Journal of the American Society for Mass Spectrometry最新文献

{"title":"Unified Fragmentation Pathways of Lithiated, Longer-Chain Acylglycerols Can Be Identified from Tandem Mass Spectrometry and Density Functional Computations.","authors":"J Stuart Grossert, Louis Ramaley","doi":"10.1021/jasms.4c00423","DOIUrl":"10.1021/jasms.4c00423","url":null,"abstract":"<p><p>We extend our previous work on the energetics and mechanisms of fragmentation in the mass spectrometry of triacylglycerols (TAGs). Previously, we proposed viable mechanisms for the collision-induced fragmentation of lithiated tripropionylglycerol using triple-quadrupole mass spectrometry. In this work, we used a QqLIT mass spectrometer to study both double- and triple-stage spectra from a range of TAGs having acid chains of types AAA (identical acid chains), AAB, ABA, and ABC, with chain lengths of 6-18 carbon atoms; we also studied some TAGs having a single double bond in the Δ-9 position. Detailed computations on fragmentation pathways were carried out on lithiated trihexanoylglycerol and on a limited number of longer chain ions. Second-stage fragmentations led to the formation of a lithiated ion after the loss of a neutral acid. With a further input of energy, this ion could rearrange into two other ions, one being formed more easily than the other. In a triple-stage fragmentation, these three ions give a defined series of product ions, some of which are characteristic of the substitution pattern on the glycerol core of the TAG. Computed reaction energies for product ion formation showed comparable trends to the relative intensities of the observed product ion spectra. These results have enabled us to propose unified mechanisms for the double- and triple-stage fragmentation of lithiated TAGs. The mechanisms have reasonable energetics, and all ions, as well as saddle points, have viable geometries. In addition, the fragmentation mechanisms are in accord with all the published experimental mass spectra.</p>","PeriodicalId":672,"journal":{"name":"Journal of the American Society for Mass Spectrometry","volume":" ","pages":"368-378"},"PeriodicalIF":3.1,"publicationDate":"2025-02-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142998196","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Synthesis and Characterization of Poly(ethylene furanoate)/Poly(ε-caprolactone) Block Copolymers.","authors":"Johan Stanley, Lidia Molina-Millán, Chrys Wesdemiotis, Ron M A Heeren, Alexandra Zamboulis, Lidija Fras Zemljič, Dimitra A Lambropoulou, Dimitrios N Bikiaris","doi":"10.1021/jasms.4c00397","DOIUrl":"10.1021/jasms.4c00397","url":null,"abstract":"<p><p>Biobased poly(ethylene furanoate) (PEF)/poly(ε-caprolactone) (PCL) block copolymers have been synthesized using ring opening polymerization (ROP) of ε-caprolactone (ε-CL) in the presence of PEF in different mass ratios. An increase in intrinsic viscosity is observed for the block copolymers with higher ε-CL content due to the extension of their macromolecular chain. Matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MS) was employed to understand the composition and structure of the produced block copolymers. The MS analysis helped to confirm the formation of PEF-PCL copolymers in all cases. Furthermore, tandem mass spectrometry experiments were performed to analyze the intrinsic fragmentation mechanism of neat PEF and PCL (both linear and cyclic) and confirm the block structure and end-groups. Finally, nuclear magnetic resonance results confirmed the composition and microstructure of the block copolymers. The synthesized PEF-PCL block copolymers can be used as a replacement for petroleum derived plastics, especially in the field of food packaging.</p>","PeriodicalId":672,"journal":{"name":"Journal of the American Society for Mass Spectrometry","volume":" ","pages":"286-298"},"PeriodicalIF":3.1,"publicationDate":"2025-02-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11809208/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142942355","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Locating Polyubiquitin Receptors on the 19S Regulatory Proteasome of <i>S. cerevisiae</i> by Cross-Linking Mass Spectrometry.","authors":"Yiran Ma, Bingqing Zhao, Amit K S Gautam, Caroline Davis, Jonathan C Trinidad, James P Reilly, David E Clemmer, Andreas Matouschek","doi":"10.1021/jasms.4c00381","DOIUrl":"10.1021/jasms.4c00381","url":null,"abstract":"<p><p>The effectiveness of state-of-the-art cross-linking strategies and mass spectrometry (MS) detection was explored in an important biological context, namely, the ubiquitin-proteasome system, which is responsible for most of the regulated protein degradation in eukaryotic cells. The locations of possible binding sites on the <i>S. cerevisiae</i> 19S proteasome regulatory particle for Lys⁴⁸ linked polyubiquitin chains were examined using cross-linking strategies and MS based detection by comparing two types of cross-linkers: a (bis)-sulfosuccinimidyl suberate (BS³) and diethyl suberothioimidate (DEST). The well-established BS³-based strategy produced 328 cross-linked peptides; however, no ubiquitin-19S cross-links were observed. The recently developed DEST-based approach produced fewer (146) linkages overall, but these included six ubiquitin-19S cross-links. Some of these cross-links are predicted by the canonical view of ubiquitin recognition, but others suggest novel insights into how the proteasome recognizes its substrates. A discussion of these strategies and structural implications for polyubiquitin-proteasome binding is provided.</p>","PeriodicalId":672,"journal":{"name":"Journal of the American Society for Mass Spectrometry","volume":" ","pages":"277-285"},"PeriodicalIF":3.1,"publicationDate":"2025-02-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143021506","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A Hybrid Vacuum Flange RF Oscillator for Low-Cost Mass Spectrometry.","authors":"Caraleigh G Smith, Brian H Clowers, Steven J Kregel","doi":"10.1021/jasms.4c00410","DOIUrl":"10.1021/jasms.4c00410","url":null,"abstract":"<p><p>In this communication we report the construction of a printed circuit board which mounts directly to the vacuum chamber of a mass spectrometer and produces the RF waveforms needed by many nonmass-selective devices such as ion guides and ion funnels. Our device is designed to replace a standard KF40 flange, can maintain vacuum chamber pressures of less than 10^-6 Torr, and contains the circuitry of the open-source Wisconsin Oscillator RF power supply to generate RF waveforms of 1-4 MHz and up to 200 V_p-p. In this iteration of the Wisconsin Oscillator, we also introduce a variable resistor to control the output RF amplitude and show that its ion transmission capabilities are identical to those provided by commercial RF power supplies. With this new implementation we have greatly reduced the space and monetary requirements for driving nonmass-selective ion manipulation devices, which we expect to be advantageous to those developing low-cost and/or portable mass spectrometry systems.</p>","PeriodicalId":672,"journal":{"name":"Journal of the American Society for Mass Spectrometry","volume":" ","pages":"236-240"},"PeriodicalIF":3.1,"publicationDate":"2025-02-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11808759/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142998181","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Gas-Phase Unfolding Reveals Stability Shifts Associated with Substrate Binding in Modular Polyketide Synthases.","authors":"Chunyi Zhao, Nicholas B Borotto, Jennifer Schmidt, Kinshuk Srivastava, Andrew Lowell, Kristina Hakansson, David H Sherman, Brandon T Ruotolo","doi":"10.1021/jasms.4c00179","DOIUrl":"10.1021/jasms.4c00179","url":null,"abstract":"<p><p>Native mass spectrometry (MS), ion mobility (IM), and collision-induced unfolding (CIU) have all been widely used to study the binding of small molecules to proteins and their complexes. Despite many successes in detecting subtle gas-phase stability differences in smaller systems dominated by single-domain subunits, studies targeting complexes comprised of large, multidomain subunits still face many challenges. For example, polyketide synthases (PKSs) are multiprotein enzymes that use their modular architecture to produce polyketide natural products and form the basis for nearly one-third of pharmaceuticals. Here, we describe the development of CIU methods capable of extracting information from these multiprotein complexes and demonstrate the current limits of quantitative CIU technology by probing the stabilities ∼280 kDa PKS dimer protein complexes. Our approach detects the evidence of the stability shifts associated with substrate binding that accounts for <0.1% of the mass for the intact assembly.</p>","PeriodicalId":672,"journal":{"name":"Journal of the American Society for Mass Spectrometry","volume":" ","pages":"241-246"},"PeriodicalIF":3.1,"publicationDate":"2025-02-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141756491","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Efficient Coupling of Structures for Lossless Ion Manipulations with Ion Trap Mass Analyzers Using Phase Modulation.","authors":"Nathan W Buzitis, Brian H Clowers","doi":"10.1021/jasms.4c00490","DOIUrl":"10.1021/jasms.4c00490","url":null,"abstract":"<p><p>Phased structures for lossless ion manipulation offer significant improvements over the scanning second gate method for coupling with ion trap mass analyzers. With an experimental run time of under 1 min for select conditions and an average run time of less than 4 min, this approach significantly reduces experimental time while enhancing the temporal duty cycle. The outlined SLIM system connects to an ion trap mass analyzer via a PCB stacked ring ion guide, which replaces the commercial ion optics and capillary inlet. By applying a discrete and repeating injection pulse and solving a series of algebraic equations, the system reconstructs an arrival time distribution with a minimal degree of error with enhanced ion throughput. To demonstrate the feasibility of this approach, the 3.4-m SLIM system resolves gas-phase conformers for various small peptides and proteins. This system and methodology also enable direct implementation between SLIM and ion trap mass analyzers traditionally interfaced with front separation systems such as liquid chromatography.</p>","PeriodicalId":672,"journal":{"name":"Journal of the American Society for Mass Spectrometry","volume":" ","pages":"424-432"},"PeriodicalIF":3.1,"publicationDate":"2025-02-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142926190","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Gas-Phase Fragmentation of Coenzyme Q₁₀ Radical Anion Generated by APCI: A Study by High/Low-Resolution Tandem/Sequential Mass Spectrometry.","authors":"Mariachiara Bianco, Ilario Losito, Giovanni Ventura, Beniamino Leoni, Onofrio Davide Palmitessa, Massimiliano Renna, Pietro Santamaria, Cosima Damiana Calvano, Tommaso R I Cataldi","doi":"10.1021/jasms.4c00399","DOIUrl":"10.1021/jasms.4c00399","url":null,"abstract":"<p><p>Coenzyme Q₁₀ (CoQ₁₀) and closely related compounds with varying isoprenoid tail lengths (CoQ_<i>n</i>, <i>n</i> = 6-9) are biochemical cofactors involved in many physiological processes, playing important roles in cellular respiration and energy production. Liquid chromatography (LC) coupled with single or tandem mass spectrometry (MS) using electrospray (ESI) or atmospheric pressure chemical ionization (APCI) is considered the gold standard for the identification and quantification of CoQ₁₀ in food and biological samples. However, the characteristic fragmentation exhibited by the CoQ₁₀ radical anion ([M]^•^-, <i>m</i>/<i>z</i> 862.684), the prevailing ion generated by APCI in negative polarity, has not been studied in detail. In this work, a systematic study was carried out to clarify this issue, using higher collisional energy dissociation (HCD) with high-resolution tandem FTMS and collision-induced dissociation-low-resolution sequential mass spectrometry (CID-MS^<i>n</i>, <i>n</i> = 2-4). Various fragmentation pathways were successfully interpreted, with some structures proposed for product ions checked using density functional theory (DFT) calculations. Besides the already-known detachments of methyl radicals occurring directly from the CoQ₁₀ radical anion and leading to ions like [M - CH₃]<b>^-</b> and [M - 2CH₃]^•-, the homolytic cleavage of C-C bonds along the oligo-isoprenoid side chain was tentatively proposed to explain some of the observed fragmentations. As a result, the generation of uncommon yet potentially stable distonic biradical anions was hypothesized, with some of them likely undergoing intramolecular cyclization to generate ions without unpaired electrons. Diagnostic product ions emerged from the fragmentation processes of CoQ₁₀ and were found to be common also to the radical anions of other CoQ_<i>n</i> derivatives (<i>n</i> = 7-9), facilitating their identification in extracts of edible <i>Brassicaceae</i> plant microgreens by reversed-phase liquid chromatography (RPLC)-APCI-FTMS.</p>","PeriodicalId":672,"journal":{"name":"Journal of the American Society for Mass Spectrometry","volume":" ","pages":"318-328"},"PeriodicalIF":3.1,"publicationDate":"2025-02-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142998182","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Unexpected Artifact Formation in Mass Spectrometric Analysis of Aniline under Atmospheric-Pressure Chemical Ionization.","authors":"Ishira Samarasinghe, Julius Pavlov, Athula B Attygalle","doi":"10.1021/jasms.4c00286","DOIUrl":"https://doi.org/10.1021/jasms.4c00286","url":null,"abstract":"<p><p>Atmospheric-pressure chemical ionization mass spectrometry (APCI-MS) is a widely used technique for the analysis of a diverse range of analytes. Under APCI conditions, a nonthermal plasma, rich in highly oxidative species such as H₂O₂, O₃, atomic O, and radicals such as HO^•, is created. These oxidants trigger unanticipated and often undesirable chemical reactions within the ion source. For example, when aniline was introduced into this environment, it initially underwent oxidative dimerization forming hydrazobenzene (<i>m</i>/<i>z</i> 185). However, with prolonged exposure, there was a marked increase in total ion abundance and the generation of additional artifact ions such as protonated azobenzene (<i>m</i>/<i>z</i> 183) and protonated azoxybenzene (<i>m</i>/<i>z</i> 199). The emergence of these artifacts was found to be highly dependent on the corona-current magnitude. Moreover, the desorption-gas temperature significantly influenced the rate of artifact generation. Recognizing and acknowledging the formation and presence of such artifacts in an ion source is paramount in conducting validated chemical analysis. The existence of artifacts can complicate mass spectral interpretation, potentially leading to erroneous conclusions and misinterpretations of both qualitative and quantitative data. Thus, understanding the intricacies of nonthermal plasma-driven artifact formation is critical for accurate analytical outcomes.</p>","PeriodicalId":672,"journal":{"name":"Journal of the American Society for Mass Spectrometry","volume":" ","pages":""},"PeriodicalIF":3.1,"publicationDate":"2025-02-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143187895","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Faces of Mass Spectrometry/Jose Navarrete-Perea.","authors":"Anne Brenner, J D Brookbank","doi":"10.1021/jasms.5c00020","DOIUrl":"https://doi.org/10.1021/jasms.5c00020","url":null,"abstract":"","PeriodicalId":672,"journal":{"name":"Journal of the American Society for Mass Spectrometry","volume":" ","pages":""},"PeriodicalIF":3.1,"publicationDate":"2025-02-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143187892","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Improved LC-MS Detection of Opioids, Amphetamines, and Psychedelics Using TrEnDi.","authors":"Christian A Rosales, Noah A Lepinsky, Wondewossen Gebeyehu, Karl V Wasslen, Fraser Colquhoun, Benjamin B Warnes, Jasmine Chihabi, Jeffrey M Manthorpe, Jeffrey C Smith","doi":"10.1021/jasms.4c00382","DOIUrl":"https://doi.org/10.1021/jasms.4c00382","url":null,"abstract":"<p><p>Substances of misuse are becoming increasingly difficult to analyze as unique methods of smuggling are adopted and due to the rapid emergence of new psychoactive substances, increasing the pool of compounds to characterize and identify. Technologies such as gas chromatography and liquid chromatography coupled to mass spectrometry (MS) represent the gold standard for accurate and robust analysis, with on-site ambient- and portable-MS systems providing rapid methods of drug screening and testing. For many samples containing residual analyte quantities, methods to improve sensitivity through chemical derivatization are critical for accurate determination. Herein, we demonstrate for the first time the use of trimethylation enhancement using diazomethane (TrEnDi) to improve the MS-based sensitivity of 13 different drugs of misuse. All analytes were successfully permethylated, with 11 demonstrating improved analytical characteristics from TrEnDi with MS sensitivity enhancements ranging from 1.2-fold to as high as 24.2-fold in the case of psilocybin, as well as increases in reversed-phase chromatographic retention for most species. Derivatization using ¹³C-isotopically labeled TrEnDi reagents were used to successfully resolve isobaric interference issues between three pairs of controlled substances. By using an unconventional aprotic solvent system for electrospray ionization, the benefit of a fixed-permanent positive charge was highlighted as TrEnDi-modified amphetamine was easily measured while unmodified was not detected. Finally, TrEnDi was employed to boost the sensitivity of morphine in a real urine matrix. Our results demonstrate a percent recovery of 103.1% and a sensitivity enhancement of 2.4-fold, demonstrating the versatility and applicability of TrEnDi to pre-existing analytical workflows for trace analysis.</p>","PeriodicalId":672,"journal":{"name":"Journal of the American Society for Mass Spectrometry","volume":" ","pages":""},"PeriodicalIF":3.1,"publicationDate":"2025-02-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143078410","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}