质谱技术在免疫分子的结构研究中的应用

质谱技术用于生物大分子的研究具有直接、简单、快速、经济等优点。近十年来 ,基质辅助激光解吸质谱 (MALDI MS)和电喷雾质谱 (ESI MS)在免疫学领域的研究中作出了重要贡献。本文着重对抗原、抗体、抗原 抗体复合物、抗原决定簇等免疫分子结构的质谱研究作一评述。大体分为四方面内容 :免疫分子的分子量、翻译后修饰、异质性、构象变化的分析 ;质谱指纹图的取得和串联质谱测序 ;抗原 抗体复合物的证明 ;B 细胞表位和T 细胞表位序列的测定。这些研究结果对于理解免疫分子的免疫功能、对于疾病的早期诊断、对于发展新药和疫苗具有重要意义     

Preservation and detection of specific antibody—peptide complexes by matrix-assisted laser desorption ionization mass spectrometry

The direct detection of an antibody-peptide complex is reported by matrix-assisted laser desorption ionization mass spectrometry (MALDI-MS). Experimental conditions have been found in which specific, noncovalent interactions in solution are maintained throughout the sample preparation and ionization process. Mass measurements based on the ion signals for the intact antibody and 1:1 antibody-peptide complex reveal that specific noncovalent associations between a monoclonal antibody and a peptide, which comprises the determinant of the corresponding antigen, are maintained in the gas phase. These results support the wider application of MALDI-MS to studies of the structure and specificity of macromolecular complexes important to immune and other biological function.     

Recent developments in radioanaytical technologies for environmental investigations

Radiometric techniques, specifically underground gamma-ray spectrometry, have been recently widely applied in the analysis of short and medium-lived radionuclides in the environment. Long-lived radionuclides have been mostly analysed by Accelerator Mass Spectrometry and Inductively Coupled Plasma Mass Spectrometry. These developments have considerably improved the detection limits for analysis of radionuclides in the terrestrial and marine environments. They have also decreased required sample volumes so applications, which have not been possible before either because of sample size or required sensitivity, have become feasible. The recent developments are illustrated by applications of radiometric and mass spectrometry techniques in isotope hydrology and oceanography.     

Mass‐spectrometry‐based lipidomics

Lipids, which have a core function in energy storage, signalling and biofilm structures, play important roles in a variety of cellular processes because of the great diversity of their structural and physiochemical properties. Lipidomics is the large‐scale profiling and quantification of biogenic lipid molecules, the comprehensive study of their pathways and the interpretation of their physiological significance based on analytical chemistry and statistical analysis. Lipidomics will not only provide insight into the physiological functions of lipid molecules but will also provide an approach to discovering important biomarkers for diagnosis or treatment of human diseases. Mass‐spectrometry‐based analytical techniques are currently the most widely used and most effective tools for lipid profiling and quantification. In this review, the field of mass‐spectrometry‐based lipidomics was discussed. Recent progress in all essential steps in lipidomics was carefully discussed in this review, including lipid extraction strategies, separation techniques and mass‐spectrometry‐based analytical and quantitative methods in lipidomics. We also focused on novel resolution strategies for difficult problems in determining C=C bond positions in lipidomics. Finally, new technologies that were developed in recent years including single‐cell lipidomics, flux‐based lipidomics and multiomics technologies were also reviewed.     

基质辅助激光解吸电离质谱和电喷雾电离质谱在辣根过氧化物酶糖肽结构分析中的应用

糖链结构的质谱解析是今后糖蛋白分析中的重要研究内容,其中完整糖肽的分析,由于可以同时获得糖基化位点和对应糖链的结构信息,更具有重要意义和研究前景。本工作对质谱软电离技术在完整糖肽分析中的应用进行了研究,其中包括了基质辅助激光解吸电离(matrix-assisted laser desorption ionization, MALDI)和电喷雾电离(electrospray ionization, ESI)技术。通过平行使用两种串联质谱(tandem mass spectrometry, MS/MS)分析策略: MALDI-MS/MS和ESI-MS/MS对目标糖蛋白——辣根过氧化物酶进行分析,并讨论了其互补性。结果表明,MALDI和ESI技术各有优劣,结合串联质谱分析,可获得糖肽的糖链结构信息;两条路线互补使用,在揭示蛋白质糖基化修饰(位点和结构)的研究中十分必要。     

A mini-review of mass spectrometry using high-performance FTICR-MS methods

Structural characterization of macromolecules is currently delivering new insights into the behavior of individual molecules or molecular ensembles. Technological advances have made it possible to examine smaller and smaller amounts (down to single molecules) of larger and larger molecular systems. Mass spectrometry in particular is capable of the detailed study of extremely small quantities (down to a single molecule) of very large (biological) molecules. The advent of new ionization techniques such as electrospray and matrix-assisted laser desorption are mainly responsible for these advances. As a result, mass spectrometry has evolved into an enabling discipline that plays an increasingly important role in combinatorial chemistry, polymer science, biochemistry, medicine, environmental and marine science, and archaeology and conservation science. This paper will review a selection of methodological developments in the field of high-performance Fourier transform ion cyclotron resonance mass spectrometry for structural analysis of these macromolecules.     

The application of electrospray ionization coupled to ultrahigh resolution mass spectrometry for the molecular characterization of natural organic matter

Mass spectrometry has recently played a key role in the understanding of natural organic matter (NOM) by providing molecular-level details about its composition. NOM, a complex assemblage of organic molecules present in natural waters and soils/sediments, has the ability to bind and transport anthropogenic materials. An improved understanding of its composition is crucial in order to understand how pollutants interact with NOM and how NOM cycles through global carbon cycles. In the past, low-resolution (>3000) mass analyzers have offered some insights into the structure of NOM, but emerging ultrahigh resolution (>200,000) techniques such as electrospray ionization (ESI) coupled to Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR-MS) have significantly advanced our knowledge of NOM chemistry. Here, a review of the recent literature on the advancements of NOM characterization and the applications of mass spectrometry to this central task is presented. Various methods for the analysis and display of the extremely complex mass spectra, such as the van Krevelen diagram and Kendrick mass defect analysis, are discussed. We also review tandem mass spectrometry techniques employed to gain structural information about NOM components. Finally, we show how ESI-FT-ICR-MS has been applied to examine specific issues that are important to the NOM scientific community, such as NOM reactivity, transport and fate, degradation, and existence of components, which are indicators of NOM origin. In general, ultrahigh resolution provided by FT-ICR-MS is essential for the complete separation of the thousands of peaks present in the complex NOM mixture and will clearly lead to additional future advancements in the areas of aquatic, soil, and analytical chemistry.     

Mass spectrometry of the human pituitary proteome: identification of selected proteins

The field of proteomics involves the combined application of advanced separation techniques, mass spectrometry, and bioinformatics tools to characterize proteins in complex biological mixtures. Here we report the identification of nine proteins from the human pituitary proteome, using the proteomics approach. The pituitary proteins were separated by two-dimensional electrophoresis, and were visualized by silver staining. The proteins of interest were subjected to in-gel digestion with trypsin, and the masses of the resulting peptides were determined by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. This tryptic mass map was used to identify the proteins through a search of a protein-sequence database. The identified proteins include important hormones, and enzymes with various catalytic activities. These proteins will be used to construct a two-dimensional reference database of the human pituitary. This database will be employed to study changes in the pituitary proteome that are associated with the formation of pituitary tumors.     

Recent progress in mass spectrometry for inorganic analysis

Mass spectrometry for inorganic analysis was originally developed with an r.f. spark ion source, a double focussing Mattauch-Herzog mass spectrograph and photographic plate detection. Current equipment is roughly equivalent to that which became available more than 25 years ago, but considerable technological and methodological progress has been achieved recently. Ion bombardment developed into an interesting alternative ionisation method for solid samples. Secondary ion mass spectrometry (SIMS) is widely used for surface inorganic and organic analysis, and localised microanalysis. Other alternative excitation modes have been proposed more recently : the inductively coupled plasma, the hollow cathode discharge and the pulsed laser. The inductively coupled plasma source appears to be promising for the sensitive mass spectrometric analysis of solutions. The laser source is emerging as a viable alternative for the spark source in existing spectrometers because of its more reproducible operating characteristics and the localised nature of the laser-solid interaction. The pulsed laser has led to the development and commercialisation of sensitive microanalysers with a lateral resolution of 1–3 μm. These instruments make use of time-of-flight mass analysers.Advances in the measurement techniques and in the instrumentation are described and a few representative examples of state of the art performance are discussed. Examples are selected from the experience in our own laboratory with SSMS, SIMS with the ion microscope and laser microprobe mass analysis with the transmission type LAMMA instrument. They will be selected from the field of environmental analytical chemistry and from that of the analytical chemistry of pure industrially important materials.     

功能脂质组质谱分析

近年来,鉴于脂质在疾病发生发展过程中的重要作用,功能脂质组研究受到广泛关注.质谱技术是功能脂质组分析的主要手段,本文将介绍用于功能脂质组分析的质谱技术,概述国内功能脂质组质谱分析的研究进展,并提出问题和展望,以期可以在现有方法上进行改进提高,用以发现更多的功能脂质,进而用于发展疾病生物标志物及治疗靶标以及研究疾病机理等,并期待推进功能脂质组学研究的发展.     

Progress of laser ionization mass spectrometry for elemental analysis — A review of the past decade

Mass spectrometry using a laser ionization source has played a significant role in elemental analysis. Three types of techniques are widely used: high irradiance laser ionization mass spectrometry is capable of rapid determination of elements in solids; single particle mass spectrometry is a powerful tool for single particle characterization; and resonance ionization mass spectrometry is applied for isotope ratio measurements with high sensitivity and selectivity. In this review, the main features of the laser ablation process and plasma characterization by mass spectrometry are summarized. Applications of these three techniques for elemental analysis are discussed.     

Mass spectrometry based cellular phosphoinositides profiling and phospholipid analysis: A brief review

Phospholipids are key components of cellular membrane and signaling. Among cellular phospholipids, phosphoinositides, phosphorylated derivatives of phosphatidylinositol are important as a participant in essential metabolic processes in animals. However, due to its low abundance in cells and tissues, it is difficult to identify the composition of phosphoinositides. Recent advances in mass spectrometric techniques, combined with established separation methods, have allowed the rapid and sensitive detection and quantification of a variety of lipid species including phosphoinositides. In this mini review, we briefly introduce progress in profiling of cellular phosphoinositides using mass spectrometry. We also summarize current progress of matrices development for the analysis of cellular phospholipids using matrix-assisted laser desorption/ionization mass spectrometry. The phosphoinositides profiling and phospholipids imaging will help us to understand how they function in a biological system and will provide a powerful tool for elucidating the mechanism of diseases such as diabetes, cancer and neurodegenerative diseases. The investigation of cellular phospholipids including phosphoinositides using electrospray ionization mass spectrometry and matrix-assisted laser desorption/ionization mass spectrometry will suggest new insights on human diseases, and on clinical application through drug development of lipid related diseases.     

生物质谱

质谱已成为生物和生物化学研究的一个重要的分析工具，特别是在蛋白质组学研究的作用更显突出，它的分析速度、准确性和灵敏度都是传统分析技术所不可比拟的。主要介绍了两种近年来发展最为迅速、应用最为广泛的软离子化质谱技术：即基体辅助激光解吸离子化质谱（MALDI－MS）和电喷了子化质谱（ESI－MS）的原理、技术的最新进展，并简单介绍了它们在蛋白质和多肽分析中的应用。     

A discussion on mass resolution in secondary ion mass spectrometry

Mass resolution is a very important parameter for mass spectrometry. It is necessary to compare the mass resolution between the newly developed TOF-SIMS and the conventionally high-performance magnetic SIMS. However, the definitions of mass resolution for these two types of instruments are quite different. Whether it is possible to compare mass resolution and how to do such comparison is a challenge. This problem was raised officially during the 2012 ISO/TC 201 meeting at Tampa, Florida, the United States and the long-term cooperation with ISO started afterwards. The definition of mass resolution is one of the most important and fundamental problems for mass spectrometry and should attract significant attention. Here, some detail discussions on mass resolution as well as the related experimental studies in the past few years, including the collaborations with ISO/TC 201/SC6 and SC1 are summarized. This summary covers the common problem for almost all the current existing and still used definitions of mass resolution. A reasonable new definition for mass resolution considering the peak shape or resolution function has been proposed, which has also been confirmed by using experimental studies of the mass resolution comparison between TOF and magnetic SIMS. This study lays a foundation for the future mass resolution comparisons between different mass spectrometry.     

基于质谱技术识别脂质双键位置的研究进展

脂质在能量贮存和信号传递方面发挥着巨大作用,同时还是生物膜的主要组成成分。不饱和脂质双键位置不同,生理学意义和生物学功能会有很大差异,因此脂质双键位置的识别至关重要。质谱具有灵敏快速、准确度高等优势,已成为脂质结构研究的重要方法。近年来,不同原理的电离技术与选择性衍生反应迅速发展起来,与质谱相结合已广泛应用于多种脂质双键位置的识别。本文主要对这些新型质谱技术进行总结,并展望了其未来发展趋势。     

Structural characterization and regiochemical differentiation of <Emphasis Type="Italic">α</Emphasis>-cyanoethylindole isomers in the gas phase

Mass spectrometry and tandem mass spectrometry techniques have been used to study the gas phase ion chemistry of isomeric alpha-cyanoethylindoles obtained by photochemical reactions. Both the fragmentation reactions occurring in the ion source, as well as metastable decompositions produced by the molecular and selected fragment ions, have allowed us to structurally characterize and differentiate each isomer from the others. The experiments, carried out also on deuterium labeled analogs, have shown the role exerted by the alpha-cyanoethyl substituent and by its position at the indolic ring on gas phase reactions that resulted to be distinctive and selective for each isomer. Ab initio theoretical calculations have been used to evaluate the stability and chemico-physical properties of different ion structures.     

Conversion of methionine into homocysteic acid in heavily oxidized proteomics samples

Analysis of protein oxidation is necessary in numerous areas of biochemistry, including hydroxyl radical surface mapping, oxidative stress assays, and pharmaceutical stability testing. Mass spectrometry is one of the tools most often used to identify protein oxidation products, and previous studies have attempted to identify and characterize all of the major oxidation products detected by mass spectrometry for each amino acid residue. In this note, we present evidence that in heavily oxidized protein samples, such as those produced by hydroxyl radical surface mapping, a major oxidation product of methionine is homocysteic acid. The formation of homocysteic acid from methionine was previously unrecognized in other mass spectrometric analyses, and has important implications for the analysis of oxidized samples, as well as potential implications as to the functional consequences of methionine oxidation. Copyright © 2010 John Wiley & Sons, Ltd.     

Mass spectrometry based proteomic studies on viruses and hosts--a review

In terms of proteomic research in the 21st century, the realm of virology is still regarded as an enormous challenge mainly brought by three aspects, namely, studying on the complex proteome of the virus with unexpected variations, developing more accurate analytical techniques as well as understanding viral pathogenesis and virus–host interaction dynamics. Progresses in these areas will be helpful to vaccine design and antiviral drugs discovery. Mass spectrometry based proteomics have shown exceptional display of capabilities, not only precisely identifying viral and cellular proteins that are functionally, structurally, and dynamically changed upon virus infection, but also enabling us to detect important pathway proteins. In addition, many isolation and purification techniques and quantitative strategies in conjunction with MS can significantly improve the sensitivity of mass spectrometry for detecting low-abundant proteins, replenishing the stock of virus proteome and enlarging the protein–protein interaction maps. Nevertheless, only a small proportion of the infectious viruses in both of animal and plant have been studied using this approach. As more virus and host genomes are being sequenced, MS-based proteomics is becoming an indispensable tool for virology. In this paper, we provide a brief review of the current technologies and their applications in studying selected viruses and hosts.     

Analysis of food proteins and peptides by mass spectrometry-based techniques

Mass spectrometry has arguably become the core technology for the characterization of food proteins and peptides. The application of mass spectrometry-based techniques for the qualitative and quantitative analysis of the complex protein mixtures contained in most food preparations is playing a decisive role in the understanding of their nature, structure, functional properties and impact on human health. The application of mass spectrometry to protein analysis has been revolutionized in the recent years by the development of soft ionization techniques such as electrospray ionization and matrix assisted laser desorption/ionization, and by the introduction of multi-stage and ‘hybrid’ analyzers able to generate de novo amino acid sequence information. The interfacing of mass spectrometry with protein databases has resulted in entirely new possibilities of protein characterization, including the high sensitivity mapping (femtomole to attomole levels) of post-translational and other chemical modifications, protein conformations and protein–protein and protein–ligand interactions, and in general for proteomic studies, building up the core platform of modern proteomic science. MS-based strategies to food and nutrition proteomics are now capable to address a wide range of analytical questions which include issues related to food quality and safety, certification and traceability of (typical) products, and to the definition of the structure/function relationship of food proteins and peptides. These different aspects are necessarily interconnected and can be effectively understood and elucidated only by use of integrated, up-to-date analytical approaches. In this review, the main aspects of current and perspective applications of mass spectrometry and proteomic technologies to the structural characterization of food proteins are presented, with focus on issues related to their detection, identification, and quantification, relevant for their biochemical, technological and toxicological aspects.     

更深度的“照相”技术——质谱成像的发展与应用

质谱成像是质谱技术在发展过程中所衍生出的前沿性科研领域,是一种将质谱技术和影像可视化技术结合而成的高科技"拍照"手段。它可以在没有特异性标记的情况下,对小分子、多肽、蛋白质等目标分子进行分析,在利用质谱分析提供目标化合物的结构信息的同时,提供其空间分布和含量变化信息。该技术在生物医药、临床医学、病理学、生命科学研究等领域具有极大的应用前景。