Mass spectrometry最新文献_第9页

Structure and m/z of Singly Charged Even-Electron Fragment Ions in Organic Mass Spectrometry: "A Rule of Mass Shift" Revisited (Secondary Publication). 有机质谱中单电荷偶电子碎片离子的结构和m/z:“质量位移规则”重访(二次出版)。

Mass spectrometry Pub Date : 2019-01-01 Epub Date: 2019-11-25 DOI: 10.5702/massspectrometry.A0074

Hisao Nakata

{"title":"Structure and m/z of Singly Charged Even-Electron Fragment Ions in Organic Mass Spectrometry: \"A Rule of Mass Shift\" Revisited (Secondary Publication).","authors":"Hisao Nakata","doi":"10.5702/massspectrometry.A0074","DOIUrl":"https://doi.org/10.5702/massspectrometry.A0074","url":null,"abstract":"Typical modes of bond cleavages of organic compounds in mass spectrometry are briefly summarized. Although these fragmentation rules can be quite useful for interpreting mass spectra of simple compounds, application to structurally complex molecules that contain multiple hetero atoms such as nitrogen or oxygen becomes increasingly difficult, because the exact location of an unpaired electron or positive or negative charges becomes obscure in precursor ions. About a decade ago, we proposed \"a rule of mass shift,\" which correctly predicts the m/z for observed peaks corresponding to singly charged even-electron fragment ions. The basis of the rule postulates that ions observed as peaks in an ordinary mass spectrum should be sufficiently stable to survive during the flight path in a mass spectrometer. The important recognition is that each atom in a stable ion should be in an ordinary valence state, and no free valence should be allowed. Therefore, if the cleavage of a bond leads to an ion with an unstable structure, some structural changes must take place in order for the ion to be observed in the mass spectrum. Such structural changes can be the addition of hydrogen atom(s) and/or a proton for positive ions, and the addition of a hydrogen atom and/or the elimination of two hydrogen atoms in the case of negative ions. These required structural changes in each case are schematically depicted and discussed in detail. Two typical examples are shown, in which m/z's of the observed peaks are correctly predicted. The scope and limitations, as well as the significance of the rule for analyzing fragmentations in organic mass spectrometry are also discussed.","PeriodicalId":18243,"journal":{"name":"Mass spectrometry","volume":"8 1","pages":"A0074"},"PeriodicalIF":0.0,"publicationDate":"2019-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6920629/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"37603704","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Development of Software for the In-Depth Analysis of Protein Dynamics as Determined by MALDI Mass Spectrometry-Based Hydrogen/Deuterium Exchange. 基于MALDI质谱法测定的蛋白质动力学深度分析软件的开发。

Mass spectrometry Pub Date : 2019-01-01 Epub Date: 2020-02-14 DOI: 10.5702/massspectrometry.S0082

Tatsuya Yamamoto, Tohru Yamagaki, Honoo Satake

{"title":"Development of Software for the In-Depth Analysis of Protein Dynamics as Determined by MALDI Mass Spectrometry-Based Hydrogen/Deuterium Exchange.","authors":"Tatsuya Yamamoto, Tohru Yamagaki, Honoo Satake","doi":"10.5702/massspectrometry.S0082","DOIUrl":"https://doi.org/10.5702/massspectrometry.S0082","url":null,"abstract":"Hydrogen/deuterium exchange (HDX) coupled with pepsin digestion is useful for rapidly analyzing the kinetic properties of small amounts of protein. However, the analysis of HDX by matrix-assisted laser desorption/ionization (MALDI) mass spectrometry (MS) is time-consuming due to a lack of dedicated software. Currently available software programs mainly calculate average mass shifts, even though the isotopic distribution width contains information regarding multiple protein conformations. Moreover, HDX reaction samples are typically composed of peptides that contain various numbers of deuterium atoms, which also hinders the rapid and comprehensive analysis of protein dynamics. We report here on the development of a software program \"Scipas DX\" that can be used to automatically analyze the hydrogen-deuterium isotopic distribution in peaks in HDX spectra and calculate the average number of atoms exchanged, the average deuteration ratio, the abundance ratio for exchanged atoms, and their fitted spectra with a high degree of accuracy within a few minutes. Analysis of the abundance ratio for exchanged atoms of a model protein, adenylate kinase 1, using Scipas DX indicate that the local structure at residues 83-106 and 107-117 are in a slow equilibrium, suggesting that these regions adopt multiple conformations that are involved in the stability and in switching between the active and inactive forms. Furthermore, precise HDX kinetics of the average deuteration ratio both confirmed the known induced conformations of two regions (residues 46-75 and 131-165) that are responsible for ligand binding and verified the novel structural dynamics of residues 107-117 and 166-196 following ligand binding to ligand-binding pockets 1 and 2, respectively. Collectively, these results highlight the usefulness and versatility of Scipas DX in MALDI-MS HDX-based analyses of protein dynamics.","PeriodicalId":18243,"journal":{"name":"Mass spectrometry","volume":"8 2","pages":"S0082"},"PeriodicalIF":0.0,"publicationDate":"2019-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.5702/massspectrometry.S0082","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"38693903","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Identifying Double Bond Positions in Phospholipids Using Liquid Chromatography-Triple Quadrupole Tandem Mass Spectrometry Based on Oxygen Attachment Dissociation. 基于氧附着解离的液相色谱-三重四极杆串联质谱法鉴定磷脂中的双键位置。

Mass spectrometry Pub Date : 2019-01-01 Epub Date: 2020-01-22 DOI: 10.5702/massspectrometry.S0080

Hidenori Takahashi, Yuji Shimabukuro, Daiki Asakawa, Akihito Korenaga, Masaki Yamada, Shinichi Iwamoto, Motoi Wada, Koichi Tanaka

{"title":"Identifying Double Bond Positions in Phospholipids Using Liquid Chromatography-Triple Quadrupole Tandem Mass Spectrometry Based on Oxygen Attachment Dissociation.","authors":"Hidenori Takahashi, Yuji Shimabukuro, Daiki Asakawa, Akihito Korenaga, Masaki Yamada, Shinichi Iwamoto, Motoi Wada, Koichi Tanaka","doi":"10.5702/massspectrometry.S0080","DOIUrl":"https://doi.org/10.5702/massspectrometry.S0080","url":null,"abstract":"Lipids, a class of biomolecules, play a significant role in the physiological system. In this study, gas-phase hydroxyl radicals (OH·) and atomic oxygens (O) were introduced into the collision cell of a triple quadruple mass spectrometer (TQ-MS) to determine the positions of the double bond in unsaturated phospholipids. A microwave-driven compact plasma generator was used as the OH·/O source. The reaction between OH·/O and the precursor ions passing through the collision cell generates product ions that correspond to the double bond positions in the fatty acyl chain. This double bond position specific fragmentation process initiated by the attachment of OH·/O to the double bond of a fatty acyl chain is a characteristic of oxygen attachment dissociation (OAD). A TQ-MS incorporating OAD, in combination with liquid chromatography, permitted a high throughput analysis of the double bond positions in complex biomolecules. It is important to know the precise position of double bonds in lipids, since these molecules can have widely different functionalities based on the position of the double bonds. The assignment of double bond positions in a mixture of eight standard samples of phosphatidylcholines (phospholipids with choline head groups) with multiple saturated fatty acyl chains attached was successfully demonstrated.","PeriodicalId":18243,"journal":{"name":"Mass spectrometry","volume":"8 2","pages":"S0080"},"PeriodicalIF":0.0,"publicationDate":"2019-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7709886/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"38693901","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 3

Atmospheric Pressure Dark-Current Argon Discharge Ionization with Comparable Performance to Direct Analysis in Real Time Mass Spectrometry. 大气压暗电流氩放电电离与实时质谱直接分析性能相当。

Mass spectrometry Pub Date : 2019-01-01 Epub Date: 2019-10-25 DOI: 10.5702/massspectrometry.A0075

Kanako Sekimoto, Motoshi Sakakura, Hiroshi Hike, Takatomo Kawamukai, Teruhisa Shiota, Mitsuo Takayama

{"title":"Atmospheric Pressure Dark-Current Argon Discharge Ionization with Comparable Performance to Direct Analysis in Real Time Mass Spectrometry.","authors":"Kanako Sekimoto, Motoshi Sakakura, Hiroshi Hike, Takatomo Kawamukai, Teruhisa Shiota, Mitsuo Takayama","doi":"10.5702/massspectrometry.A0075","DOIUrl":"https://doi.org/10.5702/massspectrometry.A0075","url":null,"abstract":"Herein, a dark-current discharge state created by combining argon flow with a needle electrode in ambient air is described that has an ionization efficiency and mechanism comparable to those of conventional helium direct analysis in real time (DART), without requiring dopants and DART glow discharge. Using this method, polar compounds such as α-amino acids were ionized in the dark-current argon discharge via (de)protonation, molecular anion formation, fragmentation, (de)protonation with the attachment of oxygen, deprotonation with hydrogen loss and negative ion attachment. In contrast, nonpolar compounds (e.g., n-alkanes) were detected as positive ions via hydride abstraction and oxidation. Major background ions observed were H3O+(H2O) n , O2 ·+, O2 ·-(H2O) n and CO3 ·-. These results indicate that the present dark-current discharge efficiently generates resonance-state argon with an internal energy of ∼14.2 eV, higher than that of the well-known metastable state (∼11.6 eV). It is therefore suggested that ionization reactions occurring there can be attributed to the Penning ionization of atmospheric H2O and O2 by resonance-state argon, analogous to helium DART.","PeriodicalId":18243,"journal":{"name":"Mass spectrometry","volume":"8 1","pages":"A0075"},"PeriodicalIF":0.0,"publicationDate":"2019-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.5702/massspectrometry.A0075","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"37459830","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Influence of Solvent Composition and Surface Tension on the Signal Intensity of Amino Acids in Electrospray Ionization Mass Spectrometry. 溶剂组成和表面张力对电喷雾质谱分析中氨基酸信号强度的影响。

Mass spectrometry Pub Date : 2019-01-01 Epub Date: 2019-11-30 DOI: 10.5702/massspectrometry.A0077

Ami Kageyama Kaneshima, Akira Motoyama, Mitsuo Takayama

{"title":"Influence of Solvent Composition and Surface Tension on the Signal Intensity of Amino Acids in Electrospray Ionization Mass Spectrometry.","authors":"Ami Kageyama Kaneshima, Akira Motoyama, Mitsuo Takayama","doi":"10.5702/massspectrometry.A0077","DOIUrl":"https://doi.org/10.5702/massspectrometry.A0077","url":null,"abstract":"The influence of solvent composition and surface tension on the signal intensity of deprotonated molecules [M-H]- in electrospray ionization mass spectrometry (ESI MS) was evaluated using alanine (Ala), threonine (Thr) and phenylalanine (Phe), which have differing levels of hydrophobicity. The surface tension of the ESI solution was varied by changing the ratio of the organic solvents methanol (MeOH) and acetonitrile (MeCN) in water (H2O). In ESI MS, the signal intensity of all the amino acids was increased with decreasing surface tension for the two solutions, H2O/MeOH and H2O/MeCN. The use of H2O/MeCN was more favorable for achieving a strong signal for the analytes compared to H2O/MeOH. The smaller vaporization enthalpy of MeCN compared to MeOH was proposed as one of the most plausible explanation for this. The order of the signal intensity of amino acids was Phe>Thr>Ala, the same order as their hydrophobicity. It can be practically concluded that the use of solutions with lower surface tensions and lower vaporization enthalpies would result in higher signal intensities in ESI MS.","PeriodicalId":18243,"journal":{"name":"Mass spectrometry","volume":"8 1","pages":"A0077"},"PeriodicalIF":0.0,"publicationDate":"2019-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.5702/massspectrometry.A0077","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"37603705","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 5

Troubleshooting Carry-Over in the LC-MS Analysis of Biomolecules: The Case of Neuropeptide Y. 排除生物分子LC-MS分析中的残留:神经肽Y的案例。

Mass spectrometry Pub Date : 2019-01-01 Epub Date: 2020-02-26 DOI: 10.5702/massspectrometry.S0083

Tohru Yamagaki, Takashi Yamazaki

引用次数: 4

Measurement of the Spatial Distribution of S1P in Small Quantities of Tissues: Development and Application of a Highly Sensitive LC-MS/MS Method Combined with Laser Microdissection. 少量组织中S1P空间分布的测量:高灵敏度LC-MS/MS结合激光显微解剖方法的开发与应用。

Mass spectrometry Pub Date : 2019-01-01 Epub Date: 2019-02-14 DOI: 10.5702/massspectrometry.A0072

Jiao Wang, Kuniyuki Kano, Daisuke Saigusa, Junken Aoki

{"title":"Measurement of the Spatial Distribution of S1P in Small Quantities of Tissues: Development and Application of a Highly Sensitive LC-MS/MS Method Combined with Laser Microdissection.","authors":"Jiao Wang, Kuniyuki Kano, Daisuke Saigusa, Junken Aoki","doi":"10.5702/massspectrometry.A0072","DOIUrl":"https://doi.org/10.5702/massspectrometry.A0072","url":null,"abstract":"Sphingosine-1-phosphate (S1P) acts as an extracellular signaling molecule with diverse biological functions. Tissues appear to have an S1P gradient, which is functionally relevant in the biological significance of S1P, although its existence has not been measured directly. Here, we report a highly sensitive method to determine the distribution of S1P, using a column-switching LC-MS/MS system combined with laser microdissection (LMD). Column switching using narrow core Capcell Pak C18 analytical and trap columns with 0.3 mm inner diameter improved the performance of the LC-MS/MS system. The calibration curve of S1P showed good linearity (r>0.999) over the range of 0.05-10 nM (1-200 fmol/injection). The accuracy of the method was confirmed by measuring S1P-spiked laser microdissected mice tissue sections. To evaluate our S1P analytical method, we quantified S1P extracted from micro-dissected mouse brain and spleen. These results show that this method can measure low S1P concentrations and determine S1P distribution in tissue microenvironments.","PeriodicalId":18243,"journal":{"name":"Mass spectrometry","volume":"8 1","pages":"A0072"},"PeriodicalIF":0.0,"publicationDate":"2019-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.5702/massspectrometry.A0072","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"36999673","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 4

Proposal: Recommendation on Measuring and Providing Mass Spectra as Chemical Information of Organic Molecules (Secondary Publication). 提案:关于测量和提供质谱作为有机分子化学信息的建议(二次出版)。

Mass spectrometry Pub Date : 2019-01-01 Epub Date: 2019-10-25 DOI: 10.5702/massspectrometry.A0076

MassBank Database Committee The Mass Spectrometry Society Of Japan

{"title":"Proposal: Recommendation on Measuring and Providing Mass Spectra as Chemical Information of Organic Molecules (Secondary Publication).","authors":"MassBank Database Committee The Mass Spectrometry Society Of Japan","doi":"10.5702/massspectrometry.A0076","DOIUrl":"https://doi.org/10.5702/massspectrometry.A0076","url":null,"abstract":"INTRODUCTION Many of us have surely had the experience of measuring the mass spectrum of a substance with a speci c purpose in mind and then having struggled to ascertain as to what should be considered important during the analysis, and which mass spectrum should be used to represent the substance. e MassBank Database Committee of the Mass Spectrometry Society of Japan has been holding discussions since the summer of 2017 to propose a set of guidelines to answer such questions. On request, several members of the society have provided us with their opinions on these questions. is paper aims to provide speci c guidelines, based on our discussions and society member’s opinions, on the methods of measurement and the correct manner of representation of: (1) mass spectra with electron ionization (EI), which is widely used in the mass spectrometry of substances, and (2) product ion spectra, obtained by the combination of electrospray ionization (ESI), which is a so ionization, and tandem mass spectrometry (MS/MS), which analyzes product ions by a high resolving mass analyzer. We assume situations where researchers, technicians, undergraduate and graduate students measure mass spectra and submit them as experimental data that lead to conclusions in academic papers, or as supporting data for documentation. In order to provide unambiguous and reliable guidelines that incorporate the latest developments in the eld of mass spectrometry, we request the society members to submit their opinions to this committee (Mail address: msdb@mssj.jp).","PeriodicalId":18243,"journal":{"name":"Mass spectrometry","volume":"8 1","pages":"A0076"},"PeriodicalIF":0.0,"publicationDate":"2019-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.5702/massspectrometry.A0076","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"37591538","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

A Special Issue for the 2nd International Biological Mass Spectrometry (BMS) Symposium 2018 in Kyoto. 2018年第二届国际生物质谱(BMS)研讨会特刊。

Mass spectrometry Pub Date : 2019-01-01 Epub Date: 2020-02-05 DOI: 10.5702/massspectrometry.K0012

Chen Lee Chuin, Tohru Yamagaki

引用次数: 0

High-Temperature Liquid Chromatography and the Hyphenation with Mass Spectrometry Using High-Pressure Electrospray Ionization. 高温液相色谱及高压电喷雾电离联用质谱法。

Mass spectrometry Pub Date : 2019-01-01 Epub Date: 2019-08-26 DOI: 10.5702/massspectrometry.S0079

Lee Chuin Chen

引用次数: 6