Espectrometrí­a de Masas

Marta Vilaseca

Manager
Espectrometría de masas

Tel Oficina : +34 93 403 98 15

correo-e : marta.vilasecairbbarcelona.org

Introducción

La Unidad de Espectrometría de Masas del IRB Barcelona ha sido creada para ofrecer soporte científico-técnico a los investigadores del Instituto y a sus colaboradores. La naturaleza interdisciplinaria de la Espectrometría de Masas y las nuevas tecnologías disponibles actualmente han provocado una gran expansión en su papel en la biotecnología y la investigación biomédica.

Según la definición propuesta per John B. Fenn (creador de la ionización por electrospray para biomoléculas y Nobel Laurate 2002 en Química), “la Espectrometría de Masas” es el arte de medir átomos y moléculas para determinar su peso molecular. La información sobre la masa o peso es a veces suficiente, a menudo necesaria y siempre útil en la determinación de la identidad de las especies. Para practicar este arte se proporciona carga a las moléculas de interés, i.e, el analito, y a continuación se mide cómo responden las trayectorias de los iones resultantes en condiciones de vacío y bajo la influencia de campos eléctricos y magnéticos. Claramente, el sine qua non de esta metodología es la conversión de los analitos neutros a iones. Para especies pequeñas y simples, la ionización ocurre por choques en fase gas entre moléculas neutras y electrones, fotones u otros iones. En los últimos años, los esfuerzos de muchos investigadores han conducido a nuevas técnicas para producir iones de especies que eran demasiado grandes y complejas para ser vaporizadas sin descomposición.

La Unidad de Espectrometría de Masas es una plataforma de reciente creación, equipada con espectrómetros de alta resolución y exactitud, con técnicas de espectrometría de masas recientemente incorporadas, como la espectrometría de movilidad iónica combinada con la espectrometría tandem de alta resolución, la espectrometría de masas de resonancia de ión ciclotrón con Transformada de Fourier, la ECD (disociación por captación de electrones) y la IRMPD (disociación por infrarrojo multifotón). La plataforma está encarada a la identificación y caracterización de un amplio rango de especies biológicas, desde moléculas pequeñas hasta biomoléculas grandes (ej. proteínas intactas), así como al estudio sobre la conformación, biología estructural e interacciones no covalentes de estas biomoléculas y complejos. La unidad tiene también el objetivo de profundizar en el estudio de biomarcadores proteicos que pueden indicar la presencia y progresión de diferentes enfermedades y de su respuesta a los fármacos de nuevo diseño.

La Unidad de Espectrometría de Masas tiene en sus planes de desarrollo colaborar estrechamente con la comunidad científica del IRB, combinando el amplio potencial de las nuevas técnicas en Espectrometría de Masas dentro de las ciencias de la vida, con la investigación estructural y biológica que se está llevando a cabo en el IRB y ser un valor añadido importante dentro de esta sinergia.

Para más información, por favor contacten con el especialista en Espectrometría de Masas en marta.vilasecairbbarcelona.org

Más información

• Mass Spectrometry Request Form
• 2008 Scientific Report - Mass Spectrometry Core Facility
• 2007 Scientific Report - Mass Spectrometry Core Facility

Espectrometrí­a de Masas

The services offered include MS, MS/MS and MSn analysis using atmospheric pressure ionisation techniques (electrospray and APcI) coupled to LC, nanoLC or infusion inlets.

Lines of expertise:

• Intact protein analysis. Top-down. Middle-down
• MS and IM-MS analysis of non-covalent complexes
• Peptide enzymatic digests analysis (MS, MS/MS) for protein identification and post-translational modifications (PTMs) determination. Bottom-up MS-based proteomics (in coordination with the PCB's Proteomic Platform)
• Small molecule analysis for exact mass determination

The facility provides consultancy services and analytical method development for specific applications, as well as mass spectra data processing. Samples are analysed either directly by the service or by researchers (previously trained by facility members), who can use mass spectrometers through an open-access system.

Equipment and specialised applications:

1-LTQ FT Ultra (Thermo Scientific). Hybrid Mass Spectrometer consisting of a linear Ion Trap, combined with a Fourier Transform Ion Cyclotron Cell. It is also provided with ECD and IRMPD for complementary protein fragmentation in the mass spectrometer. This instrument is used to perform Top-down MS protein analysis and Bottom-up applications. In its normal configuration, this instrument works coupled to an LC device (Surveyor LC (Thermo) and a chip-based nanoESI interface (Advion Triversa Nanomate).

2-Synapt High Definition MS System (Waters-Micromass). Hybrid QTOF instrument with an incorporated Triwave Cell. This instrument allows tandem MS to be combined with ion mobility, thus permitting the analysis of samples differentiated not only by their mass to charge ratio, but also by their shape and size. The instrument is used to analyse the macromolecular structure and conformation of intact proteins and to study non-covalent interactions. When working in its normal configuration, it is attached to a chip-based nanoESI interface (Advion Triversa Nanomate), thus combining the analysis of samples by infusion mode and by nanoLC coupling (NanoAcquity UPLC, Waters; purchased in 2009).

3-LCT-Premier XE (Waters-Micromass). Orthogonal acceleration time-of-fight mass spectrometer ideal for the analysis of high molecular weight compounds. This instrument has been modified to achieve inert conditions inside the ionisation source, in order to allow amide H/D exchange experiments for the study of the dynamic and structural properties of proteins and their complexes. In another set-up configuration, it is used to analyse small molecules for their structural characterisation and provides accuracies of less than 3ppm. For LC-purifications, it is normally attached to an LC device (UPLC Acquity, Waters).

Espectrometrí­a de Masas

Before sample submission:

Contact the MS team. We advise you on the best analytical methodology for your specific application.

Sample submission/reception:

There are two ways to submit samples for MS analysis:

1. Submission to the technician-run service by filling in the sample/s request form (available here or in the MSC lab).
2. Self-service (open-access) systems. Only for researchers qualified and trained to operate the mass spectrometers.
   If you plan to use the MS service often and would like to be considered for training, please contact Dr. Marta Vilaseca.

Custody and maintenance of samples:

When filling the request form, your sample or set of samples will be identified by a code number (apart from the users label). Depending on the analysis requested it will be classified in the corresponding "to-run" folder for each instrument.

The sample will be also classified and kept in the conditions specified in the request form.

If preferred you can keep your sample and bring it a day before the beginning of analysis (following scheduled dates).

Time of response for an analysis:

There is a calendar (contact the facility manager) for each instrument and submissions will be ordered by time of entry (IRB Barcelona groups are given preferential treatment).

Given the diversity of applications, some of which require only fast analysis while others require longer analysis time, the calendar will be organised as follows:

• Users can reserve a week in a specific instrument for long application (maximum 2 full weeks per user, depending on demand).
• Between long time applications we always reserve a week to perform shorter analysis in order to avoid delays.
• Mondays (or a pre-specified day) are reserved for the maintenance of the equipment and set up of the required technique pretended to use that week in each instrument.

Results delivery

Results performed by MS staff will be given in printed format (spectra and report specifying analytical conditions). Digital format data can also be kept if requested.

If further processing of your results is required a computer will be reserved in the facility for this purpose.

Our future goal is that users can also access data via a secured network. Data will be transferred to a common-server and back-ups will be performed automatically by the ITS Department. Data will be kept for a maximum of two years.

Espectrometrí­a de Masas

Manager
Marta Vilaseca
tel +34 93 403 98 15
e-mail: marta.vilasecairbbarcelona.org

Research Officers
Claudio Diema
tel +34 93 403 98 15
e-mail: claudio.diemairbbarcelona.org

Núria Omeñaca
tel +34 93 403 98 15
e-mail: nuria.omenacairbbarcelona.org

Espectrometrí­a de Masas

Does the solid-phase synthesis of a tetrapeptide represent a challenge at the onset of the XXI century? The case of cyclo[(3R)-3-hydroxydecanoyl-L-seryl-(3R)-3-hydroxydecanoyl-L-seryl]
Teixidó M, Caba JM, Prades R, Zurita E, Martinell M, Vilaseca M, Albericio F and Giralt E.
Int J Peptide Res Therapeutics, 13, 313-327 (2007)

Solid-state aggregates with unconventional (C-H)+...Cl- hydrogen bonding revealed by X-ray diffraction
Alcalde E, Mesquida N, Vilaseca M, Alvarez-Rúa C and García-Granda S.
Imidazolium-based dicationic cyclophanes. J Supramol Chem, 19 (7), 501-509 (2007)