scholarly journals The MALDI-TOF Mass Spectrometric View of the Plasma Proteome and Peptidome

2006 ◽  
Vol 52 (7) ◽  
pp. 1223-1237 ◽  
Author(s):  
Glen L Hortin
Keyword(s):  
Plasma Proteins ◽  
Early Stage ◽  
Laser Desorption ◽  
Laser Desorption Ionization ◽  
Maldi Tof Ms ◽  
Desorption Ionization ◽  
Maldi Tof ◽  
Small Proteins ◽  
Tof Ms ◽  
Proteins And Peptides

Abstract Background: Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) and the related technique, surface-enhanced laser desorption/ionization (SELDI)-TOF MS, are being applied widely to analyze serum or plasma specimens for potential disease markers. Methods: Reports on the basic principles and applications of MALDI-TOF MS were reviewed and related to information on abundance and masses of major plasma proteins. Outcomes: MALDI-TOF MS is a particle-counting method that responds to molar abundance, and ranking of plasma proteins by molar abundance increases the rank of small proteins relative to traditional ranking by mass abundance. Detectors for MALDI-TOF MS augment the bias for detecting smaller components by yielding stronger signals for an equivalent number of small vs large ions. Consequently, MALDI-TOF MS is a powerful tool for surveying small proteins and peptides comprising the peptidome or fragmentome, opening this new realm for analysis. It is complementary to techniques such as electrophoresis and HPLC, which have a bias for detecting larger molecules. Virtually all of the potential markers identified by MALDI-TOF MS to date represent forms of the most abundant plasma proteins. Conclusions: Analyses of serum or plasma by MALDI-TOF MS provide new information mainly about small proteins and peptides with high molar abundance. The spectrum of observed proteins and peptides suggests value for applications such as assessment of cardiovascular risk, nutritional status, liver injury, kidney failure, and systemic immune responses rather than early detection of cancer. Extending analysis by MALDI-TOF MS to lower abundance components, such as markers for early-stage cancers, probably will require more extensive specimen fractionation before analysis.

scholarly journals Assessment of Reproducibility of Matrix-Assisted Laser Desorption Ionization–Time of Flight Mass Spectrometry for Bacterial and Yeast Identification

2015 ◽  
Vol 53 (7) ◽  
pp. 2349-2352 ◽  
Author(s):  
Lars F. Westblade ◽  
Omai B. Garner ◽  
Karen MacDonald ◽  
Constance Bradford ◽  
David H. Pincus ◽  
...  
Keyword(s):  
Laser Desorption ◽  
Laser Desorption Ionization ◽  
Ionization Time ◽  
Maldi Tof Ms ◽  
Microbial Identification ◽  
Desorption Ionization ◽  
Maldi Tof ◽  
Tof Ms ◽  
Matrix Assisted Laser ◽  
Matrix Assisted Laser Desorption

Matrix-assisted laser desorption ionization–time of flight (MALDI-TOF) mass spectrometry (MS) has revolutionized the identification of clinical bacterial and yeast isolates. However, data describing the reproducibility of MALDI-TOF MS for microbial identification are scarce. In this study, we show that MALDI-TOF MS-based microbial identification is highly reproducible and can tolerate numerous variables, including differences in testing environments, instruments, operators, reagent lots, and sample positioning patterns. Finally, we reveal that samples of bacterial and yeast isolates prepared for MALDI-TOF MS identification can be repeatedly analyzed without compromising organism identification.

scholarly journals Matrix-Assisted Laser Desorption Ionization–Time of Flight (MALDI-TOF) Mass Spectrometry for Detection of Antibiotic Resistance Mechanisms: from Research to Routine Diagnosis

2013 ◽  
Vol 26 (1) ◽  
pp. 103-114 ◽  
Author(s):  
Jaroslav Hrabák ◽  
Eva Chudáčková ◽  
Radka Walková
Keyword(s):  
Antibiotic Resistance ◽  
Laser Desorption ◽  
Laser Desorption Ionization ◽  
Ionization Time ◽  
Maldi Tof Ms ◽  
Desorption Ionization ◽  
Maldi Tof ◽  
Tof Ms ◽  
Matrix Assisted Laser ◽  
Matrix Assisted Laser Desorption

SUMMARYMatrix-assisted laser desorption ionization–time of flight mass spectrometry (MALDI-TOF MS) has been successfully applied as an identification procedure in clinical microbiology and has been widely used in routine laboratory practice because of its economical and diagnostic benefits. The range of applications of MALDI-TOF MS has been growing constantly, from rapid species identification to labor-intensive proteomic studies of bacterial physiology. The purpose of this review is to summarize the contribution of the studies already performed with MALDI-TOF MS concerning antibiotic resistance and to analyze future perspectives in this field. We believe that current research should continue in four main directions, including the detection of antibiotic modifications by degrading enzymes, the detection of resistance mechanism determinants through proteomic studies of multiresistant bacteria, and the analysis of modifications of target sites, such as ribosomal methylation. The quantification of antibiotics is suggested as a new approach to study influx and efflux in bacterial cells. The results of the presented studies demonstrate that MALDI-TOF MS is a relevant tool for the detection of antibiotic resistance and opens new avenues for both clinical and experimental microbiology.

scholarly journals Effect of Culture Conditions on Microorganism Identification by Matrix-Assisted Laser Desorption Ionization Mass Spectrometry

2005 ◽  
Vol 71 (1) ◽  
pp. 58-64 ◽  
Author(s):  
Nancy Valentine ◽  
Sharon Wunschel ◽  
David Wunschel ◽  
Catherine Petersen ◽  
Karen Wahl
Keyword(s):  
Mass Spectrometry ◽  
Laser Desorption ◽  
Ionization Mass ◽  
Laser Desorption Ionization ◽  
Maldi Tof Ms ◽  
Desorption Ionization ◽  
Maldi Tof ◽  
Tof Ms ◽  
Matrix Assisted Laser ◽  
Matrix Assisted Laser Desorption

ABSTRACT Matrix-assisted laser desorption ionization-time-of-flight mass spectrometry (MALDI-TOF MS) has been used to identify bacteria based upon protein signatures. This research shows that while some different proteins are produced by vegetative bacteria when they are cultured in different growth media, positive identification with MALDI-TOF MS is still possible with the protocol established at the Pacific Northwest National Laboratory (K. H. Jarman, S. T. Cebula, A. J. Saenz, C. E. Petersen, N. B. Valentine, M. T. Kingsley, and K. L. Wahl, Anal. Chem. 72:1217-1223, 2000). A core set of small proteins remain constant under at least four different culture media conditions and blood agar plates, including minimal medium M9, rich media, tryptic soy broth (TSB) or Luria-Bertani (LB) broth, and blood agar plates, such that analysis of the intact cells by matrix-assisted laser desorption/ionization mass spectrometry allows for consistent identification.

scholarly journals Iodine-Assisted Laser Desorption/Ionization Time-of-Flight Mass Spectrometry

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Sai Raghuveer Chava
Keyword(s):  
Mass Spectrometry ◽  
Time Of Flight ◽  
Laser Desorption ◽  
Laser Desorption Ionization ◽  
Ionization Time ◽  
Maldi Tof Ms ◽  
Desorption Ionization ◽  
Maldi Tof ◽  
Flight Mass Spectrometry ◽  
Tof Ms

Adsorption and desorption of iodine-containing α-cyano-4-hydroxycinnamic acid (aCCa) matrix species were studied using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). The MALDI-TOF MS method showed that ca. 0.8- 1.4 monolayer (~ 100 ppm) of iodine-containing species was adsorbed at the surface and assisted in desorption and ionization of a protein digest peptides or peptides varying in isoelectric potential. At low laser power, desorption of analytes in protonated and sodiated form was observed but not iodine cluster relative to aCCa without iodine, suggesting a two-electron reduction process to form the protonated pseudo molecular ion, although adsorption on the surface would lead to oxidation of iodide to iodine. The addition of iodine to matrix has been demonstrated to greatly facilitate the MALDI-TOF MS process and is a valuable tool when complex protein mixtures need to be analyzed.

scholarly journals Differentiation of Brachyspira spp. isolated from laying hens using PCR-based methods and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry

2018 ◽  
Vol 30 (4) ◽  
pp. 545-553
Author(s):  
Monika Harms ◽  
Volker Schmidt ◽  
Tilo Heydel ◽  
Jutta Hauptmann ◽  
Christine Ahlers ◽  
...  
Keyword(s):  
Laser Desorption ◽  
Laser Desorption Ionization ◽  
Ionization Time ◽  
Maldi Tof Ms ◽  
Desorption Ionization ◽  
Maldi Tof ◽  
Flight Mass Spectrometry ◽  
Tof Ms ◽  
Matrix Assisted Laser ◽  
Matrix Assisted Laser Desorption

Avian intestinal spirochetosis (AIS), an important but neglected disease in laying hens, is caused by Brachyspira pilosicoli, B. intermedia, and B. alvinipulli. Poultry are also frequently colonized by putatively nonpathogenic species such as B. murdochii and B. innocens. We evaluated the differentiation of Brachyspira species by 3 methods: sequencing of the reduced nicotinamide adenine dinucleotide (NADH) oxidase gene ( nox), matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS), and a new multiplex (m)PCR targeting genes such as the tryptophanase A gene ( tnaA) and the p-aminobenzoyl-glutamate hydrolase subunit B gene ( abgB). Sequencing of 414 bp of the nox PCR amplification products generated from 41 pure cultures of avian Brachyspira isolates allowed presumptive species identification in 33 isolates with at least 99% identity in basic local alignment search tool analysis, including B. pilosicoli, B. intermedia, B. murdochii, B. innocens, and “ B. pulli”. MALDI-TOF MS analysis was found to be a reliable tool for differentiation after extension of the manufacturer’s database. In the mPCR, all isolates identified as B. pilosicoli and B. intermedia were positive for abgB and tnaA, respectively. The mPCR might be very useful in detecting Brachyspira species in mixed cultures including not only nonpathogenic species, such as B. innocens, but also one of the AIS pathogens. We found that MALDI-TOF MS analysis combined with the mPCR targeting tnaA and abgB was suitable for the identification of avian isolates of B. pilosicoli and B. intermedia, 2 important agents of AIS.

Caracterización por Espectrometría de Masas MALDI de Cucurbit[n]uriles (n = 6,7,8)

1969 ◽  
Vol 3 (2) ◽  
Author(s):  
María Emilia Dueñas ◽  
Sebastián Manzano ◽  
Vanessa Jiménez ◽  
Cesar H. Zambrano ◽  
Cristian Santacruz ◽  
...  
Keyword(s):  
Laser Desorption ◽  
Laser Desorption Ionization ◽  
Maldi Tof Ms ◽  
Maldi Matrix ◽  
Desorption Ionization ◽  
Maldi Tof ◽  
Tof Ms ◽  
Matrix Assisted Laser ◽  
Matrix Assisted Laser Desorption

La caracterización de una mezcla de cucurbit[n]uriles (n = 6,7,8) se ha realizado por medio de espectrometría de masas con la técnica de ionización MALDI (Matrix-assisted Laser Desorption/Ionization). Los cucurbit[n]uriles fueron sintetizados como parte de una investigación de química supramolecular dentro del Departamento de Química e Ingeniería Química de la USFQ. Para el análisis con MALDI se ha introducido un procedimiento adecuado para la preparación de muestras, que incluye la disolución efectiva de la mezcla sólida de cucurbit[n]uriles en una solución de agua y ácido fórmico, y el uso del ácido alfa-ciano-4-hidroxi-cinámico como matriz MALDI, en una solución 10g/l en 70:30 (v:v) de metanol y acetronitrilo. En el proceso de preparación de muestras para MALDI se intentó utilizar otros solventes para el cucurbit[n]uril con pobres resultados. La adición del ácido fórmico al agua desionizada fue importante para lograr la correcta disolución del compuesto y asegurar su compatibilidad con la solución de matriz. Para obtener los espectros de masas correspondientes se utilizó un espectrómetro de masas de tiempo de vuelo MALDI (MALDI TOF-MS) construido en el Departamento de Física de la EPN. Los espectros de masa de los cucurbit[n]uriles se caracterizaron por la presencia de los iones protonados con una carga de las especies moleculares correspondientes a n = 6,7,8, según se infiere de los valores m/z medidos. Adicionalmente, los espectros de masa contuvieron picos abundantes de la matriz MALDI en la región de masas hasta 500 Da. Los espectros de masa se calibraron internamente de forma satisfactoria con la ayuda de os múltiples picos del polímero PEG600 que se introdujo como un estándar interno en las muestras. La resolución de masas instrumental permitió separar las componentes isotópicas a lo largo de todo el rango de masas y una precisión general en la detrminación de la masa de alrededor de 0.1 %. La señal más intensa entre los cucurbit[n]uriles se la asignó al compuesto cucurbit[7]uril. Se hace una corta discusión tendiente a racionalizar la observación de las especies observadas con nuestra metodología experimental.

scholarly journals Identification of clinical dermatophyte isolates obtained from Iran by matrix-assisted laser desorption/ionization time-offlight mass spectrometry

2019 ◽  
Author(s):  
Mohammad Taghi Hedayati ◽  
Saham Ansari ◽  
Bahram Ahmadi ◽  
Mojtaba Taghizadeh Armaki ◽  
Tahereh Shokohi ◽  
...  
Keyword(s):  
Laser Desorption ◽  
Laser Desorption Ionization ◽  
Ionization Time ◽  
Maldi Tof Ms ◽  
Desorption Ionization ◽  
Maldi Tof ◽  
Protein Spectra ◽  
Tof Ms ◽  
Matrix Assisted Laser ◽  
Matrix Assisted Laser Desorption

Background and Purpose: Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) is widely used to discriminate among pathogenic microorganisms in clinical laboratories. The aim of this study was to assess the utility of MALDI-TOF MS in the routine identification of clinical dermatophyte isolates obtained from various geographical regions of Iran. Materials and Methods: A total of 94 isolates, including Trichophyton interdigitale (n=44), T. rubrum (n=40), T. tonsurans (n=4), Microsporum canis (n=4), and Epidermophyton floccosum (n=1), were analyzed in this study. The identity of each isolate was determined by polymerase chani reaction amplification and sequencing of the internal transcribed spacer (ITS) region of nuclear-encoded ribosomal DNA and also MALDI-TOF MS. The obtained data by molecular approach were compared with MALDI-TOF MS. Results: The MALDI-TOF MS led to the identification of 44 (47%) isolates at the species level by generating the spectral score values of ≥ 2.0. However, there was not sufficient agreement between the results of the molecular-based ITS identification methods and MALDI-TOF MS in the species identification of 16 (17%) isolates. The Bruker Daltonics database was also not able to identify protein spectra related to 12 isolates (13%), including T. interdigitale (n=5), T. rubrum (n=4), M. canis (n=2), and T. tonsurans (n=1). Conclusion: According to the results, the utility of MALDI-TOF MS as a routine diagnostic tool for the accurate and reliable identification of dermatophytes can be justified whenever the protein spectra of a large set of worldwide clinical isolates are included in the commercial libraries. In addition, MALDI-TOF MS can be alternatively used to construct an in-house reference database.

scholarly journals Proteomic changes in bacteria caused by exposure to environmental conditions can be detected by Matrix-Assisted Laser Desorption/Ionization – Time of Flight (MALDI-ToF) Mass Spectrometry

2020 ◽  
Author(s):  
Denise Chac ◽  
Melissa Kordahi ◽  
Leandra Brettner ◽  
Arushi Verma ◽  
Paul McCleary ◽  
...  
Keyword(s):  
Laser Desorption ◽  
Laser Desorption Ionization ◽  
Ionization Time ◽  
Maldi Tof Ms ◽  
Phenotypic Differences ◽  
Desorption Ionization ◽  
Maldi Tof ◽  
Tof Ms ◽  
Matrix Assisted Laser ◽  
Matrix Assisted Laser Desorption

ABSTRACTIn the past decade, matrix-assisted laser desorption/ionization time-of-flight (MALDI-ToF) mass spectrometry (MS) has become a timely and cost-effective alternative to bacterial identification. The MALDI-ToF MS technique analyzes the total protein of culturable microorganisms at the species level and produces a mass spectra based on peptides which is compared to a database of identified profiles. Consequently, unique signatures of each microorganism are produced allowing identification at the species and, more importantly, strain level. Our present study proposes that the MALDI-ToF MS can be further used to screen functional and metabolic differences. While other studies applied the MALDI-ToF technique to identify subgroups within species, we investigated how various environmental factors could alter the unique bacterial signatures. We found that genetic and phenotypic differences between microorganisms belonging to the same species can be reflected in peptide-mass fingerprints generated by MALDI-ToF MS. These results suggest that MALDI-ToF MS can screen intra-species phenotypic differences of several microorganisms.

scholarly journals Hybrid CuCoO–GO enables ultrasensitive detection of antibiotics with enhanced laser desorption/ionization at nano-interfaces

2019 ◽  
Vol 10 (1) ◽  
pp. 257-267 ◽  
Author(s):  
Enhui Wu ◽  
Kun Feng ◽  
Rui Shi ◽  
Rui Lv ◽  
Fuzhong Ouyang ◽  
...  
Keyword(s):  
Laser Desorption ◽  
Sensitive Detection ◽  
Ultrasensitive Detection ◽  
Laser Desorption Ionization ◽  
Maldi Tof Ms ◽  
Desorption Ionization ◽  
Maldi Tof ◽  
Tof Ms

A hybrid CuCoO–GO matrix allows for sensitive detection of various antibiotics in combination with MALDI TOF MS.

scholarly journals Microbial Typing by Matrix-Assisted Laser Desorption Ionization–Time of Flight Mass Spectrometry: Do We Need Guidance for Data Interpretation?

2014 ◽  
Vol 53 (3) ◽  
pp. 760-765 ◽  
Author(s):  
Sébastien Spinali ◽  
Alex van Belkum ◽  
Richard V. Goering ◽  
Victoria Girard ◽  
Martin Welker ◽  
...  
Keyword(s):  
Laser Desorption ◽  
Laser Desorption Ionization ◽  
Ionization Time ◽  
Maldi Tof Ms ◽  
Desorption Ionization ◽  
Maldi Tof ◽  
Flight Mass Spectrometry ◽  
Tof Ms ◽  
Matrix Assisted Laser ◽  
Matrix Assisted Laser Desorption

The integration of matrix-assisted laser desorption ionization–time of flight mass spectrometry (MALDI-TOF MS) in clinical microbiology has revolutionized species identification of bacteria, yeasts, and molds. However, beyond straightforward identification, the method has also been suggested to have the potential for subspecies-level or even type-level epidemiological analyses. This minireview explores MALDI-TOF MS-based typing, which has already been performed on many clinically relevant species. We discuss the limits of the method's resolution and we suggest interpretative criteria allowing valid comparison of strain-specific data. We conclude that guidelines for MALDI-TOF MS-based typing can be developed along the same lines as those used for the interpretation of data from pulsed-field gel electrophoresis (PFGE).

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