Editorial

10 pages, 262 KiB

Open AccessEditorial

Special Issue with Research Topics on “Recent Analysis and Applications of Mass Spectra on Biochemistry”

by Bojidarka Ivanova

Int. J. Mol. Sci. 2024, 25(4), 1995; https://doi.org/10.3390/ijms25041995 - 07 Feb 2024

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Analytical mass spectrometry applies irreplaceable mass spectrometric (MS) methods to analytical chemistry and chemical analysis, among other areas of analytical science [...] Full article

(This article belongs to the Special Issue Recent Analysis and Applications of Mass Spectrum on Biochemistry)

Research

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30 pages, 5100 KiB

Open AccessArticle

Mass Spectrometric Identification of Metabolites after Magnetic-Pulse Treatment of Infected Pyrus communis L. Microplants

by Mikhail Upadyshev, Bojidarka Ivanova and Svetlana Motyleva

Int. J. Mol. Sci. 2023, 24(23), 16776; https://doi.org/10.3390/ijms242316776 - 26 Nov 2023

Cited by 1 | Viewed by 1095

Abstract

The major goal of this study is to create a venue for further work on the effect of pulsed magnetic fields on plant metabolism. It deals with metabolite synthesis in the aforementioned conditions in microplants of Pyrus communis L. So far, there have [...] Read more.

The major goal of this study is to create a venue for further work on the effect of pulsed magnetic fields on plant metabolism. It deals with metabolite synthesis in the aforementioned conditions in microplants of Pyrus communis L. So far, there have been glimpses into the governing factors of plant biochemistry in vivo, and low-frequency pulsed magnestatic fields have been shown to induce additional electric currents in plant tissues, thus perturbing the value of cell membrane potential and causing the biosynthesis of new metabolites. In this study, sixty-seven metabolites synthesized in microplants within 3–72 h after treatment were identified and annotated. In total, thirty-one metabolites were produced. Magnetic-pulse treatment caused an 8.75-fold increase in the concentration of chlorogenic acid (RT = 8.33 ± 0.01₉₇ min) in tissues and the perturbation of phenolic composition. Aucubin, which has antiviral and antistress biological activity, was identified as well. This study sheds light on the effect of magnetic fields on the biochemistry of low-molecular-weight metabolites of pear plants in vitro, thus providing in-depth metabolite analysis under optimized synthetic conditions. This study utilized high-resolution gas chromatography-mass spectrometry, metabolomics methods, stochastic dynamics mass spectrometry, quantum chemistry, and chemometrics, respectively. Stochastic dynamics uses the relationships between measurands and molecular structures of silylated carbohydrates, showing virtually identical mass spectra and comparable chemometrics parameters. Full article

(This article belongs to the Special Issue Recent Analysis and Applications of Mass Spectrum on Biochemistry)

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29 pages, 1281 KiB

Open AccessArticle

Two-Dimensional Polyacrylamide Gel Electrophoresis Coupled with Nanoliquid Chromatography–Tandem Mass Spectrometry-Based Identification of Differentially Expressed Proteins and Tumorigenic Pathways in the MCF7 Breast Cancer Cell Line Transfected for Jumping Translocation Breakpoint Protein Overexpression

by Madhuri Jayathirtha, Taniya Jayaweera, Danielle Whitham, Brîndușa Alina Petre, Anca-Narcisa Neagu and Costel C. Darie

Int. J. Mol. Sci. 2023, 24(19), 14714; https://doi.org/10.3390/ijms241914714 - 28 Sep 2023

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Abstract

The identification of new genes/proteins involved in breast cancer (BC) occurrence is widely used to discover novel biomarkers and understand the molecular mechanisms of BC initiation and progression. The jumping translocation breakpoint (JTB) gene may act both as a tumor suppressor [...] Read more.

The identification of new genes/proteins involved in breast cancer (BC) occurrence is widely used to discover novel biomarkers and understand the molecular mechanisms of BC initiation and progression. The jumping translocation breakpoint (JTB) gene may act both as a tumor suppressor or oncogene in various types of tumors, including BC. Thus, the JTB protein could have the potential to be used as a biomarker in BC, but its neoplastic mechanisms still remain unknown or controversial. We previously analyzed the interacting partners of JTB^high protein extracted from transfected MCF7 BC cell line using SDS-PAGE complemented with in-solution digestion, respectively. The previous results suggested the JTB contributed to the development of a more aggressive phenotype and behavior for the MCF7 BC cell line through synergistic upregulation of epithelial–mesenchymal transition (EMT), mitotic spindle, and fatty acid metabolism-related pathways. In this work, we aim to complement the previously reported JTB proteomics-based experiments by investigating differentially expressed proteins (DEPs) and tumorigenic pathways associated with JTB overexpression using two-dimensional polyacrylamide gel electrophoresis (2D-PAGE). Statistically different gel spots were picked for protein digestion, followed by nanoliquid chromatography–tandem mass spectrometry (nLC-MS/MS) analysis. We identified six DEPs related to the JTB^high condition vs. control that emphasize a pro-tumorigenic (PT) role. Twenty-one proteins, which are known to be usually overexpressed in cancer cells, emphasize an anti-tumorigenic (AT) role when low expression occurs. According to our previous results, proteins that have a PT role are mainly involved in the activation of the EMT process. Interestingly, JTB overexpression has been correlated here with a plethora of significant upregulated and downregulated proteins that sustain JTB tumor suppressive functions. Our present and previous results sustain the necessity of the complementary use of different proteomics-based methods (SDS-PAGE, 2D-PAGE, and in-solution digestion) followed by tandem mass spectrometry to avoid their limitations, with each method leading to the delineation of specific clusters of DEPs that may be merged for a better understanding of molecular pathways and neoplastic mechanisms related to the JTB’s role in BC initiation and progression. Full article

(This article belongs to the Special Issue Recent Analysis and Applications of Mass Spectrum on Biochemistry)

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11 pages, 2034 KiB

Open AccessArticle

Identification of Antibody-Mediated Hydrolysis Sites of Oligopeptides Corresponding to the SARS-CoV-2 S-Protein by MALDI-TOF Mass Spectrometry

by Anna M. Timofeeva, Sergey E. Sedykh, Pavel S. Dmitrenok and Georgy A. Nevinsky

Int. J. Mol. Sci. 2023, 24(18), 14342; https://doi.org/10.3390/ijms241814342 - 20 Sep 2023

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Abstract

Antibodies recognizing RBD and the S-protein have been previously demonstrated to be formed in humans after SARS-CoV-2 infection and vaccination with the Sputnik V adenovirus vaccine. These antibodies were found to be active when hydrolyzing FITC-labeled oligopeptides corresponding to linear epitopes of the [...] Read more.

Antibodies recognizing RBD and the S-protein have been previously demonstrated to be formed in humans after SARS-CoV-2 infection and vaccination with the Sputnik V adenovirus vaccine. These antibodies were found to be active when hydrolyzing FITC-labeled oligopeptides corresponding to linear epitopes of the S-protein. The thin-layer chromatography method allows the relative accumulation of the reaction product to be estimated but cannot identify hydrolysis sites. This study used the MALDI-TOF MS method to establish oligopeptide hydrolysis sites. Using the MALDI-TOF MS method in combination with the analysis of known hydrolysis sites characteristic of canonical proteases allowed us to establish the unique hydrolysis sites inherent only to catalytically active antibodies. We have discovered two 12-mer oligopeptides to have six hydrolysis sites equally distributed throughout the oligopeptide. The other three oligopeptides were found to have two to three closely spaced hydrolysis sites. In contrast to trypsin and chymotrypsin proteases, the catalytically active antibodies of COVID-19 patients have their peptide bond hydrolyzed mainly after proline, threonine, glycine, or serine residues. Here, we propose a new high-throughput experimental method for analyzing the proteolytic activity of natural antibodies produced in viral pathology. Full article

(This article belongs to the Special Issue Recent Analysis and Applications of Mass Spectrum on Biochemistry)

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19 pages, 3798 KiB

Open AccessArticle

Proteome-Level Investigation of Vitis amurensis Calli Transformed with a Constitutively Active, Ca²⁺-Independent Form of the Arabidopsis AtCPK1 Gene

by Galina N. Veremeichik, Dmitry V. Bulgakov, Yuliya A. Konnova, Evgenia V. Brodovskaya, Valeria P. Grigorchuk and Victor P. Bulgakov

Int. J. Mol. Sci. 2023, 24(17), 13184; https://doi.org/10.3390/ijms241713184 - 24 Aug 2023

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Abstract

Calcium-dependent protein kinases (CDPKs) are one of the main Ca²⁺ decoders in plants. Among them, Arabidopsis thaliana AtCPK1 is one of the most studied CDPK genes as a positive regulator of plant responses to biotic and abiotic stress. The mutated form of [...] Read more.

Calcium-dependent protein kinases (CDPKs) are one of the main Ca²⁺ decoders in plants. Among them, Arabidopsis thaliana AtCPK1 is one of the most studied CDPK genes as a positive regulator of plant responses to biotic and abiotic stress. The mutated form of AtCPK1, in which the autoinhibitory domain is inactivated (AtCPK1-Ca), provides constitutive kinase activity by mimicking a stress-induced increase in the Ca²⁺ flux. In the present study, we performed a proteomic analysis of Vitis amurensis calli overexpressing the AtCPK1-Ca form using untransformed calli as a control. In our previous studies, we have shown that the overexpression of this mutant form leads to the activation of secondary metabolism in plant cell cultures, including an increase in resveratrol biosynthesis in V. amurensis cell cultures. We analyzed upregulated and downregulated proteins in control and transgenic callus cultures using two-dimensional gel electrophoresis, and Matrix-assisted laser desorption and ionization time-of-flight mass spectrometry (MALDI-TOF). In calli transformed with AtCPK1-Ca, an increased amounts of pathogenesis-related proteins were found. A quantitative real-time PCR analysis confirmed this result. Full article

(This article belongs to the Special Issue Recent Analysis and Applications of Mass Spectrum on Biochemistry)

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19 pages, 4105 KiB

Open AccessArticle

Chemical, Aroma and Pro-Health Characteristics of Kaffir Lime Juice—The Approach Using Optimized HS-SPME-GC-TOFMS, MP-OES, 3D-FL and Physiochemical Analysis

by Martyna Lubinska-Szczygeł, Żaneta Polkowska, Małgorzata Rutkowska and Shela Gorinstein

Int. J. Mol. Sci. 2023, 24(15), 12410; https://doi.org/10.3390/ijms241512410 - 03 Aug 2023

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Abstract

The study aimed to provide the chemical, aroma and prohealth characteristics of the kaffir lime juice. A procedure using solid-phase microextraction with gas chromatography (SPME-GC-TOFMS) was optimized and validated for the determination of terpenes of kaffir lime. Main physicochemical parameters: pH, vitamin C, [...] Read more.

The study aimed to provide the chemical, aroma and prohealth characteristics of the kaffir lime juice. A procedure using solid-phase microextraction with gas chromatography (SPME-GC-TOFMS) was optimized and validated for the determination of terpenes of kaffir lime. Main physicochemical parameters: pH, vitamin C, citric acid and °Brix were evaluated. Micro- and macro elements were determined using microwave plasma optic emission spectrometry (MP-OES). The binding of kaffir lime terpenes to human serum albumin (HSA) was investigated by fluorescence spectroscopy (3D-FL). β-Pinene and Limonene were selected as the most abundant terpenes with the concentration of 1225 ± 35 and 545 ± 16 µg/g, respectively. The values of citric acid, vitamin C, °Brix and pH were 74.74 ± 0.50 g/kg, 22.31 ± 0.53 mg/100 mL, 10.35 ± 0.70 and 2.406 ± 0.086 for, respectively. Iron, with a concentration of 16.578 ± 0.029 mg/kg, was the most abundant microelement. Among the macroelements, potassium (8121 ± 52 mg/kg) was dominant. Kaffir lime binding to HSA was higher than β-Pinene, which may indicate the therapeutic effect of the juice. Kaffir lime juice is a source of terpenes with good aromatic and bioactive properties. Fluorescence measurements confirmed its therapeutic effect. Kaffir lime juice is also a good source of citric acid with potential industrial application. The high content of minerals compared to other citruses increases its prohealth value. Full article

(This article belongs to the Special Issue Recent Analysis and Applications of Mass Spectrum on Biochemistry)

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21 pages, 3762 KiB

Open AccessArticle

Optimization of Mass Spectrometry Imaging for Drug Metabolism and Distribution Studies in the Zebrafish Larvae Model: A Case Study with the Opioid Antagonist Naloxone

by Yu Mi Park, Markus R. Meyer, Rolf Müller and Jennifer Herrmann

Int. J. Mol. Sci. 2023, 24(12), 10076; https://doi.org/10.3390/ijms241210076 - 13 Jun 2023

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Abstract

Zebrafish (ZF; Danio rerio) larvae have emerged as a promising in vivo model in drug metabolism studies. Here, we set out to ready this model for integrated mass spectrometry imaging (MSI) to comprehensively study the spatial distribution of drugs and their metabolites [...] Read more.

Zebrafish (ZF; Danio rerio) larvae have emerged as a promising in vivo model in drug metabolism studies. Here, we set out to ready this model for integrated mass spectrometry imaging (MSI) to comprehensively study the spatial distribution of drugs and their metabolites inside ZF larvae. In our pilot study with the overall goal to improve MSI protocols for ZF larvae, we investigated the metabolism of the opioid antagonist naloxone. We confirmed that the metabolic modification of naloxone is in high accordance with metabolites detected in HepaRG cells, human biosamples, and other in vivo models. In particular, all three major human metabolites were detected at high abundance in the ZF larvae model. Next, the in vivo distribution of naloxone was investigated in three body sections of ZF larvae using LC-HRMS/MS showing that the opioid antagonist is mainly present in the head and body sections, as suspected from published human pharmacological data. Having optimized sample preparation procedures for MSI (i.e., embedding layer composition, cryosectioning, and matrix composition and spraying), we were able to record MS images of naloxone and its metabolites in ZF larvae, providing highly informative distributional images. In conclusion, we demonstrate that all major ADMET (absorption, distribution, metabolism, excretion, and toxicity) parameters, as part of in vivo pharmacokinetic studies, can be assessed in a simple and cost-effective ZF larvae model. Our established protocols for ZF larvae using naloxone are broadly applicable, particularly for MSI sample preparation, to various types of compounds, and they will help to predict and understand human metabolism and pharmacokinetics. Full article

(This article belongs to the Special Issue Recent Analysis and Applications of Mass Spectrum on Biochemistry)

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Graphical abstract

15 pages, 2428 KiB

Open AccessArticle

Serum Vitamin D Metabolites by HPLC-MS/MS Combined with Differential Ion Mobility Spectrometry: Aspects of Sample Preparation without Derivatization

by Liliia Usoltseva, Vitaliy Ioutsi, Yuriy Panov, Mariya Antsupova, Liudmila Rozhinskaya, Galina Melnichenko and Natalia Mokrysheva

Int. J. Mol. Sci. 2023, 24(9), 8111; https://doi.org/10.3390/ijms24098111 - 30 Apr 2023

Cited by 3 | Viewed by 1509

Abstract

In current clinical practice, a thorough understanding of vitamin D metabolism is in high demand both for patients with various diseases and for healthy individuals. Analytical techniques that provide simultaneous measurement of multiple metabolites are preferred. Herein, the development of an HPLC-DMS-MS/MS method [...] Read more.

In current clinical practice, a thorough understanding of vitamin D metabolism is in high demand both for patients with various diseases and for healthy individuals. Analytical techniques that provide simultaneous measurement of multiple metabolites are preferred. Herein, the development of an HPLC-DMS-MS/MS method for the quantitation of vitamin D compounds (25(OH)D₃, 25(OH)D₂, 1,25(OH)₂D₃, 3-epi-25(OH)D₃, 24,25(OH)₂D₃, and D₃) in serum is described. The selected sample preparation procedure based on the combination of liquid–liquid and solid-phase extraction, which excluded a lengthy derivatization step, was compared with other common approaches. Sensitivity was increased through the implementation of differential ion mobility separation. The proposed assay allowed us to determine the low abundant 1,25(OH)₂D₃ with the detection limit of 10 pg/mL. The validation study showed good linearity (r² > 0.99), a wide analytical range (2.5–75 ng/mL for 25(OH)D₃), and acceptable precision (<7%) for all metabolites. The recovery ranged from 71% to 93% and the matrix effect from 0.80 to 0.95 depending on the metabolite; accuracy determination was performed using DEQAS controls. Full article

(This article belongs to the Special Issue Recent Analysis and Applications of Mass Spectrum on Biochemistry)

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11 pages, 997 KiB

Open AccessCommunication

New Perspectives of Multiplex Mass Spectrometry Blood Protein Quantification on Microsamples in Biological Monitoring of Elderly Patients

by Jérôme Vialaret, Margaux Vignon, Stéphanie Badiou, Gregory Baptista, Laura Fichter, Anne-Marie Dupuy, Aleksandra Maleska Maceski, Martin Fayolle, Mehdi Brousse, Jean-Paul Cristol, Claude Jeandel, Christophe Hirtz and Sylvain Lehmann

Int. J. Mol. Sci. 2023, 24(8), 6989; https://doi.org/10.3390/ijms24086989 - 10 Apr 2023

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Abstract

Blood microsampling combined with large panels of clinically relevant tests are of major interest for the development of home sampling and predictive medicine. The aim of the study was to demonstrate the practicality and medical utility of microsamples quantification using mass spectrometry (MS) [...] Read more.

Blood microsampling combined with large panels of clinically relevant tests are of major interest for the development of home sampling and predictive medicine. The aim of the study was to demonstrate the practicality and medical utility of microsamples quantification using mass spectrometry (MS) in a clinical setting by comparing two types of microsamples for multiplex MS protein detection. In a clinical trial based on elderly population, we compared 2 µL of plasma to dried blood spot (DBS) with a clinical quantitative multiplex MS approach. The analysis of the microsamples allowed the quantification of 62 proteins with satisfactory analytical performances. A total of 48 proteins were significantly correlated between microsampling plasma and DBS (p < 0.0001). The quantification of 62 blood proteins allowed us to stratify patients according to their pathophysiological status. Apolipoproteins D and E were the best biomarker link to IADL (instrumental activities of daily living) score in microsampling plasma as well as in DBS. It is, thus, possible to detect multiple blood proteins from micro-samples in compliance with clinical requirements and this allows, for example, to monitor the nutritional or inflammatory status of patients. The implementation of this type of analysis opens new perspectives in the field of diagnosis, monitoring and risk assessment for personalized medicine approaches. Full article

(This article belongs to the Special Issue Recent Analysis and Applications of Mass Spectrum on Biochemistry)

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21 pages, 3809 KiB

Open AccessArticle

Stochastic Dynamic Mass Spectrometric Quantitative and Structural Analyses of Pharmaceutics and Biocides in Biota and Sewage Sludge

by Bojidarka Ivanova

Int. J. Mol. Sci. 2023, 24(7), 6306; https://doi.org/10.3390/ijms24076306 - 27 Mar 2023

Cited by 5 | Viewed by 1328

Abstract

Mass spectrometric innovations in analytical instrumentation tend to be accompanied by the development of a data-processing methodology, expecting to gain molecular-level insights into real-life objects. Qualitative and semi-quantitative methods have been replaced routinely by precise, accurate, selective, and sensitive quantitative ones. Currently, mass [...] Read more.

Mass spectrometric innovations in analytical instrumentation tend to be accompanied by the development of a data-processing methodology, expecting to gain molecular-level insights into real-life objects. Qualitative and semi-quantitative methods have been replaced routinely by precise, accurate, selective, and sensitive quantitative ones. Currently, mass spectrometric 3D molecular structural methods are attractive. As an attempt to establish a reliable link between quantitative and 3D structural analyses, there has been developed an innovative formula [

D_{S D}^{″, t o t} = \sum_{i}^{n} D_{S D}^{″, i} = \sum_{i}^{n} {2.6388.10}^{- 17} \times \bar{I_{i}^{2}} - {(\bar{I_{i}})}^{2}

] capable of the exact determination of the analyte amount and its 3D structure. It processed, herein, ultra-high resolution mass spectrometric variables of paracetamol, atenolol, propranolol, and benzalkonium chlorides in biota, using mussel tissue and sewage sludge. Quantum chemistry and chemometrics were also used. Results: Data on mixtures of antibiotics and surfactants in biota and the linear dynamic range of concentrations 2–80 ng.(mL)⁻¹ and collision energy CE = 5–60 V are provided. Quantitative analysis of surfactants in biota via calibration equation ln[D″_SD] = f(conc.) yields the exact parameter |r| = 0.9999₁, examining the peaks of BAC-C12 at m/z 212.209 ± 0.1 and 211.75 ± 0.15 for tautomers of fragmentation ions. Exact parameter |r| = 1 has been obtained, correlating the theory and experiments in determining the 3D molecular structures of ions of paracetamol at m/z 152, 158, 174, 301, and 325 in biota. Full article

(This article belongs to the Special Issue Recent Analysis and Applications of Mass Spectrum on Biochemistry)

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Review

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36 pages, 6355 KiB

Open AccessReview

Quantitative Mass Spectrometry Characterizes Client Spectra of Components for Targeting of Membrane Proteins to and Their Insertion into the Membrane of the Human ER

by Martin Jung and Richard Zimmermann

Int. J. Mol. Sci. 2023, 24(18), 14166; https://doi.org/10.3390/ijms241814166 - 15 Sep 2023

Cited by 2 | Viewed by 1107

Abstract

To elucidate the redundancy in the components for the targeting of membrane proteins to the endoplasmic reticulum (ER) and/or their insertion into the ER membrane under physiological conditions, we previously analyzed different human cells by label-free quantitative mass spectrometry. The HeLa and HEK293 [...] Read more.

To elucidate the redundancy in the components for the targeting of membrane proteins to the endoplasmic reticulum (ER) and/or their insertion into the ER membrane under physiological conditions, we previously analyzed different human cells by label-free quantitative mass spectrometry. The HeLa and HEK293 cells had been depleted of a certain component by siRNA or CRISPR/Cas9 treatment or were deficient patient fibroblasts and compared to the respective control cells by differential protein abundance analysis. In addition to clients of the SRP and Sec61 complex, we identified membrane protein clients of components of the TRC/GET, SND, and PEX3 pathways for ER targeting, and Sec62, Sec63, TRAM1, and TRAP as putative auxiliary components of the Sec61 complex. Here, a comprehensive evaluation of these previously described differential protein abundance analyses, as well as similar analyses on the Sec61-co-operating EMC and the characteristics of the topogenic sequences of the various membrane protein clients, i.e., the client spectra of the components, are reported. As expected, the analysis characterized membrane protein precursors with cleavable amino-terminal signal peptides or amino-terminal transmembrane helices as predominant clients of SRP, as well as the Sec61 complex, while precursors with more central or even carboxy-terminal ones were found to dominate the client spectra of the SND and TRC/GET pathways for membrane targeting. For membrane protein insertion, the auxiliary Sec61 channel components indeed share the client spectra of the Sec61 complex to a large extent. However, we also detected some unexpected differences, particularly related to EMC, TRAP, and TRAM1. The possible mechanistic implications for membrane protein biogenesis at the human ER are discussed and can be expected to eventually advance our understanding of the mechanisms that are involved in the so-called Sec61-channelopathies, resulting from deficient ER protein import. Full article

(This article belongs to the Special Issue Recent Analysis and Applications of Mass Spectrum on Biochemistry)

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14 pages, 3612 KiB

Open AccessReview

NanoLC-EI-MS: Perspectives in Biochemical Analysis

by Natalia Gabrielly Pereira dos Santos, Edvaldo Vasconcelos Soares Maciel, Deyber Arley Vargas Medina and Fernando Mauro Lanças

Int. J. Mol. Sci. 2023, 24(14), 11746; https://doi.org/10.3390/ijms241411746 - 21 Jul 2023

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Abstract

Although LC-MS with atmospheric pressure ionization (API) sources is the primary technique used in modern bioanalytical studies, electron ionization mass spectrometry (EI-MS) can provide some substantial advantages over it. EI-MS is a matrix effect-free technique that provides reproducible and comparable mass spectra, serving [...] Read more.

Although LC-MS with atmospheric pressure ionization (API) sources is the primary technique used in modern bioanalytical studies, electron ionization mass spectrometry (EI-MS) can provide some substantial advantages over it. EI-MS is a matrix effect-free technique that provides reproducible and comparable mass spectra, serving as a compound fingerprint for easy identification through automated comparison with spectral libraries. Leveraging EI-MS in biochemical studies can yield critical analytical benefits for targeted and untargeted analyses. However, to fully utilize EI-MS for heavy and non-volatile molecules, a new technology that enables the coupling of liquid chromatography with EI-MS is needed. Recent advancements in nanoLC have addressed the compatibility issues between LC and EI-MS, and innovative interfacing strategies such as Direct-EI, liquid electron ionization (LEI), and Cold-EI have extended the application of EI-MS beyond the determination of volatile organic molecules. This review provides an overview of the latest developments in nanoLC-EI-MS interfacing technologies, discussing their scope and limitations. Additionally, selected examples of nanoLC-EI-MS applications in the field of biochemical analysis are presented, highlighting the potential prospects and benefits that the establishment of this technique can bring to this field. Full article

(This article belongs to the Special Issue Recent Analysis and Applications of Mass Spectrum on Biochemistry)

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