Cross-Section Measurements to Native Protein Applications Through Kinetic Energy and Signal Decay Analysis. Anal Chem 2023; 95:7656-7664. [PMID: 37133913 DOI: 10.1021/acs.analchem.3c00594] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
The measurement of collision cross sections (CCS, σ) offers supplemental information about sizes and conformations of ions beyond mass analysis alone. We have previously shown that CCSs can be determined directly from the time-domain transient decay of ions in an Orbitrap mass analyzer as ions oscillate around the central electrode and collide with neutral gas, thus removing them from the ion packet. Herein, we develop the modified hard collision model, thus deviating from the prior FT-MS hard sphere model, to determine CCSs as a function of center-of-mass collision energy in the Orbitrap analyzer. With this model, we aim to increase the upper mass limit of CCS measurement for native-like proteins, characterized by low charge states and presumed to be in more compact conformations. We also combine CCS measurements with collision induced unfolding and tandem mass spectrometry experiments to monitor protein unfolding and disassembly of protein complexes and measure CCSs of ejected monomers from protein complexes.
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Affiliation(s)
- Virginia K James
- Department of Chemistry, The University of Texas at Austin, Austin, Texas 78712, United States
| | - James D Sanders
- Department of Chemistry, The University of Texas at Austin, Austin, Texas 78712, United States
| | | | - Kyle L Fort
- Thermo Fisher Scientific, Bremen 28199, Germany
| | | | - Alexander Makarov
- Thermo Fisher Scientific, Bremen 28199, Germany
- Biomolecular Mass Spectrometry and Proteomics, Bijvoet Center for Biomolecular Research and Utrecht Institute for Pharmaceutical Sciences, University of Utrecht, Utrecht 3584, The Netherlands
| | - Jennifer S Brodbelt
- Department of Chemistry, The University of Texas at Austin, Austin, Texas 78712, United States
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10
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Harper CC, Miller ZM, McPartlan MS, Jordan JS, Pedder RE, Williams ER. Accurate Sizing of Nanoparticles Using a High-Throughput Charge Detection Mass Spectrometer without Energy Selection. ACS NANO 2023; 17:7765-7774. [PMID: 37027782 PMCID: PMC10389270 DOI: 10.1021/acsnano.3c00539] [Citation(s) in RCA: 14] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/19/2023]
Abstract
The sizes and shapes of nanoparticles play a critical role in their chemical and material properties. Common sizing methods based on light scattering or mobility lack individual particle specificity, and microscopy-based methods often require cumbersome sample preparation and image analysis. A promising alternative method for the rapid and accurate characterization of nanoparticle size is charge detection mass spectrometry (CDMS), an emerging technique that measures the masses of individual ions. A recently constructed CDMS instrument designed specifically for high acquisition speed, efficiency, and accuracy is described. This instrument does not rely on an ion energy filter or estimates of ion energy that have been previously required for mass determination, but instead uses direct, in situ measurements. A standardized sample of ∼100 nm diameter polystyrene nanoparticles and ∼50 nm polystyrene nanoparticles with amine-functionalized surfaces are characterized using CDMS and transmission electron microscopy (TEM). Individual nanoparticle masses measured by CDMS are transformed to diameters, and these size distributions are in close agreement with distributions measured by TEM. CDMS analysis also reveals dimerization of ∼100 nm nanoparticles in solution that cannot be determined by TEM due to the tendency of nanoparticles to agglomerate when dried onto a surface. Comparing the acquisition and analysis times of CDMS and TEM shows particle sizing rates up to ∼80× faster are possible using CDMS, even when samples ∼50× more dilute were used. The combination of both high-accuracy individual nanoparticle measurements and fast acquisition rates by CDMS represents an important advance in nanoparticle analysis capabilities.
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Affiliation(s)
- Conner C Harper
- Department of Chemistry, University of California, Berkeley, California 94720-1460, United States
| | - Zachary M Miller
- Department of Chemistry, University of California, Berkeley, California 94720-1460, United States
| | - Matthew S McPartlan
- Department of Chemistry, University of California, Berkeley, California 94720-1460, United States
| | - Jacob S Jordan
- Department of Chemistry, University of California, Berkeley, California 94720-1460, United States
| | - Randall E Pedder
- Ardara Technologies LP, Ardara, Pennsylvania 15615, United States
| | - Evan R Williams
- Department of Chemistry, University of California, Berkeley, California 94720-1460, United States
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11
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James VK, Sanders JD, Aizikov K, Fort KL, Grinfeld D, Makarov A, Brodbelt JS. Advancing Orbitrap Measurements of Collision Cross Sections to Multiple Species for Broad Applications. Anal Chem 2022; 94:15613-15620. [DOI: 10.1021/acs.analchem.2c02146] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Virginia K. James
- Department of Chemistry, The University of Texas at Austin, Austin, Texas 78712, United States
| | - James D. Sanders
- Department of Chemistry, The University of Texas at Austin, Austin, Texas 78712, United States
| | | | | | | | - Alexander Makarov
- Thermo Fisher Scientific, Bremen 28199, Germany
- Biomolecular Mass Spectrometry and Proteomics, Bijvoet Center for Biomolecular Research and Utrecht Institute for Pharmaceutical Sciences, University of Utrecht, Utrecht 3584, The Netherlands
| | - Jennifer S. Brodbelt
- Department of Chemistry, The University of Texas at Austin, Austin, Texas 78712, United States
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12
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Miller ZM, Harper CC, Lee H, Bischoff AJ, Francis MB, Schaffer DV, Williams ER. Apodization Specific Fitting for Improved Resolution, Charge Measurement, and Data Analysis Speed in Charge Detection Mass Spectrometry. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2022; 33:2129-2137. [PMID: 36173188 PMCID: PMC10389282 DOI: 10.1021/jasms.2c00213] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
Short-time Fourier transforms with short segment lengths are typically used to analyze single ion charge detection mass spectrometry (CDMS) data either to overcome effects of frequency shifts that may occur during the trapping period or to more precisely determine the time at which an ion changes mass or charge, or enters an unstable orbit. The short segment lengths can lead to scalloping loss unless a large number of zero-fills are used, making computational time a significant factor in real-time analysis of data. Apodization specific fitting leads to a 9-fold reduction in computation time compared to zero-filling to a similar extent of accuracy. This makes possible real-time data analysis using a standard desktop computer. Rectangular apodization leads to higher resolution than the more commonly used Gaussian or Hann apodization and makes it possible to separate ions with similar frequencies, a significant advantage for experiments in which the masses of many individual ions are measured simultaneously. Equally important is a >20% increase in S/N obtained with rectangular apodization compared to Gaussian or Hann, which directly translates to a corresponding improvement in accuracy of both charge measurements and ion energy measurements that rely on the amplitudes of the fundamental and harmonic frequencies. Combined with computing the fast Fourier transform in a lower-level language, this fitting procedure eliminates computational barriers and should enable real-time processing of CDMS data on a laptop computer.
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Affiliation(s)
- Zachary M. Miller
- College of Chemistry, University of California, Berkeley, California, 94720-1460, United States
| | - Conner C. Harper
- College of Chemistry, University of California, Berkeley, California, 94720-1460, United States
| | - Hyuncheol Lee
- College of Chemistry, University of California, Berkeley, California, 94720-1460, United States
- California Institute for Quantitative Biosciences, University of California, Berkeley, California 94720-1460, United States
| | - Amanda J. Bischoff
- College of Chemistry, University of California, Berkeley, California, 94720-1460, United States
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratories, Berkeley, California 94720, United States
| | - Matthew B. Francis
- College of Chemistry, University of California, Berkeley, California, 94720-1460, United States
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratories, Berkeley, California 94720, United States
| | - David V. Schaffer
- College of Chemistry, University of California, Berkeley, California, 94720-1460, United States
| | - Evan R. Williams
- College of Chemistry, University of California, Berkeley, California, 94720-1460, United States
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13
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Fremdling P, Esser TK, Saha B, Makarov AA, Fort KL, Reinhardt-Szyba M, Gault J, Rauschenbach S. A Preparative Mass Spectrometer to Deposit Intact Large Native Protein Complexes. ACS NANO 2022; 16:14443-14455. [PMID: 36037396 PMCID: PMC9527803 DOI: 10.1021/acsnano.2c04831] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/17/2022] [Accepted: 08/12/2022] [Indexed: 06/15/2023]
Abstract
Electrospray ion-beam deposition (ES-IBD) is a versatile tool to study the structure and reactivity of molecules from small metal clusters to large protein assemblies. It brings molecules gently into the gas phase, where they can be accurately manipulated and purified, followed by controlled deposition onto various substrates. In combination with imaging techniques, direct structural information on well-defined molecules can be obtained, which is essential to test and interpret results from indirect mass spectrometry techniques. To date, ion-beam deposition experiments are limited to a small number of custom instruments worldwide, and there are no commercial alternatives. Here we present a module that adds ion-beam deposition capabilities to a popular commercial MS platform (Thermo Scientific Q Exactive UHMR mass spectrometer). This combination significantly reduces the overhead associated with custom instruments, while benefiting from established high performance and reliability. We present current performance characteristics including beam intensity, landing-energy control, and deposition spot size for a broad range of molecules. In combination with atomic force microscopy (AFM) and transmission electron microscopy (TEM), we distinguish near-native from unfolded proteins and show retention of the native shape of protein assemblies after dehydration and deposition. Further, we use an enzymatic assay to quantify the activity of a noncovalent protein complex after deposition on a dry surface. Together, these results not only indicate a great potential of ES-IBD for applications in structural biology, but also outline the challenges that need to be solved for it to reach its full potential.
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Affiliation(s)
- Paul Fremdling
- Chemistry
Research Laboratory, Department of Chemistry, University of Oxford, 12 Mansfield Road, Oxford OX1 3TA, United Kingdom
| | - Tim K. Esser
- Chemistry
Research Laboratory, Department of Chemistry, University of Oxford, 12 Mansfield Road, Oxford OX1 3TA, United Kingdom
| | - Bodhisattwa Saha
- Chemistry
Research Laboratory, Department of Chemistry, University of Oxford, 12 Mansfield Road, Oxford OX1 3TA, United Kingdom
| | - Alexander A. Makarov
- Thermo
Fisher Scientific, Bremen 28199, Germany
- Biomolecular
Mass Spectrometry and Proteomics, Bijvoet Center for Biomolecular
Research and Utrecht Institute for Pharmaceutical Sciences, University of Utrecht, Padualaan 8, 3584
CH Utrecht, The Netherlands
| | | | | | - Joseph Gault
- Chemistry
Research Laboratory, Department of Chemistry, University of Oxford, 12 Mansfield Road, Oxford OX1 3TA, United Kingdom
| | - Stephan Rauschenbach
- Chemistry
Research Laboratory, Department of Chemistry, University of Oxford, 12 Mansfield Road, Oxford OX1 3TA, United Kingdom
- Max
Planck Institute for Solid State Research, Heisenbergstrasse 1, Stuttgart 70569, Germany
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14
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Harper CC, Miller ZM, Lee H, Bischoff AJ, Francis MB, Schaffer DV, Williams ER. Effects of Molecular Size on Resolution in Charge Detection Mass Spectrometry. Anal Chem 2022; 94:11703-11712. [PMID: 35961005 PMCID: PMC10389281 DOI: 10.1021/acs.analchem.2c02572] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Instrumental resolution of Fourier transform-charge detection mass spectrometry instruments with electrostatic ion trap detection of individual ions depends on the precision with which ion energy is determined. Energy can be selected using ion optic filters or from harmonic amplitude ratios (HARs) that provide Fellgett's advantage and eliminate the necessity of ion transmission loss to improve resolution. Unlike the ion energy-filtering method, the resolution of the HAR method increases with charge (improved S/N) and thus with mass. An analysis of the HAR method with current instrumentation indicates that higher resolution can be obtained with the HAR method than the best resolution demonstrated for instruments with energy-selective optics for ions in the low MDa range and above. However, this gain is typically unrealized because the resolution obtainable with molecular systems in this mass range is limited by sample heterogeneity. This phenomenon is illustrated with both tobacco mosaic virus (0.6-2.7 MDa) and AAV9 (3.7-4.7 MDa) samples where mass spectral resolution is limited by the sample, including salt adducts, and not by instrument resolution. Nevertheless, the ratio of full to empty AAV9 capsids and the included genome mass can be accurately obtained in a few minutes from 1× PBS buffer solution and an elution buffer containing 300+ mM nonvolatile content despite extensive adduction and lower resolution. Empty and full capsids adduct similarly indicating that salts encrust the complexes during late stages of droplet evaporation and that mass shifts can be calibrated in order to obtain accurate analyte masses even from highly salty solutions.
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Affiliation(s)
- Conner C. Harper
- College of Chemistry, University of California, Berkeley, California, 94720-1460
- California Institute for Quantitative Biosciences, University of California, Berkeley, California 94720-1460
| | - Zachary M. Miller
- College of Chemistry, University of California, Berkeley, California, 94720-1460
- California Institute for Quantitative Biosciences, University of California, Berkeley, California 94720-1460
| | - Hyuncheol Lee
- College of Chemistry, University of California, Berkeley, California, 94720-1460
- California Institute for Quantitative Biosciences, University of California, Berkeley, California 94720-1460
| | - Amanda J. Bischoff
- College of Chemistry, University of California, Berkeley, California, 94720-1460
- California Institute for Quantitative Biosciences, University of California, Berkeley, California 94720-1460
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratories, Berkeley, California 94720
| | - Matthew B. Francis
- College of Chemistry, University of California, Berkeley, California, 94720-1460
- California Institute for Quantitative Biosciences, University of California, Berkeley, California 94720-1460
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratories, Berkeley, California 94720
| | - David V. Schaffer
- College of Chemistry, University of California, Berkeley, California, 94720-1460
- California Institute for Quantitative Biosciences, University of California, Berkeley, California 94720-1460
| | - Evan R. Williams
- College of Chemistry, University of California, Berkeley, California, 94720-1460
- California Institute for Quantitative Biosciences, University of California, Berkeley, California 94720-1460
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15
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Brown BA, Guda PR, Zeng X, Anthony A, Couse A, Barnes LF, Sharon EM, Trinidad JC, Sen CK, Jarrold MF, Ghatak S, Clemmer DE. Analysis of Keratinocytic Exosomes from Diabetic and Nondiabetic Mice by Charge Detection Mass Spectrometry. Anal Chem 2022; 94:8909-8918. [PMID: 35699514 PMCID: PMC9450994 DOI: 10.1021/acs.analchem.2c00453] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Unresolved inflammation compromises diabetic wound healing. Recently, we reported that inadequate RNA packaging in murine wound-edge keratinocyte-originated exosomes (Exoκ) leads to persistent inflammation [Zhou, X. ACS Nano 2020, 14(10), 12732-12748]. Herein, we use charge detection mass spectrometry (CDMS) to analyze intact Exoκ isolated from a 5 day old wound-edge tissue of diabetic mice and a heterozygous nondiabetic littermate control group. In CDMS, the charge (z) and mass-to-charge ratio (m/z) of individual exosome particles are measured simultaneously, enabling the direct analysis of masses in the 1-200 MDa range anticipated for exosomes. These measurements reveal a broad mass range for Exoκ from ∼10 to >100 MDa. The m and z values for these exosomes appear to fall into families (subpopulations); a statistical modeling analysis partially resolves ∼10-20 Exoκ subpopulations. Complementary proteomics, immunofluorescence, and electron microscopy studies support the CDMS results that Exoκ from diabetic and nondiabetic mice vary substantially. Subpopulations having high z (>650) and high m (>44 MDa) are more abundant in nondiabetic animals. We propose that these high m and z particles may arise from differences in cargo packaging. The veracity of this idea is discussed in light of other recent CDMS results involving genome packaging in vaccines, as well as exosome imaging experiments. Characterization of intact exosome particles based on the physical properties of m and z provides a new means of investigating wound healing and suggests that CDMS may be useful for other pathologies.
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Affiliation(s)
- Brooke A Brown
- Department of Chemistry, Indiana University, Bloomington, Indiana 47505, United States
| | - Poornachander R Guda
- Indiana Center for Regenerative Medicine & Engineering, Department of Surgery, Indiana University School of Medicine, Indianapolis, Indiana 46202, United States
| | - Xuyao Zeng
- Department of Chemistry, Indiana University, Bloomington, Indiana 47505, United States
| | - Adam Anthony
- Department of Chemistry, Indiana University, Bloomington, Indiana 47505, United States
| | - Andrew Couse
- Department of Chemistry, Indiana University, Bloomington, Indiana 47505, United States
| | - Lauren F Barnes
- Department of Chemistry, Indiana University, Bloomington, Indiana 47505, United States
| | - Edie M Sharon
- Department of Chemistry, Indiana University, Bloomington, Indiana 47505, United States
| | - Jonathan C Trinidad
- Department of Chemistry, Indiana University, Bloomington, Indiana 47505, United States
| | - Chandan K Sen
- Indiana Center for Regenerative Medicine & Engineering, Department of Surgery, Indiana University School of Medicine, Indianapolis, Indiana 46202, United States
| | - Martin F Jarrold
- Department of Chemistry, Indiana University, Bloomington, Indiana 47505, United States
| | - Subhadip Ghatak
- Indiana Center for Regenerative Medicine & Engineering, Department of Surgery, Indiana University School of Medicine, Indianapolis, Indiana 46202, United States
| | - David E Clemmer
- Department of Chemistry, Indiana University, Bloomington, Indiana 47505, United States
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16
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Abstract
Native mass spectrometry (MS) is aimed at preserving and determining the native structure, composition, and stoichiometry of biomolecules and their complexes from solution after they are transferred into the gas phase. Major improvements in native MS instrumentation and experimental methods over the past few decades have led to a concomitant increase in the complexity and heterogeneity of samples that can be analyzed, including protein-ligand complexes, protein complexes with multiple coexisting stoichiometries, and membrane protein-lipid assemblies. Heterogeneous features of these biomolecular samples can be important for understanding structure and function. However, sample heterogeneity can make assignment of ion mass, charge, composition, and structure very challenging due to the overlap of tens or even hundreds of peaks in the mass spectrum. In this review, we cover data analysis, experimental, and instrumental advances and strategies aimed at solving this problem, with an in-depth discussion of theoretical and practical aspects of the use of available deconvolution algorithms and tools. We also reflect upon current challenges and provide a view of the future of this exciting field.
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Affiliation(s)
- Amber D. Rolland
- Department of Chemistry and Biochemistry, 1253 University of Oregon, Eugene, OR, USA 97403-1253
| | - James S. Prell
- Department of Chemistry and Biochemistry, 1253 University of Oregon, Eugene, OR, USA 97403-1253
- Materials Science Institute, 1252 University of Oregon, Eugene, OR, USA 97403-1252
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17
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Barnes LF, Draper BE, Jarrold MF. Analysis of Recombinant Adenovirus Vectors by Ion Trap Charge Detection Mass Spectrometry: Accurate Molecular Weight Measurements beyond 150 MDa. Anal Chem 2022; 94:1543-1551. [PMID: 35023731 DOI: 10.1021/acs.analchem.1c02439] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Adenovirus is one of the largest nonenveloped, double-stranded DNA viruses. It is widely used as a gene therapy vector and has recently received a lot of attention as a novel vaccine platform for SARS-CoV-2. Human adenovirus 5 (HAdV5) contains over 2500 protein molecules and has a 36 kbp genome. Adenovirus is well beyond the range of conventional mass spectrometry, and it was unclear how well such a large complex could be desolvated. Here, we report molecular weight (MW) distributions measured for HAdV5 and for 11 recombinant AdV vectors with genomes of varying lengths. The MW distributions were recorded using ion trap charge detection mass spectrometry (CDMS), a single-particle technique where m/z and charge are measured for individual ions. The results show that ions as large as 150 MDa can be effectively desolvated and accurate MW distributions obtained. The MW distribution for HAdV5 contains a narrow peak at 156.1 MDa, assigned to the infectious virus. A smaller peak at 129.6 MDa is attributed to incomplete particles that have not packaged a genome. The ions in the 129.6 MDa peak have a much lower average charge than those in the peak at 156.1 MDa. This is attributed to the empty particles missing some or all of the fibers that decorate the surface of the virion. The MW measured for the mature virus (156.1 MDa) is much larger than that predicted from sequence masses and copy numbers of the constituents (142.5 MDa). Measurements performed for recombinant AdV as a function of genome length show that for every 1 MDa increase in the genome MW, the MW of the mature virus increases by around 2.3 MDa. The additional 1.3 MDa is attributed to core proteins that are copackaged with the DNA. This observation suggests that the discrepancy between the measured and expected MWs for mature HAdV5 is due to an underestimate in the copy numbers of the core proteins.
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Affiliation(s)
- Lauren F Barnes
- Chemistry Department, Indiana University, 800 E Kirkwood Avenue, Bloomington, Indiana 47405, United States
| | - Benjamin E Draper
- Megadalton Solutions, Inc., 3750 E Bluebird Lane, Bloomington, Indiana 47401, United States
| | - Martin F Jarrold
- Chemistry Department, Indiana University, 800 E Kirkwood Avenue, Bloomington, Indiana 47405, United States
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18
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Pope BL, Joaquin D, Hickey JT, Mismash N, Heravi T, Shrestha J, Arslanian AJ, Mortensen DN, Dearden DV. Multi-CRAFTI: Relative Collision Cross Sections from Fourier Transform Ion Cyclotron Resonance Mass Spectrometric Line Width Measurements. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2022; 33:131-140. [PMID: 34928604 DOI: 10.1021/jasms.1c00297] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Determination of collision cross sections (CCS) using the cross-sectional areas by the Fourier transform ion cyclotron resonance (CRAFTI) technique is limited by the requirement that accurate pressures in the trapping cell of the mass spectrometer must be known. Experiments must also be performed in the energetic hard-sphere regime such that ions decohere after single collisions with neutrals; this limits application to ions that are not much more massive than the neutrals. To mitigate these problems, we have resonantly excited two (or more) ions of different m/z to the same center-of-mass kinetic energy in a single experiment, subjecting them to identical neutral pressures. We term this approach "multi-CRAFTI". This facilitates measurement of relative CCS without requiring knowledge of the pressure and enables determination of absolute CCS using internal standards. Experiments with tetraalkylammonium ions yield CCS in reasonable agreement with the one-ion-at-a-time CRAFTI approach and with ion mobility spectrometry (IMS) when differences in collision energetics are taken into account (multi-CRAFTI generally yields smaller CCS than does IMS due to the higher collision energies employed in multi-CRAFTI). Comparison of multi-CRAFTI and IMS results with CCS calculated from structures computed at the M06-2X/6-31+G* level of theory using projection approximation or trajectory method values, respectively, indicates that the computed structures have CCS increasingly smaller than the experimental CCS as m/z increases, implying the computational model overestimates interactions between the alkyl arms. For ions that undergo similar collisional decoherence processes, relative CCS reach constant values at lower collision energies than do absolute CCS values, suggesting a means of increasing the accessible upper m/z limit by employing multi-CRAFTI.
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Affiliation(s)
- Brigham L Pope
- Department of Chemistry and Biochemistry, Brigham Young University, Provo, Utah 84602-1030, United States
| | - Daniel Joaquin
- Department of Chemistry and Biochemistry, Brigham Young University, Provo, Utah 84602-1030, United States
| | - Jacob T Hickey
- Department of Chemistry and Biochemistry, Brigham Young University, Provo, Utah 84602-1030, United States
| | - Noah Mismash
- Department of Chemistry and Biochemistry, Brigham Young University, Provo, Utah 84602-1030, United States
| | - Tina Heravi
- Department of Chemistry and Biochemistry, Brigham Young University, Provo, Utah 84602-1030, United States
| | - Jamir Shrestha
- Department of Chemistry and Biochemistry, Brigham Young University, Provo, Utah 84602-1030, United States
| | - Andrew J Arslanian
- Department of Chemistry and Biochemistry, Brigham Young University, Provo, Utah 84602-1030, United States
| | - Daniel N Mortensen
- Department of Chemistry and Biochemistry, Brigham Young University, Provo, Utah 84602-1030, United States
| | - David V Dearden
- Department of Chemistry and Biochemistry, Brigham Young University, Provo, Utah 84602-1030, United States
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19
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Gustafson EL, Murray HV, Caldwell T, Austin DE. Accurately Mapping Image Charge and Calibrating Ion Velocity in Charge Detection Mass Spectrometry. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2020; 31:2161-2170. [PMID: 32856905 DOI: 10.1021/jasms.0c00263] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Image charge detection is the foundation of charge detection mass spectrometry (CDMS). The mass-to-charge ratio, m/z, of a highly charged ion or particle is determined by measuring the particle's charge and velocity. Charge is typically determined from a calibrated image charge signal, and the particle velocity is calculated using the peaks from the shaped signal as they relate to the particle position and time-of-flight through a detector of known length. Although much has been done to improve the charge accuracy in CDMS, little has been done to address the inconsistencies in the particle velocity measurements and the interpretation of peak position and effective electrode length. In this work, we combine SIMION ion trajectory software and the Shockley-Ramo theorem to accurately determine the effective electrode length, peak position, and shape of the signal peaks. Six model charge detector geometries were examined with this method and evaluated in laboratory experiments. Experimental results in all cases agreed with the simulations. Using a charge detector with multiple, 12.7 mm-long cylindrical electrodes, experimental velocities across and between electrodes agreed within 0.25% relative standard deviation (RSD) when this method was used to correct for effective electrode lengths, corresponding to an uncertainty in the effective electrode length of only 40 μm. For a detector with multiple electrodes and varied electrode spacing, experiments showed that the peak amplitude and shape vary with the geometry and with the particle path through the detector, whereas all peak areas agreed to within 2.3% RSD. For a charge detector made of two printed circuit boards, the velocities agreed within 0.44% RSD using the calculated effective electrode length.
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Affiliation(s)
- Elaura L Gustafson
- Department of Chemistry and Biochemistry, Brigham Young University, Provo, Utah 84602, United States
| | - Halle V Murray
- Department of Chemistry and Biochemistry, Brigham Young University, Provo, Utah 84602, United States
| | - Tabitha Caldwell
- Department of Chemistry and Biochemistry, Brigham Young University, Provo, Utah 84602, United States
| | - Daniel E Austin
- Department of Chemistry and Biochemistry, Brigham Young University, Provo, Utah 84602, United States
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20
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Todd AR, Barnes LF, Young K, Zlotnick A, Jarrold MF. Higher Resolution Charge Detection Mass Spectrometry. Anal Chem 2020; 92:11357-11364. [PMID: 32806905 PMCID: PMC8587657 DOI: 10.1021/acs.analchem.0c02133] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Charge detection mass spectrometry is a single particle technique where the masses of individual ions are determined from simultaneous measurements of each ion's m/z ratio and charge. The ions pass through a conducting cylinder, and the charge induced on the cylinder is detected. The cylinder is usually placed inside an electrostatic linear ion trap so that the ions oscillate back and forth through the cylinder. The resulting time domain signal is analyzed by fast Fourier transformation; the oscillation frequency yields the m/z, and the charge is determined from the magnitudes. The mass resolving power depends on the uncertainties in both quantities. In previous work, the mass resolving power was modest, around 30-40. In this work we report around an order of magnitude improvement. The improvement was achieved by coupling high-accuracy charge measurements (obtained with dynamic calibration) with higher resolution m/z measurements. The performance was benchmarked by monitoring the assembly of the hepatitis B virus (HBV) capsid. The HBV capsid assembly reaction can result in a heterogeneous mixture of intermediates extending from the capsid protein dimer to the icosahedral T = 4 capsid with 120 dimers. Intermediates of all possible sizes were resolved, as well as some overgrown species. Despite the improved mass resolving power, the measured peak widths are still dominated by instrumental resolution. Heterogeneity makes only a small contribution. Resonances were observed in some of the m/z spectra. They result from ions with different masses and charges having similar m/z values. Analogous resonances are expected whenever the sample is a heterogeneous mixture assembled from a common building block.
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21
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Antoine R. Weighing synthetic polymers of ultra-high molar mass and polymeric nanomaterials: What can we learn from charge detection mass spectrometry? RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2020; 34 Suppl 2:e8539. [PMID: 31353622 DOI: 10.1002/rcm.8539] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/21/2019] [Revised: 07/19/2019] [Accepted: 07/19/2019] [Indexed: 06/10/2023]
Abstract
Advances in soft ionization techniques for mass spectrometry (MS) of polymeric materials make it possible to determine the masses of intact molecular ions exceeding megadaltons. Interfacing MS with separation and fragmentation methods has additionally led to impressive advances in the ability to structurally characterize polymers. Even if the gap to the megadalton range has been bridged by MS for polymers standards, the MS-based analysis for more complex polymeric materials is still challenging. Charge detection mass spectrometry (CDMS) is a single-molecule method where the mass and the charge of each ion are directly determined from individual measurements. The entire molecular mass distribution of a polymer sample can be thus accurately measured. Described in this perspective paper is how molecular weight distribution as well as charge distribution can provide new insights into the structural and compositional studies of synthetic polymers and polymeric nanomaterials in the megadalton to gigadalton range of molecular weight. The recent multidimensional CDMS studies involving couplings with separation and dissociation techniques will be presented. And, finally, an outlook for the future avenues of the CDMS technique in the field of synthetic polymers of ultra-high molar mass and polymeric nanomaterials will be provided.
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Affiliation(s)
- Rodolphe Antoine
- Univ Lyon, Université Claude Bernard Lyon 1, CNRS, Institut Lumière Matière, UMR 5306, F-69622, Lyon, France
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22
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Todd AR, Jarrold MF. Dynamic Calibration Enables High-Accuracy Charge Measurements on Individual Ions for Charge Detection Mass Spectrometry. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2020; 31:1241-1248. [PMID: 32353231 DOI: 10.1021/jasms.0c00081] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Charge detection mass spectrometry (CDMS) depends on the measurement of the charge induced on a cylinder by individual ions by means of a charge-sensitive amplifier. For high-accuracy charge measurements, the detection cylinder is embedded in an electrostatic linear ion trap (ELIT), and the ions oscillate back and forth through the cylinder so that multiple measurements are made. To assign the charge state with a low error rate, the charge of each ion must be determined with an uncertainty (root-mean-square deviation) of around 0.2 elementary charges. We show here that high-accuracy charge measurements can be achieved for large ions by dynamic calibration of the charge measurement using an internal standard. The internal standard is generated by irradiating the detection cylinder, by means of a small antenna, with a radiofrequency signal. Using this approach, we have obtained a relative charge uncertainty of around 5 × 10-4, allowing charge-state resolution to be achieved for single ions with up to 500 charges. In another application of this approach, the detection cylinder is irradiated with a signal that counteracts the transients generated when the potentials on the ELIT end-caps are switched to trapping mode. Using this approach, the dead time after switching (during which the signal cannot be analyzed) has been reduced by more than an order of magnitude. With charge-state resolution for ions with up to 500 charges, we were able to calibrate the charges precisely. The results show that the response of the charge-sensitive amplifier with dynamic calibration is linear to within a small fraction of an elementary charge.
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Affiliation(s)
- Aaron R Todd
- Chemistry Department, Indiana University, Bloomington, Indiana 47405 United States
| | - Martin F Jarrold
- Chemistry Department, Indiana University, Bloomington, Indiana 47405 United States
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23
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Kahana M, Musbat L, Nihamkin M, Diamant Y, Piperno S, Ytzhak S, Toker Y. Harmonic height distribution in pickup spectroscopy within electrostatic ion beam traps. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2020; 91:043301. [PMID: 32357746 DOI: 10.1063/1.5142358] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/12/2019] [Accepted: 03/16/2020] [Indexed: 06/11/2023]
Abstract
Pickup spectroscopy is a means of determining the abundance, mass, charge, and lifetime of ions oscillating in electrostatic ion beam traps. Here, we present a framework for describing the harmonic height distribution of the Fourier transform of the pickup signal and discuss the importance of the pickup positioning, bunch dynamics, and pickup width on the harmonic height distribution. We demonstrate the methodology using measurements from a newly constructed electrostatic ion beam trap.
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Affiliation(s)
- Michal Kahana
- Department of Physics and Institute of Nanotechnology and Advanced Materials, Bar-Ilan University, Ramat-Gan 5290002, Israel
| | - Lihi Musbat
- Department of Physics and Institute of Nanotechnology and Advanced Materials, Bar-Ilan University, Ramat-Gan 5290002, Israel
| | - Maria Nihamkin
- Department of Physics and Institute of Nanotechnology and Advanced Materials, Bar-Ilan University, Ramat-Gan 5290002, Israel
| | - Yael Diamant
- Department of Physics and Institute of Nanotechnology and Advanced Materials, Bar-Ilan University, Ramat-Gan 5290002, Israel
| | - Silvia Piperno
- Department of Physics and Institute of Nanotechnology and Advanced Materials, Bar-Ilan University, Ramat-Gan 5290002, Israel
| | - Shany Ytzhak
- Department of Physics and Institute of Nanotechnology and Advanced Materials, Bar-Ilan University, Ramat-Gan 5290002, Israel
| | - Yoni Toker
- Department of Physics and Institute of Nanotechnology and Advanced Materials, Bar-Ilan University, Ramat-Gan 5290002, Israel
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24
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Resolving heterogeneous macromolecular assemblies by Orbitrap-based single-particle charge detection mass spectrometry. Nat Methods 2020; 17:395-398. [DOI: 10.1038/s41592-020-0770-7] [Citation(s) in RCA: 72] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2019] [Accepted: 02/05/2020] [Indexed: 12/28/2022]
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25
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Bond KM, Lyktey NA, Tsvetkova IB, Dragnea B, Jarrold MF. Disassembly Intermediates of the Brome Mosaic Virus Identified by Charge Detection Mass Spectrometry. J Phys Chem B 2020; 124:2124-2131. [PMID: 32141748 DOI: 10.1021/acs.jpcb.0c00008] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Capsid disassembly and genome release are critical steps in the lifecycle of a virus. However, their mechanisms are poorly understood, both in vivo and in vitro. Here, we have identified two in vitro disassembly pathways of the brome mosaic virus (BMV) by charge detection mass spectrometry and transmission electron microscopy. When subjected to a pH jump to a basic environment at low ionic strength, protein-RNA interactions are disrupted. Under these conditions, BMV appears to disassemble mainly through a global cleavage event into two main fragments: a near complete capsid that has released the RNA and the released RNA complexed to a small number of the capsid proteins. Upon slow buffer exchange to remove divalent cations at neutral pH, capsid protein interactions are disrupted. The BMV virions swell but there is no measurable loss of the RNA. Some of the virions break into small fragments, leading to an increase in the abundance of species with masses less than 1 MDa. The peak attributed to the BMV virion shifts to a higher mass with time. The mass increase is attributed to additional capsid proteins associating with the disrupted capsid protein-RNA complex, where the RNA is presumably partially exposed. It is likely that this pathway is more closely related to how the capsid disassembles in vivo, as it offers the advantage of protecting the RNA with the capsid protein until translation begins.
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Affiliation(s)
- Kevin M Bond
- Chemistry Department, Indiana University, 800 E Kirkwood Avenue, Bloomington, Indiana 47405, United States
| | - Nicholas A Lyktey
- Chemistry Department, Indiana University, 800 E Kirkwood Avenue, Bloomington, Indiana 47405, United States
| | - Irina B Tsvetkova
- Chemistry Department, Indiana University, 800 E Kirkwood Avenue, Bloomington, Indiana 47405, United States
| | - Bogdan Dragnea
- Chemistry Department, Indiana University, 800 E Kirkwood Avenue, Bloomington, Indiana 47405, United States
| | - Martin F Jarrold
- Chemistry Department, Indiana University, 800 E Kirkwood Avenue, Bloomington, Indiana 47405, United States
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26
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Fan J, Lian P, Li M, Liu X, Zhou X, Ouyang Z. Ion Mobility Separation Using a Dual-LIT Miniature Mass Spectrometer. Anal Chem 2020; 92:2573-2579. [PMID: 31940171 DOI: 10.1021/acs.analchem.9b04271] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Ion mobility (IM) has been increasingly used in combination with mass spectrometry (MS) for chemical and biological analysis. While implementation of IM with MS usually requires complex instrumentation with delicate controls, in this study we explored the potential of performing IM separation using dual-linear ion traps (LITs) in a miniature mass spectrometer, which was originally developed for performing comprehensive MS/MS scan functions with a simple instrumentation configuration. The IM separation was achieved by ion transfer between the LITs with dynamic gas flow. Its performance was characterized for analysis of a broad range of chemical and biological compounds including small organic compounds such as trisaccharides, raffinose, cellotriose, and melezitose, as well as protein conformers. The demonstrated technique serves as another example of developing powerful hybrid instrument functions with simple configurations and miniaturized sizes.
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Affiliation(s)
- Jingjin Fan
- State Key Laboratory of Precision Measurement Technology and Instruments, Department of Precision Instrument , Tsinghua University , Beijing 100084 , China
| | - Penglong Lian
- State Key Laboratory of Precision Measurement Technology and Instruments, Department of Precision Instrument , Tsinghua University , Beijing 100084 , China
| | - Ming Li
- NCS Testing Technology Company, Limited , Beijing 100081 , China
| | - Xinwei Liu
- State Key Laboratory of Precision Measurement Technology and Instruments, Department of Precision Instrument , Tsinghua University , Beijing 100084 , China
| | - Xiaoyu Zhou
- State Key Laboratory of Precision Measurement Technology and Instruments, Department of Precision Instrument , Tsinghua University , Beijing 100084 , China
| | - Zheng Ouyang
- State Key Laboratory of Precision Measurement Technology and Instruments, Department of Precision Instrument , Tsinghua University , Beijing 100084 , China
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27
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Todd AR, Alexander AW, Jarrold MF. Implementation of a Charge-Sensitive Amplifier without a Feedback Resistor for Charge Detection Mass Spectrometry Reduces Noise and Enables Detection of Individual Ions Carrying a Single Charge. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2020; 31:146-154. [PMID: 32881508 DOI: 10.1021/jasms.9b00010] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Charge detection mass spectrometry (CDMS) depends on the measurement of the charge induced on a cylinder by individual ions by means of a charge-sensitive amplifier. Electrical noise limits the accuracy of the charge measurement and the smallest charge that can be detected. Thermal noise in the feedback resistor is a major source of electrical noise. We describe the implementation of a charge-sensitive amplifier without a feedback resistor. The design has significantly reduced 1/f noise facilitating the detection of high m/z ions and substantially reducing the measurement time required to achieve almost perfect charge accuracy. With the new design we have been able to detect individual ions carrying a single charge. This is an important milestone in the development of CDMS.
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Affiliation(s)
- Aaron R Todd
- Chemistry Department, Indiana University, Bloomington, Indiana 47405, United States
| | - Andrew W Alexander
- Chemistry Department, Indiana University, Bloomington, Indiana 47405, United States
| | - Martin F Jarrold
- Chemistry Department, Indiana University, Bloomington, Indiana 47405, United States
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28
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Harper CC, Williams ER. Enhanced Multiplexing in Fourier Transform Charge Detection Mass Spectrometry by Decoupling Ion Frequency from Mass to Charge Ratio. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2019; 30:2637-2645. [PMID: 31720975 DOI: 10.1007/s13361-019-02330-3] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/03/2019] [Revised: 08/27/2019] [Accepted: 08/28/2019] [Indexed: 06/10/2023]
Abstract
Weighing single ions with charge detection mass spectrometry (CDMS) makes it possible to obtain the masses of molecules of essentially unlimited size even in highly heterogeneous samples, but producing a mass histogram that is representative of all of the components in a mixture requires substantial measurement time. Multiple ions can be trapped to reduce analysis time but ion signals can overlap. To determine the maximum gains in analysis speed possible with current instrumentation with multiple ion trapping, simulations calculating the frequency and overlap rate of ions with different mass, charge, and energy ranges were performed. For an analyte with a broad mass distribution, such as long chain polyethylene glycol (PEG, 8 MDa), gains in analysis speed of up to 160 times that of prior CDMS experiments are possible. For signals from homogeneous samples, ions with the same m/z have frequencies that overlap and interfere, reducing the effectiveness of multiplexing in experiments where ions have the same energy per charge. We show that by maximizing the decoupling of ion m/z from frequency using a broad range of ion energies, the rate of signal overlap is significantly reduced making it possible to trap more ions. Under optimum decoupling conditions, a measurement speed nearly 50 times greater than that of prior CDMS experiments is possible for RuBisCO (517 kDa). The reduction in overlap due to decoupling also results in more accurate quantitation in samples that contain multiple analytes with different concentrations.
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Affiliation(s)
- Conner C Harper
- Department of Chemistry, University of California, Berkeley, CA, 94720-1460, USA
| | - Evan R Williams
- Department of Chemistry, University of California, Berkeley, CA, 94720-1460, USA.
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29
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Todd AR, Jarrold MF. Dramatic Improvement in Sensitivity with Pulsed Mode Charge Detection Mass Spectrometry. Anal Chem 2019; 91:14002-14008. [PMID: 31589418 PMCID: PMC6834878 DOI: 10.1021/acs.analchem.9b03586] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Charge detection mass spectrometry (CDMS) is emerging as a valuable tool to determine mass distributions for heterogeneous and high-mass samples. It is a single-particle technique where masses are determined for individual ions from simultaneous measurements of their mass-to-charge ratio (m/z) and charge. Ions are trapped in an electrostatic linear ion trap (ELIT) and oscillate back and forth through a detection cylinder. The trap is open and able to trap ions for a small fraction of the total measurement time so most of the ions (>99.8%) in a continuous ion beam are lost. Here, we implement an ion storage scheme where ions are accumulated and stored in a hexapole and then injected into the ELIT at the right time for them to be trapped. This pulsed mode of operation increases the sensitivity of CDMS by more than 2 orders of magnitude, which allows much lower titer samples to be analyzed. A limit of detection of 3.3 × 108 particles/mL was obtained for hepatitis B virus T = 4 capsids with a 1.3 μL sample. The hexapole where the ions are accumulated and stored is a significant distance from the ion trap so ions are dispersed in time by their m/z values as they travel between the hexapole and the ELIT. By varying the delay time between ion release and trapping, different windows of m/z values can be trapped.
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Affiliation(s)
- Aaron R. Todd
- Chemistry Department, Indiana University, 800 East Kirkwood Avenue, Bloomington, Indiana 47405, United States
| | - Martin F. Jarrold
- Chemistry Department, Indiana University, 800 East Kirkwood Avenue, Bloomington, Indiana 47405, United States
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30
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Xiong C, Liu H, Liu C, Xue J, Zhan L, Nie Z. Mass, Size, and Density Measurements of Microparticles in a Quadrupole Ion Trap. Anal Chem 2019; 91:13508-13513. [PMID: 31608618 DOI: 10.1021/acs.analchem.9b02574] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
The physical properties of microparticles, such as mass, size, and density, are critical for their functions. The comprehensive characterization of these physical parameters, however, remains a fundamental challenge. Here, we developed a particle mass spectrometry (PMS) methodology for determining the mass, size, and density of microparticles simultaneously. The collisional cross-section (CCS) and mass spectrometry (MS) measurements were performed in a single quadrupole ion trap (QIT), and the two modes can be switched easily by tuning the electric and gas hydrodynamic fields of the QIT. The feasibility of the method was demonstrated through a series of monodispersed polystyrene (PS) and silica (SiO2) particle standards. The SiO2/polypyrrole core-shell particles were also successfully characterized, and the measured results were verified by using conventional methods.
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Affiliation(s)
- Caiqiao Xiong
- 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
| | - Huihui Liu
- 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
| | - Chaozi Liu
- 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
| | - Jinjuan Xue
- 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
| | - Lingpeng Zhan
- 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
| | - 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
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31
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Kafader JO, Beu SC, Early BP, Melani RD, Durbin KR, Zabrouskov V, Makarov AA, Maze JT, Shinholt DL, Yip PF, Kelleher NL, Compton PD, Senko MW. STORI Plots Enable Accurate Tracking of Individual Ion Signals. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2019; 30:2200-2203. [PMID: 31512223 PMCID: PMC6852666 DOI: 10.1007/s13361-019-02309-0] [Citation(s) in RCA: 41] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/19/2019] [Revised: 07/30/2019] [Accepted: 08/02/2019] [Indexed: 05/08/2023]
Abstract
Charge detection mass spectrometry (CDMS) of low-level signals is currently limited to the analysis of individual ions that generate a persistent signal during the entire observation period. Ions that disintegrate during the observation period produce reduced frequency domain signal amplitudes, which lead to an underestimation of the ion charge state, and thus the ion mass. The charge assignment can only be corrected through an accurate determination of the time of ion disintegration. The traditional mechanisms for temporal signal analysis have severe limitations for temporal resolution, spectral resolution, and signal-to-noise ratios. Selective Temporal Overview of Resonant Ions (STORI) plots provide a new framework to accurately analyze low-level time domain signals of individual ions. STORI plots allow for complete correction of intermittent signals, the differentiation of single and multiple ions at the same frequency, and the association of signals that spontaneously change frequency.
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Affiliation(s)
- Jared O Kafader
- Departments of Chemistry and Molecular Biosciences, the Chemistry of Life Processes Institute, The Proteomics Center of Excellence at Northwestern University, Evanston, IL, 60208, USA
| | | | - Bryan P Early
- Departments of Chemistry and Molecular Biosciences, the Chemistry of Life Processes Institute, The Proteomics Center of Excellence at Northwestern University, Evanston, IL, 60208, USA
| | - Rafael D Melani
- Departments of Chemistry and Molecular Biosciences, the Chemistry of Life Processes Institute, The Proteomics Center of Excellence at Northwestern University, Evanston, IL, 60208, USA
| | - Kenneth R Durbin
- Departments of Chemistry and Molecular Biosciences, the Chemistry of Life Processes Institute, The Proteomics Center of Excellence at Northwestern University, Evanston, IL, 60208, USA
| | | | | | | | | | - Ping F Yip
- Thermo Fisher Scientific, San Jose, CA, 95134, USA
| | - Neil L Kelleher
- Departments of Chemistry and Molecular Biosciences, the Chemistry of Life Processes Institute, The Proteomics Center of Excellence at Northwestern University, Evanston, IL, 60208, USA
| | - Philip D Compton
- Departments of Chemistry and Molecular Biosciences, the Chemistry of Life Processes Institute, The Proteomics Center of Excellence at Northwestern University, Evanston, IL, 60208, USA
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32
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Haynes IW, Wu G, Haque MA, Li H, Do TD. Conformational Preference of Macrocycles Investigated by Ion-Mobility Mass Spectrometry and Distance Geometry Modeling. Anal Chem 2019; 91:13439-13447. [DOI: 10.1021/acs.analchem.9b02100] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Affiliation(s)
- Isaac W. Haynes
- Department of Chemistry, University of Tennessee, Knoxville, Tennessee 37996, United States
| | - Guangcheng Wu
- Department of Chemistry, Zhejiang University, Hangzhou 310027, China
| | - Md. Ashraful Haque
- Department of Chemistry, University of Tennessee, Knoxville, Tennessee 37996, United States
| | - Hao Li
- Department of Chemistry, Zhejiang University, Hangzhou 310027, China
| | - Thanh D. Do
- Department of Chemistry, University of Tennessee, Knoxville, Tennessee 37996, United States
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33
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Dunbar CA, Rayaprolu V, Wang JCY, Brown CJ, Leishman E, Jones-Burrage S, Trinidad JC, Bradshaw HB, Clemmer DE, Mukhopadhyay S, Jarrold MF. Dissecting the Components of Sindbis Virus from Arthropod and Vertebrate Hosts: Implications for Infectivity Differences. ACS Infect Dis 2019; 5:892-902. [PMID: 30986033 DOI: 10.1021/acsinfecdis.8b00356] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Sindbis virus (SINV) is an enveloped, single-stranded RNA virus, which is transmitted via mosquitos to a wide range of vertebrate hosts. SINV produced by vertebrate, baby hamster kidney (BHK) cells is more than an order of magnitude less infectious than SINV produced from mosquito (C6/36) cells. The cause of this difference is poorly understood. In this study, charge detection mass spectrometry was used to determine the masses of intact SINV particles isolated from BHK and C6/36 cells. The measured masses are substantially different: 52.88 MDa for BHK derived SINV and 50.69 MDa for C6/36 derived. Further analysis using several mass spectrometry-based methods and biophysical approaches indicates that BHK derived SINV has a substantially higher mass than C6/36 derived because in the lipid bilayer, there is a higher portion of lipids containing long chain fatty acids. The difference in lipid composition could influence the organization of the lipid bilayer. As a result, multiple stages of the viral lifecycle may be affected including assembly and budding, particle stability during transmission, and fusion events, all of which could contribute to the differences in infectivity.
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Affiliation(s)
- Carmen A. Dunbar
- Department of Chemistry, Indiana University, 800 East Kirkwood Avenue, Bloomington, Indiana 47405, United States
| | - Vamseedhar Rayaprolu
- Department of Biology, Indiana University, Jordan Hall, 1001 East Third Street, Bloomington, Indiana 47405, United States
| | - Joseph C.-Y. Wang
- Department of Molecular and Cellular Biochemistry, Indiana University, Simon Hall, 212 South Hawthorne Drive, Bloomington, Indiana 47405, United States
| | - Christopher J. Brown
- Department of Chemistry, Indiana University, 800 East Kirkwood Avenue, Bloomington, Indiana 47405, United States
| | - Emma Leishman
- Department of Psychological and Brain Sciences, Indiana University, 1101 East Tenth Street, Bloomington, Indiana 47405, United States
| | - Sara Jones-Burrage
- Department of Biology, Indiana University, Jordan Hall, 1001 East Third Street, Bloomington, Indiana 47405, United States
| | - Jonathan C. Trinidad
- Department of Chemistry, Indiana University, 800 East Kirkwood Avenue, Bloomington, Indiana 47405, United States
| | - Heather B. Bradshaw
- Department of Psychological and Brain Sciences, Indiana University, 1101 East Tenth Street, Bloomington, Indiana 47405, United States
| | - David E. Clemmer
- Department of Chemistry, Indiana University, 800 East Kirkwood Avenue, Bloomington, Indiana 47405, United States
| | - Suchetana Mukhopadhyay
- Department of Biology, Indiana University, Jordan Hall, 1001 East Third Street, Bloomington, Indiana 47405, United States
| | - Martin F. Jarrold
- Department of Chemistry, Indiana University, 800 East Kirkwood Avenue, Bloomington, Indiana 47405, United States
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34
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Elliott AG, Harper CC, Lin HW, Williams ER. Effects of Individual Ion Energies on Charge Measurements in Fourier Transform Charge Detection Mass Spectrometry (FT-CDMS). JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2019; 30:946-955. [PMID: 30430436 DOI: 10.1007/s13361-018-2094-8] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/15/2018] [Revised: 10/15/2018] [Accepted: 10/15/2018] [Indexed: 06/09/2023]
Abstract
A method to correct for the effect of ion energy on charge measurements of individual ions trapped and weighed with charge detection mass spectrometry (CDMS) is demonstrated. Ions with different energies induce different signal patterns inside an electrostatic ion trap. The sum of the amplitudes of the fundamental and second harmonic frequencies in the Fourier transform of the induced signal, which has been used to obtain the ion charge, depends on both ion energy and charge. The amplitudes of the fundamental frequencies of ions increase over time as ions lose energy by collisions with background gas and solvent loss from larger ions. Model ion signals are simulated with the same time-domain amplitude at different energies and frequencies and the resulting fundamental frequency amplitudes are used to normalize real ion signals for energy and frequency effects. The fundamental frequency amplitude decreases dramatically below 20 kHz and increases by ~ 17% from the highest energy to lowest energy that is stable with a given trap potential at all frequencies. Normalizing the fundamental frequency amplitude with the modeled amplitudes removes the systematic changes in the charge measurement of polyethylene glycol (PEG) and other ions and makes it possible to signal average the amplitude over long times, which reduces the charge uncertainty to 0.04% for a PEG ion for a 500-ms measurement. This method improves charge measurement accuracy and uncertainty, which are important for high-accuracy mass measurement with CDMS. Graphical abstract ᅟ.
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Affiliation(s)
- Andrew G Elliott
- Department of Chemistry, University of California, Berkeley, CA, 94720-1460, USA
| | - Conner C Harper
- Department of Chemistry, University of California, Berkeley, CA, 94720-1460, USA
| | - Haw-Wei Lin
- Department of Chemistry, University of California, Berkeley, CA, 94720-1460, USA
| | - Evan R Williams
- Department of Chemistry, University of California, Berkeley, CA, 94720-1460, USA.
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35
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Harper CC, Elliott AG, Oltrogge LM, Savage DF, Williams ER. Multiplexed Charge Detection Mass Spectrometry for High-Throughput Single Ion Analysis of Large Molecules. Anal Chem 2019; 91:7458-7465. [PMID: 31082222 DOI: 10.1021/acs.analchem.9b01669] [Citation(s) in RCA: 55] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Applications of charge detection mass spectrometry (CDMS) for measuring the masses of large molecules, macromolecular complexes, and synthetic polymers that are too large or heterogeneous for conventional mass spectrometry measurements are made possible by weighing individual ions in order to avoid interferences between ions. Here, a new multiplexing method that makes it possible to measure the masses of many ions simultaneously in CDMS is demonstrated. Ions with a broad range of kinetic energies are trapped. The energy of each ion is obtained from the ratio of the intensity of the fundamental to the second harmonic frequencies of the periodic trapping motion making it possible to measure both the m/ z and charge of each ion. Because ions with the exact same m/ z but with different energies appear at different frequencies, the probability of ion-ion interference is significantly reduced. We show that the measured mass of a protein complex consisting of 16 protomers, RuBisCO (517 kDa), is not affected by the number of trapped ions with up to 21 ions trapped simultaneously in these experiments. Ion-ion interactions do not affect the ion trapping lifetime up to 1 s, and there is no influence of the number of ions on the measured charge-state distribution of bovine serum albumin (66.5 kDa), indicating that ion-ion interactions do not adversely affect any of these measurements. Over an order of magnitude gain in measurement speed over single ion analysis is demonstrated, and significant additional gains are expected with this multi-ion measurement method.
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36
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Gabelica V, Shvartsburg AA, Afonso C, Barran P, Benesch JL, Bleiholder C, Bowers MT, Bilbao A, Bush MF, Campbell JL, Campuzano ID, Causon T, Clowers BH, Creaser CS, De Pauw E, Far J, Fernandez‐Lima F, Fjeldsted JC, Giles K, Groessl M, Hogan CJ, Hann S, Kim HI, Kurulugama RT, May JC, McLean JA, Pagel K, Richardson K, Ridgeway ME, Rosu F, Sobott F, Thalassinos K, Valentine SJ, Wyttenbach T. Recommendations for reporting ion mobility Mass Spectrometry measurements. MASS SPECTROMETRY REVIEWS 2019; 38:291-320. [PMID: 30707468 PMCID: PMC6618043 DOI: 10.1002/mas.21585] [Citation(s) in RCA: 288] [Impact Index Per Article: 57.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/25/2018] [Revised: 11/01/2018] [Accepted: 11/02/2018] [Indexed: 05/02/2023]
Abstract
Here we present a guide to ion mobility mass spectrometry experiments, which covers both linear and nonlinear methods: what is measured, how the measurements are done, and how to report the results, including the uncertainties of mobility and collision cross section values. The guide aims to clarify some possibly confusing concepts, and the reporting recommendations should help researchers, authors and reviewers to contribute comprehensive reports, so that the ion mobility data can be reused more confidently. Starting from the concept of the definition of the measurand, we emphasize that (i) mobility values (K0 ) depend intrinsically on ion structure, the nature of the bath gas, temperature, and E/N; (ii) ion mobility does not measure molecular surfaces directly, but collision cross section (CCS) values are derived from mobility values using a physical model; (iii) methods relying on calibration are empirical (and thus may provide method-dependent results) only if the gas nature, temperature or E/N cannot match those of the primary method. Our analysis highlights the urgency of a community effort toward establishing primary standards and reference materials for ion mobility, and provides recommendations to do so. © 2019 The Authors. Mass Spectrometry Reviews Published by Wiley Periodicals, Inc.
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Affiliation(s)
- Valérie Gabelica
- University of Bordeaux, INSERM and CNRS, ARNA Laboratory, IECB site2 rue Robert Escarpit, 33600PessacFrance
| | | | | | - Perdita Barran
- Michael Barber Centre for Collaborative Mass SpectrometryManchester Institute for Biotechnology, University of ManchesterManchesterUK
| | - Justin L.P. Benesch
- Department of Chemistry, Chemistry Research LaboratoryUniversity of Oxford, Mansfield Road, OX1 3TAOxfordUK
| | - Christian Bleiholder
- Department of Chemistry and BiochemistryFlorida State UniversityTallahasseeFlorida32311
| | | | - Aivett Bilbao
- Biological Sciences DivisionPacific Northwest National LaboratoryRichlandWashington
| | - Matthew F. Bush
- Department of ChemistryUniversity of WashingtonSeattleWashington
| | | | | | - Tim Causon
- University of Natural Resources and Life Sciences (BOKU)Department of Chemistry, Division of Analytical ChemistryViennaAustria
| | - Brian H. Clowers
- Department of ChemistryWashington State UniversityPullmanWashington
| | - Colin S. Creaser
- Centre for Analytical ScienceDepartment of Chemistry, Loughborough UniversityLoughboroughUK
| | - Edwin De Pauw
- Laboratoire de spectrométrie de masse (L.S.M.) − Molecular SystemsUniversité de LiègeLiègeBelgium
| | - Johann Far
- Laboratoire de spectrométrie de masse (L.S.M.) − Molecular SystemsUniversité de LiègeLiègeBelgium
| | | | | | | | - Michael Groessl
- Department of Nephrology and Hypertension and Department of BioMedical ResearchInselspital, Bern University Hospital, University of Bern, Switzerland and TofwerkThunSwitzerland
| | | | - Stephan Hann
- University of Natural Resources and Life Sciences (BOKU)Department of Chemistry, Division of Analytical ChemistryViennaAustria
| | - Hugh I. Kim
- Department of ChemistryKorea UniversitySeoulKorea
| | | | - Jody C. May
- Department of ChemistryCenter for Innovative Technology, Vanderbilt UniversityNashvilleTennessee
| | - John A. McLean
- Department of ChemistryCenter for Innovative Technology, Vanderbilt UniversityNashvilleTennessee
| | - Kevin Pagel
- Freie Universitaet BerlinInstitute for Chemistry and BiochemistryBerlinGermany
| | | | | | - Frédéric Rosu
- CNRS, INSERM and University of BordeauxInstitut Européen de Chimie et BiologiePessacFrance
| | - Frank Sobott
- Antwerp UniversityBiomolecular & Analytical Mass SpectrometryAntwerpBelgium
- Astbury Centre for Structural Molecular BiologyUniversity of LeedsLeedsUK
- School of Molecular and Cellular BiologyUniversity of LeedsLeedsUK
| | - Konstantinos Thalassinos
- Institute of Structural and Molecular Biology, Division of BiosciencesUniversity College LondonLondonWC1E 6BTUK
- United Kingdom and Institute of Structural and Molecular BiologyDepartment of Biological Sciences, Birkbeck College, University of LondonLondonWC1E 7HXUK
| | - Stephen J. Valentine
- C. Eugene Bennett Department of ChemistryWest Virginia UniversityMorgantownWest Virginia
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37
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Dunbar CA, Callaway HM, Parrish CR, Jarrold MF. Probing Antibody Binding to Canine Parvovirus with Charge Detection Mass Spectrometry. J Am Chem Soc 2018; 140:15701-15711. [PMID: 30398860 DOI: 10.1021/jacs.8b08050] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
There are many techniques for monitoring and measuring the interactions between proteins and ligands. Most of these techniques are ensemble methods that can provide association constants and in some cases stoichiometry. Here we use charge detection mass spectrometry (CDMS), a single particle technique, to probe the interactions of antigen binding fragments (Fabs) from a series of antibodies with the canine parvovirus (CPV) capsid. In addition to providing the average number of bound Fabs as a function of Fab concentration (i.e., the binding curve), CDMS measurements provide information about the distribution of bound Fabs. We show that the distribution of bound ligands is much better at distinguishing between different binding models than the binding curve. The binding of Fab E to CPV is a textbook example. A maximum of 60 Fabs bind and the results are consistent with a model where all sites have the same binding affinity. However, for Fabs B, F, and 14, the distributions can only be fit by a model where there are distinct virus subpopulations with different binding affinities. This behavior can be distinguished from a situation where all CPV particles are identical, and each particle has the same distribution of sites with different binding affinities. The different responses to viral heterogeneity can be traced to the Fab binding sites. A comparison of Fab binding to new and aged CPV capsids reveals that a post-translational modification at the binding site for Fab E (M569) probably reduces the binding affinity.
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Affiliation(s)
- Carmen A Dunbar
- Department of Chemistry , Indiana University , 800 E. Kirkwood Ave. , Bloomington , Indiana 47405 , United States
| | - Heather M Callaway
- Baker Institute for Animal Health, Department of Microbiology and Immunology, College of Veterinary Medicine , Cornell University , Ithaca , New York 14850 , United States
| | - Colin R Parrish
- Baker Institute for Animal Health, Department of Microbiology and Immunology, College of Veterinary Medicine , Cornell University , Ithaca , New York 14850 , United States
| | - Martin F Jarrold
- Department of Chemistry , Indiana University , 800 E. Kirkwood Ave. , Bloomington , Indiana 47405 , United States
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38
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Hogan JA, Jarrold MF. Optimized Electrostatic Linear Ion Trap for Charge Detection Mass Spectrometry. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2018; 29:2086-2095. [PMID: 29987663 DOI: 10.1007/s13361-018-2007-x] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/17/2018] [Revised: 05/25/2018] [Accepted: 05/29/2018] [Indexed: 06/08/2023]
Abstract
In charge detection mass spectrometry (CDMS), ions are passed through a detection tube and the m/z ratio and charge are determined for each ion. The uncertainty in the charge and m/z determinations can be dramatically reduced by embedding the detection tube in an electrostatic linear ion trap (ELIT) so that ions oscillate back and forth through the detection tube. The resulting time domain signal can be analyzed by fast Fourier transforms (FFTs). The ion's m/z is proportional to the square of the oscillation frequency, and its charge is derived from the FFT magnitude. The ion oscillation frequency is dependent on the physical dimensions of the trap as well as the ion energy. A new ELIT has been designed for CDMS using the central particle method. In the new design, the kinetic energy dependence of the ion oscillation frequency is reduced by an order of magnitude. An order of magnitude reduction in energy dependence should have led to an order of magnitude reduction in the uncertainty of the m/z determination. In practice, a factor of four improvements was achieved. This discrepancy is probably mainly due to the trajectory dependence of the ion oscillation frequency. The new ELIT design uses a duty cycle of 50%. We show that a 50% duty cycle produces the lowest uncertainty in the charge determination. This is due to the absence of even-numbered harmonics in the FFT, which in turn leads to an increase in the magnitude of the peak at the fundamental frequency. Graphical Abstract ᅟ.
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Affiliation(s)
- Joanna A Hogan
- Chemistry Department, Indiana University, Bloomington, IN, 47405, USA
| | - Martin F Jarrold
- Chemistry Department, Indiana University, Bloomington, IN, 47405, USA.
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39
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Harper CC, Elliott AG, Lin HW, Williams ER. Determining Energies and Cross Sections of Individual Ions Using Higher-Order Harmonics in Fourier Transform Charge Detection Mass Spectrometry (FT-CDMS). JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2018; 29:1861-1869. [PMID: 29860679 DOI: 10.1007/s13361-018-1987-x] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/24/2018] [Revised: 04/26/2018] [Accepted: 05/03/2018] [Indexed: 06/08/2023]
Abstract
A general method for in situ measurements of the energy of individual ions trapped and weighed using charge detection mass spectrometry (CDMS) is described. Highly charged (> 300 e), individual polyethylene glycol (PEG) ions are trapped and oscillate within an electrostatic trap, producing a time domain signal. A segmented Fourier transform (FT) of this signal yields the temporal evolution of the fundamental and harmonic frequencies of ion motion throughout the 500-ms trap time. The ratio of the fundamental frequency and second harmonic (HAR) depends on the ion energy, which is an essential parameter for measuring ion mass in CDMS. This relationship is calibrated using simulated ion signals, and the calibration is compared to the HAR values measured for PEG ion signals where the ion energy was also determined using an independent method that requires that the ions be highly charged (> 300 e). The mean error of 0.6% between the two measurements indicates that the HAR method is an accurate means of ion energy determination that does not depend on ion size or charge. The HAR is determined dynamically over the entire trapping period, making it possible to observe the change in ion energy that takes place as solvent evaporates from the ion and collisions with background gas occur. This method makes it possible to measure mass changes, either from solvent evaporation or from molecular fragmentation (MSn), as well as the cross sections of ions measured using CDMS. Graphical Abstract.
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Affiliation(s)
- Conner C Harper
- Department of Chemistry, University of California, Berkeley, CA, 94720-1460, USA
| | - Andrew G Elliott
- Department of Chemistry, University of California, Berkeley, CA, 94720-1460, USA
| | - Haw-Wei Lin
- Department of Chemistry, University of California, Berkeley, CA, 94720-1460, USA
| | - Evan R Williams
- Department of Chemistry, University of California, Berkeley, CA, 94720-1460, USA.
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40
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Lutomski CA, Gordon SM, Remaley AT, Jarrold MF. Resolution of Lipoprotein Subclasses by Charge Detection Mass Spectrometry. Anal Chem 2018; 90:6353-6356. [DOI: 10.1021/acs.analchem.8b01127] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Affiliation(s)
- Corinne A. Lutomski
- Department of Chemistry, Indiana University, Bloomington, Indiana 47405, United States
| | - Scott M. Gordon
- Lipoprotein Metabolism Section, Translational Vascular Medicine Branch, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, Maryland 20892, United States
| | - Alan T. Remaley
- Lipoprotein Metabolism Section, Translational Vascular Medicine Branch, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, Maryland 20892, United States
| | - Martin F. Jarrold
- Department of Chemistry, Indiana University, Bloomington, Indiana 47405, United States
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Sanders JD, Grinfeld D, Aizikov K, Makarov A, Holden DD, Brodbelt JS. Determination of Collision Cross-Sections of Protein Ions in an Orbitrap Mass Analyzer. Anal Chem 2018; 90:5896-5902. [DOI: 10.1021/acs.analchem.8b00724] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Affiliation(s)
- James D. Sanders
- Department of Chemistry University of Texas at Austin Austin, Texas 78712, United States
| | | | | | | | - Dustin D. Holden
- Department of Chemistry University of Texas at Austin Austin, Texas 78712, United States
| | - Jennifer S. Brodbelt
- Department of Chemistry University of Texas at Austin Austin, Texas 78712, United States
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42
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Abstract
The relationship between mass and charge has been a crucial topic in mass spectrometry (MS) because the mass itself is typically evaluated based on the m/z ratio. Despite the fact that this measurement is indirect, a precise mass can be obtained from the m/z value with a high m/z resolution up to 105 for samples in the low mass and low charge region under 10,000 Da and 20 e, respectively. However, the target of MS has recently been expanded to the very heavy region of Mega or Giga Da, which includes large particles and biocomplexes, with very large and widely distributed charge from kilo to Mega range. In this region, it is necessary to evaluate charge and mass simultaneously. Recent studies for simultaneous mass and charge observation and related phenomena are discussed in this review.
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Affiliation(s)
- Toshiki Sugai
- Department of Chemistry, Faculty of Science, Toho University
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