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Protein profiling analysis based on matrix-assisted laser desorption/ionization-Fourier transform ion cyclotron resonance mass spectrometry and its application in typing Streptomyces isolates
摘要： Marine Streptomyces is a potential source of novel bioactive natural products in medicine and agriculture. The current discrimination and screening method of Streptomyces isolates is not accurate and time-consuming, and a novel method is necessary. In this study, a protein profiling method based on an ultrahigh resolution 15 Tesla Matrix-assisted laser desorption/ionization-Fourier transform ion cyclotron resonance mass spectrometry (MALDI-FTICR MS) was established and applied for differentiation and bioactivity screening of marine Streptomyces isolates. To obtain robust protein profiling, the effects of the protein extraction method, the matrix-solvent, the sample deposition mode, and the culture time of isolates on protein profiling were thoroughly studied, the optimal conditions were obtained. To evaluate the performance of the developed MALDI-FTICR MS method, MALDI-time of flight (TOF) MS and 16S rRNA were applied in parallel to analyze 25 marine Streptomyces isolates. We found that the clustering result of MALDI-FTICR MS was more similar to that of 16S rRNA than MALDI-TOF MS. And MALDI-FTICR MS could effectively indicate the antibacterial activity of Streptomyces isolates against three plant pathogenic bacteria including Xanthomonas campestris, Xanthomonas oryzae and Erwinia carotovora. Furthermore, a differential protein/peptide was defined and successfully applied to predict antibacterial activity of blind samples. This study demonstrated that MALDI-FTICR MS has great potential to discriminate and screen complex microorganisms, especially those closely related strains.
关键词： Protein profiling,Streptomyces isolates,Cluster analysis,Activity screening,Matrix-assisted laser desorption/ionization Fourier transform ion cyclotron resonance mass spectrometry
更新于2025-09-16 10:30:52
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[IEEE 2019 41st Annual International Conference of the IEEE Engineering in Medicine & Biology Society (EMBC) - Berlin, Germany (2019.7.23-2019.7.27)] 2019 41st Annual International Conference of the IEEE Engineering in Medicine and Biology Society (EMBC) - Towards OCT-Navigated Tissue Ablation with a Picosecond Infrared Laser (PIRL) and Mass-Spectrometric Analysis
摘要： Medical lasers are commonly used in interventions to ablate tumor tissue. Recently, the picosecond infrared laser has been introduced, which greatly decreases damaging of surrounding healthy tissue. Further, its ablation plume contains intact biomolecules which can be collected and analyzed by mass spectrometry. This allows for a specific characterization of the tissue. For a precise treatment, however, a suitable guidance is needed. Further, spatial information is required if the tissue is to be characterized at different parts in the ablated area. Therefore, we propose a system which employs optical coherence tomography as the guiding imaging modality. We describe a prototypical system which provides automatic ablation of areas defined in the image data. For this purpose, we use a calibration with a robot which drives the laser fiber and collects the arising plume. We demonstrate our system on porcine tissue samples.
关键词： optical coherence tomography,tissue ablation,mass spectrometry,robot calibration,picosecond infrared laser
更新于2025-09-16 10:30:52
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Distribution of Flavan-3-ol Species in Ripe Strawberry Fruit Revealed by Matrix-Assisted Laser Desorption/Ionization-Mass Spectrometry Imaging
摘要： Flavan-3-ols, which comprise proanthocyanidins and their monomers, are major ?avonoids in strawberries, and they have a wide range of biological activities and health bene?ts. However, their spatial distribution in strawberry fruit remains poorly understood. Therefore, we performed matrix-assisted laser desorption/ionization-mass spectrometry imaging (MALDI-MSI), to visualize ? ?avan-3-ols in ripe strawberry fruit. Peaks matching the m/z values of ?avan-3-ols [M ? H] ions were detected in the negative ion mode using 1,5-diaminonaphthalene as matrix. Catechin and/or epicatechin, three B-type procyanidins, and two B-type propelargonidins were identi?ed by MALDI-tandem MS. These ?avan-3-ols were mainly distributed in the calyx, in and around the vascular bundles, and in the skin. In-source fragmentation of proanthocyanidins was determined using their standards, suggesting their distribution was mixed ion images of themselves, and fragment ions generated from those had a higher degree of polymerization. B-type procyanidins were predominantly distributed in the vascular bundles than in the skin, whereas B-type propelargonidins were almost equally distributed between the vascular bundles and skin, suggesting that their distribution patterns are di?erent from the type of their ?avan-3-ol monomers. Flavan-3-ols, especially B-type procyanidins, may help prevent pathogen infection not only in the skin but also in and around the vascular bundles.
关键词： mass spectrometry imaging (MSI),propelargonidins,procyanidins,proanthocyanidins,?avan-3-ols,strawberry,matrix-assisted laser desorption/ionization (MALDI)
更新于2025-09-16 10:30:52
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Performances of ionic liquid matrices with butyl ammonium counterion for matrix-assisted laser desorption/ionization mass spectrometric detection and analysis of sucralfate
摘要： In this work, the performances of two ionic liquid matrices (ILMs) with the same ammonium counterpart for mass spectrometric analysis of the insoluble and soluble sucralfate were compared. Matrix-assisted laser desorption/ionization mass spectrometry (MALDI MS) was performed assisted by the butylammonium salts of a-cyano-hydroxycinnamic acid (CHCAB) and 2,5-dihydroxybenzoic acid (DHBB). CHCAB has a higher IE than DHBB, but better optical properties. CHCAB is more suitable for the analysis of sucralfate, although molecular ions of both compounds were detectable only with low intensities. Thus, optical properties of ILMs are crucial to enhance the sensitivity of MALDI MS detection of polysulfated oligosaccharides.
关键词： sucralfate,a-cyano-hydroxycinnamic acid,Ionic liquid matrices,2,5-dihydroxybenzoic acid,matrix-assisted laser desorption/ionization time-of-flight mass spectrometry
更新于2025-09-16 10:30:52
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Anti-Myocardial Infarction Effects of Radix Aconiti Lateralis Preparata Extracts and Their Influence on Small Molecules in the Heart Using Matrix-Assisted Laser Desorption/Ionization–Mass Spectrometry Imaging
摘要： Radix Aconiti Lateralis Preparata (fuzi) is the processed product of Aconitum carmichaelii Debeaux tuber, and has great potential anti-myocardial infarction e?ects, including improving myocardial damage and energy metabolism in rats. However, the e?ects of Radix Aconiti Lateralis Preparata extracts in a rat model of myocardial infarction have not yet been fully illustrated. Herein, Radix Aconiti Lateral Preparata was used to prepare Radix Aconiti Lateralis Preparata extract (RAE), fuzi polysaccharides (FPS), and fuzi total alkaloid (FTA). Then, we aimed to compare the e?ects of RAE, FPS, and FTA in MI rats and further explore their in?uence on small molecules in the heart. We reported that Radix Aconiti Lateralis Preparata extract (RAE) and fuzi total alkaloid (FTA) signi?cantly improved left ventricular function and structure, and reduced myocardial damage and infarct size in rats with myocardial infarction by the left anterior descending artery ligation. In contrast, fuzi polysaccharides (FPS) was less e?ective than RAE and FTA, indicating that alkaloids might play a major role in the treatment of myocardial infarction. Moreover, via matrix-assisted laser desorption/ionization–mass spectrometry imaging (MALDI–MSI), we further showed that RAE and FTA containing alkaloids as the main common components regulated myocardial energy metabolism-related molecules and phospholipids levels and distribution patterns against myocardial infarction. In particular, it was FTA, not RAE, that could also regulate potassium ions and glutamine to play a cardioprotective role in myocardial infarction, which revealed that an appropriate dose of alkaloids generated more obvious cardiotonic e?ects. These ?ndings together suggested that Radix Aconiti Lateralis Preparata extracts containing an appropriate dose of alkaloids as its main pharmacological active components exerted protective e?ects against myocardial infarction by improving myocardial energy metabolism abnormalities and changing phospholipids levels and distribution patterns to stabilize the cardiomyocyte membrane structure. Thus, RAE and FTA extracted from Radix Aconiti Lateralis Preparata are potential candidates for the treatment of myocardial infarction.
关键词： myocardial infarction,left anterior descending artery ligation,phospholipid,energy metabolism,matrix-assisted laser desorption/ionization–mass spectrometry imaging,Radix Aconiti Lateralis Preparata
更新于2025-09-16 10:30:52
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Water-assisted laser desorption/ionization mass spectrometry for minimally invasive in vivo and real-time surface analysis using SpiderMass
摘要： Rapid, sensitive, precise and accurate analysis of samples in their native in vivo environment is critical to better decipher physiological and physiopathological mechanisms. SpiderMass is an ambient mass spectrometry (MS) system designed for mobile in vivo and real-time surface analyses of biological tissues. The system uses a fibered laser, which is tuned to excite the most intense vibrational band of water, resulting in a process termed water-assisted laser desorption/ionization (WALDI). The water molecules act as an endogenous matrix in a matrix-assisted laser desorption ionization (MALDI)-like scenario, leading to the desorption/ionization of biomolecules (lipids, metabolites and proteins). The ejected material is transferred to the mass spectrometer through an atmospheric interface and a transfer line that is several meters long. Here, we formulate a three-stage procedure that includes (i) a laser system setup coupled to a Waters Q-TOF or Thermo Fisher Q Exactive mass analyzer, (ii) analysis of specimens and (iii) data processing. We also describe the optimal setup for the analysis of cell cultures, fresh-frozen tissue sections and in vivo experiments on skin. With proper optimization, the system can be used for a variety of different targets and applications. The entire procedure takes 1–2 d for complex samples.
关键词： mass spectrometry,SpiderMass,real-time surface analysis,Water-assisted laser desorption/ionization,in vivo analysis
更新于2025-09-16 10:30:52
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[IEEE 2019 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC) - Munich, Germany (2019.6.23-2019.6.27)] 2019 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC) - A Hyperspectral Microscope Based on a Birefringent Ultrastable Common-Path Interferometer
摘要： Spectral microscopy is a method to acquire the spectrum for each point in the image of a sample. The most straightforward technique uses spectral filters to collect a sequence of images at a discrete number of spectral bands. A more complete spectral characterization is hyperspectral microscopy, which acquires the whole continuous spectrum of each point of the image. A powerful approach to this aim is Fourier-transform (FT) spectrometry [1, 2], in which an optical waveform is split by an interferometer in two delayed replicas, whose interference pattern is measured by a detector as a function of their delay. The FT of the resulting interferogram yields the continuous intensity spectrum of the waveform. The FT approach is able to retrieve in parallel the spectra for all pixels in a scene and is hence suited for wide-field microscopy, but it requires controlling the delay with sub-cycle precision, which is very difficult to achieve with Michelson and Mach-Zehnder interferometers. Here we introduce a hyperspectral microscope based on the FT approach and using a compact, highly stable common-path birefringent interferometer, a version of the Translating-Wedge-based Identical pulses eNcoding System (TWINS) [3, 4]. Figure 1(a) shows the schematic setup of the microscope. Light is collected by an infinity-corrected objective, it propagates in the interferometer and it is imaged on the 2D detector (14-bits, silicon monochrome CMOS camera) by a tube lens. The component P1 polarizes the input light at 45°. A and B are (cid:302)BBO-birefringent blocks with crossed optical axes; block A is shaped in the form of two wedges, so that its total thickness can be changed by translating one of the wedges with a motorized stage. During propagation, the ordinary and extraordinary light projections accumulate a relative delay ranging from positive to negative values according to the relative thickness of A and B. P2 projects the replicas to the same polarization (45°), enabling interference. The spectral resolution of the interferometer is inversely proportional to the adjustable total phase delay. The largest position scan of our interferometer setup introduces a delay of ±250 fs at (cid:540) = 600 nm and corresponds to spectral resolution of 3 THz (~4 nm).
关键词： Fourier-transform spectrometry,TWINS,hyperspectral microscopy,birefringent interferometer
更新于2025-09-12 10:27:22
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Chemical analysis of a lunar meteorite by laser ablation mass spectrometry
摘要： The lunar meteorite Sayh al Uhaymir 169, that contains KREEP rich material, was investigated with our miniature laser ablation time-of-flight mass spectrometer to simulate the expected performance of in-situ measurements on the surface of a planetary body. The abundances of the major elements on the KREEP part of the rock were measured and plotted on a two-dimensional surface map to identify different mineral phases in the sample. The element distribution maps reveal the grain boundaries and allow identification of individual minerals and their major and trace element compositions. In the second measurement campaign the instrument was coupled with a HV pulser to increase sensitivity of the measurements. It could be shown that the detection sensitivity for heavy trace elements can be significantly improved while removing light elements from the analyzed ion beam. This study provides also measurements of U, Th and Pb elements present inside a single zircon grain. With the abundances of U and Pb in the zircon grain a preliminary age estimation of the zircon could be made and was found to be in reasonable agreement with ages reported in literature. Moreover, from the Ti concentration in the zircon grain a crystallization temperature was derived. Thus, by employing such an instrument on a planetary surface, scientific useful in-situ measurements on the element composition, the mineralogy, petrology and dating of surface samples can be accomplished.
关键词： Lunar meteorite,Trace elements,Laser ablation mass spectrometry,Crystallization temperature,KREEP material,Zircon
更新于2025-09-12 10:27:22
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[ACS Symposium Series] Fundamentals and Applications of Phosphorus Nanomaterials Volume 1333 || Phosphorus Clusters and Quantum Dots
摘要： Cluster is characterized by its unique role in chemistry and physics due to the fact that it bridges isolated atoms and bulk counterparts. It is also found that the structures and properties of clusters change dramatically with their sizes. Characterized by its diverse bonding patterns, phosphorus clusters have attracted many interests in past years. With the help of laser ablation mass spectrometry and other relative technologies, many kinds of phosphorus clusters have been generated, identified and studied. Their structures and properties are also widely studied by theoretical calculations. This chapter reviews both experimental and theoretical progresses about phosphorus clusters and relative species. On the other hand, the phosphorus quantum dots have attracted a great deal of attention due to its unique structures, properties, and applications in recent years. A quick overview on this topic is also included in the chapter, in order to attract more interests from broad research fields and make a bridge across the cluster study and nanomaterials to benefit scientists in both fields.
关键词： theoretical calculations,laser ablation mass spectrometry,quantum dots,phosphorus clusters,nanomaterials
更新于2025-09-12 10:27:22
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Membrane‐type frizzled‐related protein regulates lipidome and transcription for photoreceptor function
摘要： Molecular decision-makers of photoreceptor (PRC) membrane organization and gene regulation are critical to understanding sight and retinal degenerations that lead to blindness. Using Mfrprd6 mice, which develop PRC degeneration, we uncovered that membrane-type frizzled-related protein (MFRP) participates in docosahexaenoic acid (DHA, 22:6) enrichment in a manner similar to adiponectin receptor 1 (AdipoR1). Untargeted imaging mass spectrometry demonstrates cell-specific reduction of phospholipids containing 22:6 and very long-chain polyunsaturated fatty acids (VLC-PUFAs) in Adipor1?/? and Mfrprd6 retinas. Gene expression of pro-inflammatory signaling pathways is increased and gene-encoding proteins for PRC function decrease in both mutants. Thus, we propose that both proteins are necessary for retinal lipidome membrane organization, visual function, and to the understanding of the early pathology of retinal degenerative diseases.
关键词： RPE cell,retinal degenerations,Adipor1,inflammatory signaling,VLC-PUFAs,matrix-assisted laser desorption/ionization imaging mass spectrometry (MALDI IMS)
更新于2025-09-12 10:27:22