The introduction of two new ionization methods in mass spectrometry,
electrospray and matrix-assisted laser desorption ionization (Maldi), in
the late 80's have revolutionized protein chemistry. They both allow the
accurate molecular weight determination of proteins and peptides, and
from other biomolecules like nucleotides, sugars, etc... The inventors
were granted the nobel prize in chemistry in 2003.
We were happy to introduce these techniques, together with plasma desorption in
the Benelux. Our mass spectrometry unit is at present equiped with five mass spectrometers.
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| Electrospray Ionisation Mass Spectrometers |
A peptide/protein solution is sprayed from a capillary by applying
a high voltage. Due to electrostatic interactions in the droplets, multiple
charged ions are formed. This method allows proteins up to 100 kDa to be
determined with 0.01% accuracy. We use two different systems:
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A Q-TOF I (Micromass, installed May 1998). This instrument has a tremendously
increased sensitivity, particularly for MS/MS applications.This instrument is recently
equiped with an automated nano ESI-Source (Advion). This allows us to automatically inject samples from
multi-well plates. This has been applied for the study of non-covalent protein-ligand interactions.
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| Nano-LC-MS configuration on the Q-TOF and the nano-electrospray source. |
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A novel Q-TRAP linear ion trap instrument (Applied Biosystems, installed October 1998).
This instrument is a remarkable hybrid between a triple quadrupole and an ion
trap instrument. The triple quad allows the typical scan functions (parent ion
scans, MRM,) that are unique for this configuration, while Q3 is functioning
as a linear ion trap with larger ion storage capacity, with MS3 functionality).
It has an on-line micro-capillary LC-system (Ultimate, LC-Packings)
with a Famos autosampler fitted to it.
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| Q-TRAP |
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| Matrix-assisted Laser Desorption Mass Spectrometer |
Maldi uses laserlight to desorb proteins and peptides from a matrix
(existing of aromatic acid compounds). It allows proteins up to 500 kDa
to be analyzed with 0.1% accuracy.
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We recently introduced the novel 4700 Proteomics analyzer (Applied Biosystems,
installed October 2002). This is a novel MALDI TOF/TOF instrument capable of
high throughput protein identification in proteomics approaches, based
on both peptide fingerprinting and MS/MS. It provides unique high energy
fragmentation MS/MS spectra that allows differentiating Ile and Leu, two
amino acids that have equal masses.
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| The 4700 proteomics analyzer. |
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| SELDI-TOF |
We also obtained a SELDI protein chip analyzer (Ciphergen, installed 2002).
SELDI technology enables selective protein retention on ProteinChip Array
surfaces by means of distinct chromatographic or bioaffinity surfaces.
ProteinChip Arrays are available with a variety of chromatographic surfaces
including reversed phase, cationic, anionic and metal affinity.
The method is widely used in biomarker analysis and bioprocessing.
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| Proteomics |
Our laboratory is working on proteomic analysis by both gel and non-gel based
multidimensional separation technology. For gelelectrophoresis, we are equiped with a Bio-Rad
platform based on a dodecacell and PDQuest imaging and analysis software. For non-gel applications
we are using ICAT, ITRAQ and other stable isotopic labeling techniques combined with 2D-LC based on the
LC Packings dual gradient 2D-LC system.
For more information about the research fields , click here.
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These facilities are available for both academic and industrial interested.
For further information regarding mass spectrometric applications please
contact Prof. Dr. Bart Devreese.
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