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Ninomiya S, Rankin-Turner S, Akashi S, Hiraoka K. Solvent effect on the detection of peptides and proteins by nanoelectrospray ionization mass spectrometry: Anomalous behavior of aqueous 2-propanol. Anal Biochem 2024; 688:115461. [PMID: 38244751 DOI: 10.1016/j.ab.2024.115461] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2023] [Revised: 11/13/2023] [Accepted: 01/13/2024] [Indexed: 01/22/2024]
Abstract
To investigate the solvent effect on the detection of peptides and proteins, nanoelectrospray mass spectra were measured for mixtures of 1 % acetic acid and 5 × 10-6 M gramicidin S (G), ubiquitin (U), and cytochrome c (C) in water (W), methanol (MeOH), 1-propanol (1-PrOH), acetonitrile (AcN), and 2-propanol (2-PrOH). Although doubly protonated G (G2+) and multiply protonated U (Un+) and C (Cn+) were readily detected with a wide range of mixing ratios of W solutions for MeOH, 1-PrOH, and AcN, Cn+ was totally suppressed for the solutions with mixing ratios (v/v) of W/2-PrOH (50/50) and (70/30). However, denatured Cn+ started to be detected with W/2-PrOH (90/10) together with Gn+ (n = 1, 2) and native Un+ (n = 6-8). At the mixing ratio of W/2-PrOH (95/5), native Cn+ (n = 7-10) together with Gn+ (n = 1, 2) and native Un+ (n = 6-8) were detected with high ion intensities. The use of W/2-PrOH (95/5) is profitable because it enables the detection of native proteins with high detection sensitivities.
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Affiliation(s)
- Satoshi Ninomiya
- Clean Energy Research Center, University of Yamanashi, 4-3-11 Takeda, Kofu, Yamanashi, 400-8511, Japan.
| | - Stephanie Rankin-Turner
- Department of Molecular Microbiology & Immunology, Johns Hopkins Bloomberg School of Public Health, 615 N. Wolfe Street, Baltimore, MD, 21205, USA
| | - Satoko Akashi
- Graduate School of Medical Life Science, Yokohama-City University, 1-7-29 Suehiro-cho, Tsurumi-ku, Yokohama, Kanagawa, 230-0045, Japan
| | - Kenzo Hiraoka
- Clean Energy Research Center, University of Yamanashi, 4-3-11 Takeda, Kofu, Yamanashi, 400-8511, Japan.
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Jordan JS, Lee KJ, Williams ER. Overcoming aggregation with laser heated nanoelectrospray mass spectrometry: thermal stability and pathways for loss of bicarbonate from carbonic anhydrase II. Analyst 2024; 149:2281-2290. [PMID: 38497240 DOI: 10.1039/d4an00229f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/19/2024]
Abstract
Variable temperature electrospray mass spectrometry is useful for multiplexed measurements of the thermal stabilities of biomolecules, but the ionization process can be disrupted by aggregation-prone proteins/complexes that have irreversible unfolding transitions. Resistively heating solutions containing a mixture of bovine carbonic anhydrase II (BCAII), a CO2 fixing enzyme involved in many biochemical pathways, and cytochrome c leads to complete loss of carbonic anhydrase signal and a significant reduction in cytochrome c signal above ∼72 °C due to aggregation. In contrast, when the tips of borosilicate glass nanoelectrospray emitters are heated with a laser, complete thermal denaturation curves for both proteins are obtained in <1 minute. The simultaneous measurements of the melting temperature of BCAII and BCAII bound to bicarbonate reveal that the bicarbonate stabilizes the folded form of this protein by ∼6.4 °C. Moreover, the temperature dependences of different bicarbonate loss pathways are obtained. Although protein analytes are directly heated by the laser for only 140 ms, heat conduction further up the emitter leads to a total analyte heating time of ∼41 s. Pulsed laser heating experiments could reduce this time to ∼0.5 s for protein aggregation that occurs on a faster time scale. Laser heating provides a powerful method for studying the detailed mechanisms of cofactor/ligand loss with increasing temperature and promises a new tool for studying the effect of ligands, drugs, growth conditions, buffer additives, or other treatments on the stabilities of aggregation-prone biomolecules.
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Affiliation(s)
- Jacob S Jordan
- Department of Chemistry, University of California, Berkeley, California, 94720-1460, USA.
| | - Katherine J Lee
- 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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Jordan JS, Williams ER. Laser Heating Nanoelectrospray Emitters for Fast Protein Melting Measurements with Mass Spectrometry. Anal Chem 2022; 94:16894-16900. [DOI: 10.1021/acs.analchem.2c04204] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Affiliation(s)
- Jacob S. Jordan
- Department of Chemistry, University of California, Berkeley, California 94720, United States
| | - Evan R. Williams
- Department of Chemistry, University of California, Berkeley, California 94720, United States
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Ninomiya S, Hiraoka K. Pulsed Nano-Electrospray Ionization with a High Voltage (4000 V) Pulse Applied to Solutions in the Range of 200 ns to 1 ms. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2020; 31:693-699. [PMID: 31977219 DOI: 10.1021/jasms.9b00099] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
To initiate electrospray, it is necessary to accumulate excess charges on the liquid surface until the outward electrostatic pressure (PE) overwhelms the inward pressure Pγ originating from the surface tension of the liquid droplet. In this report, electrospray mass spectrometry for solutions of gramicidin S (G), ubiquitin (U), and cytochrome c (C) in H2O/CH3OH (1/1) was performed as a function of the high voltage (4000 V) pulse width in the range of 200 ns to 1 ms using a 4 μm i.d. glass capillary. Multiply protonated ions for all three samples started to be detected with the 300 μs pulse width. Denaturation of C and U proceeded with an increase of the pulse width. When the bias voltage of ∼880 V that was lower than the threshold voltage for the generation of continuous electrospray (∼1000 V) was applied to the solution, multiply protonated G, U, and C were detected with the 200 ns pulse width. After the depletion of excess charges in 200 ns, it took 10-100 μs to regenerate electrospray.
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Affiliation(s)
- Satoshi Ninomiya
- Graduate Faculty of Interdisciplinary Research, University of Yamanashi, 4-3-11, Takeda, Kofu 400-8511, Japan
| | - Kenzo Hiraoka
- Clean Energy Research Center, University of Yamanashi, 4-3-11, Takeda, Kofu, Yamanashi 400-8511, Japan
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Li G, Zheng S, Chen Y, Hou Z, Huang G. Reliable Tracking In-Solution Protein Unfolding via Ultrafast Thermal Unfolding/Ion Mobility-Mass Spectrometry. Anal Chem 2018; 90:7997-8001. [PMID: 29894165 DOI: 10.1021/acs.analchem.8b00859] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Sequential unfolding of monomeric proteins is important for the global understanding of local conformational elements (e.g., secondary structures and domain connections) within those protein assemblies. Ion mobility-mass spectrometry (IM-MS) is an emerging and promising technique for probing gradual protein structural perturbations in the gas phase. However, it is still challenging to track sequential unfolding in the solution phase. Here, we extended IM-MS to track in-solution sequential unfolding of monomeric proteins having single and/or multidomains. The present method combines ultrafast local heating effect (LHE)-driven sequential unfolding with IM-MS identification. Protein sequential unfolding in solution is demonstrated by the rapid and controllable IM-MS data switch between native and gradually unfolded states. Our results show that LHE induces gradual protein conformational transitions associated with biological functions, where IM-MS tracks the sequential unfolding of monomeric proteins.
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Lu Y, Pieterse CL, Robertson WD, Miller RJD. Soft Picosecond Infrared Laser Extraction of Highly Charged Proteins and Peptides from Bulk Liquid Water for Mass Spectrometry. Anal Chem 2018. [PMID: 29522677 DOI: 10.1021/acs.analchem.7b04306] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
We report the soft laser extraction and production of highly charged peptide and protein ions for mass spectrometry directly from bulk liquid water at atmospheric pressure and room temperature, using picosecond infrared laser ablation. Stable ion signal from singly charged small molecules, as well as highly charged biomolecular ions, from aqueous solutions at low laser pulse fluence (∼0.3 J cm-2) is demonstrated. Sampling via single picosecond laser pulses is shown to extract less than 27 pL of volume from the sample, producing highly charged peptide and protein ions for mass spectrometry detection. The ablation and ion generation is demonstrated to be soft in nature, producing natively folded proteins ions under sample conditions described for native mass spectrometry. The method provides laser-based sampling flexibility, precision and control with highly charged ion production directly from water at low and near neutral pH. This approach does not require an additional ionization device or high voltage applied directly to the sample.
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Affiliation(s)
- Yinfei Lu
- Max Planck Institute for the Structure and Dynamics of Matter , Luruper Chaussee 149 , Hamburg 22761 , Germany
| | - Cornelius L Pieterse
- Max Planck Institute for the Structure and Dynamics of Matter , Luruper Chaussee 149 , Hamburg 22761 , Germany
| | - Wesley D Robertson
- Max Planck Institute for the Structure and Dynamics of Matter , Luruper Chaussee 149 , Hamburg 22761 , Germany
| | - R J Dwayne Miller
- Max Planck Institute for the Structure and Dynamics of Matter , Luruper Chaussee 149 , Hamburg 22761 , Germany
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Žūkienė R, Naučienė Z, Šilkūnienė G, Vanagas T, Gulbinas A, Zimkus A, Mildažienė V. Contribution of mitochondria to injury of hepatocytes and liver tissue by hyperthermia. MEDICINA-LITHUANIA 2017; 53:40-49. [PMID: 28256298 DOI: 10.1016/j.medici.2017.01.001] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 10/07/2016] [Revised: 12/15/2016] [Accepted: 01/02/2017] [Indexed: 11/28/2022]
Abstract
OBJECTIVE The aim of this study was to investigate functional changes of liver mitochondria within the experimentally modeled transition zone of radiofrequency ablation and to estimate possible contribution of these changes to the energy status of liver cells and the whole tissue. MATERIALS AND METHODS Experiments were carried out on mitochondria isolated from the perfused liver and isolated hepatocytes of male Wistar rats. Hyperthermia was induced by changing the temperature of perfusion medium in the range characteristic for the transition zone (38-52°C). After 15-min perfusion, mitochondria were isolated to investigate changes in the respiration rates and the membrane potential. Adenine nucleotides extracted from isolated hepatocytes and perfused liver subjected to hyperthermic treatment were analyzed by HPLC. RESULTS Hyperthermic liver perfusion at 42-52°C progressively impaired oxidative phosphorylation in isolated mitochondria. Significant inhibition of the respiratory chain components was observed after perfusion at 42°C, irreversible uncoupling became evident after liver perfusion at higher temperatures (46°C and above). After perfusion at 50-52°C energy supplying function of mitochondria was entirely compromised, and mitochondria turned to energy consumers. Hyperthermia-induced changes in mitochondrial function correlated well with changes in the energy status and viability of isolated hepatocytes, but not with the changes in the energy status of the whole liver tissue. CONCLUSIONS In this study the pattern of the adverse changes in mitochondrial functions that are progressing with increase in liver perfusion temperature was established. Results of experiments on isolated mitochondria and isolated hepatocytes indicate that hyperthermic treatment significantly and irreversibly inhibits energy-supplying function of mitochondria under conditions similar to those existing in the radiofrequency ablation transition zone and these changes can lead to death of hepatocytes. However, it was not possible to estimate contribution of mitochondrial injury to liver tissue energy status by estimating only hyperthermia-induced changes in adenine nucleotide amounts on the whole tissue level.
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Affiliation(s)
- Rasa Žūkienė
- Faculty of Natural Sciences, Vytautas Magnus University, Kaunas, Lithuania
| | - Zita Naučienė
- Faculty of Natural Sciences, Vytautas Magnus University, Kaunas, Lithuania
| | - Giedrė Šilkūnienė
- Faculty of Natural Sciences, Vytautas Magnus University, Kaunas, Lithuania
| | - Tomas Vanagas
- Department of Surgery, Medical Academy, Lithuanian University of Health Sciences, Kaunas, Lithuania
| | - Antanas Gulbinas
- Institute for Digestive Research, Medical Academy, Lithuanian University of Health Sciences, Kaunas, Lithuania
| | - Aurelijus Zimkus
- Institute of Biosciences, Vilnius University Life Sciences Center, Vilnius, Lithuania
| | - Vida Mildažienė
- Faculty of Natural Sciences, Vytautas Magnus University, Kaunas, Lithuania.
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Chen LC, Rahman MM, Hiraoka K. High pressure super-heated electrospray ionization mass spectrometry for sub-critical aqueous solution. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2014; 25:1862-1869. [PMID: 25204829 DOI: 10.1007/s13361-014-0974-0] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/21/2014] [Revised: 07/25/2014] [Accepted: 08/06/2014] [Indexed: 06/03/2023]
Abstract
The heating of electrospray ion source under atmospheric pressure is limited to the normal boiling point of the solution. The boiling takes place when the vapor pressure of the liquid at a given temperature equals the ambient pressure. By using a high pressure ESI source, which has been developed previously in our laboratory, a stable electrospray ionization of super-heated aqueous solution is performed up to a solution temperature of 180°C. The ion source is pressurized with pure nitrogen to a maximum pressure of 11 atm, and it is coupled to a commercial mass spectrometer via a custom-made ion transport capillary. A booster pump with variable pumping speed is added to the pumping system to regulate the pressure in the first pumping stage at 1 ~ 1.3 Torr. High pressure mass spectrometry is performed on several peptides and proteins to demonstrate its application in the temperature-controlled thermally induced denaturation and dissociation.
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Affiliation(s)
- Lee Chuin Chen
- Interdisciplinary Graduate School of Medicine and Engineering, University of Yamanashi, Kofu, Yamanashi, 400-8511, Japan,
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Sterling HJ, Cassou CA, Susa AC, Williams ER. Electrothermal supercharging of proteins in native electrospray ionization. Anal Chem 2012; 84:3795-801. [PMID: 22409200 DOI: 10.1021/ac300468a] [Citation(s) in RCA: 71] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
The formation of high charge-state protein ions with nanoelectrospray ionization (nESI) from purely aqueous ammonium bicarbonate solutions at neutral pH, where the proteins have native or native-like conformations prior to ESI droplet formation, is demonstrated. This "electrothermal" supercharging method depends on the temperature of the instrument entrance capillary, the nESI spray potential, and the solution ionic strength and buffer, although other factors almost certainly contribute. Mass spectra obtained with electrothermal supercharging appear similar to those obtained from denaturing solutions where charging beyond the total number of basic sites can be achieved. For example, a 17+ ion of bovine ubiquitin was formed by nESI of a 100 mM ammonium bicarbonate, pH 7.0, solution, which is three more charges than the total number of basic amino acids plus the N-terminus. Heating of the ESI droplets in the vacuum/atmosphere interface and the concomitant denaturation of the protein in the ESI droplets prior to ion formation appears to be the primary origin of the very high charge-state ions formed from these purely aqueous, buffered solutions. nESI mass spectra resembling those obtained under traditional native or denaturing conditions can be reversibly obtained simply by toggling the spray voltage between low and high values.
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Affiliation(s)
- Harry J Sterling
- Department of Chemistry, University of California, Berkeley, California 94720-1460, United States
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