scholarly journals Using molecular recognition of β-cyclodextrin to determine molecular weights of low-molecular-weight explosives by MALDI-TOF mass spectrometry

2006 ◽  
Vol 17 (2) ◽  
pp. 189-193 ◽  
Author(s):  
Min Zhang ◽  
Zhen Shi ◽  
Yinjuan Bai ◽  
Yong Gao ◽  
Rongzu Hu ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Molecular Weight ◽  
Molecular Recognition ◽  
Low Molecular Weight ◽  
Maldi Tof Mass Spectrometry ◽  
Molecular Weights ◽  
Maldi Tof

Mapping Low Molecular Weight Plasma Proteome of Chronic Lymphoblastic Leukemia Patients Using MALDI-TOF Mass Spectrometry.

Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 1910-1910 ◽  
Author(s):  
Jianbiao Zhou ◽  
Zhinan Xia ◽  
Aihong Li ◽  
John G. Gribben
Keyword(s):  
Mass Spectrometry ◽  
Molecular Weight ◽  
Lymphoblastic Leukemia ◽  
Prognostic Significance ◽  
Peptide Sequence ◽  
Low Molecular Weight ◽  
Plasma Proteome ◽  
Maldi Tof ◽  
Apolipoprotein A ◽  
Healthy Donors

Abstract In the post-genomic era, even with advances in analytical separation methods, analysis of human serum or plasma remains complex. However differential serum protein and peptide profiles have already been identified in cancer, infectious disease, cardiovascular disease, AIDS and diabetes. Profiling all peptides in plasma is hindered by the abundant albumin, macroglobulin, which may account for more than 80% of total protein. It is estimated that there is at least 7–8 orders of magnitude difference between most abundant plasma peptides and lower abundant ones, although biomarkers are often among the low abundance proteins. Contamination of electrolytes and lipids further complicate analysis of plasma proteome by mass spectrometer because these contaminants inhibit the ionization of native peptide. Here we used a pre-fractionation and ultrafilitration column (molecular weight cutoff 30 KD) strategy to treat plasma samples, and then used matrix assisted laser desorption/ionization time of-flight (MALDI-TOF) to map low molecular weight peptides of CLL patients and healthy donors. Plasma was collected from 34 untreated patients with B-cell chronic lymphocytic leukemia (CLL) and 19 healthy donors. 25mM NH4HCO3, pH 8.2, 20% (v/v) acetonitrile was added to 5 mL of plasma, after vortexing to denature proteins. The mixture was applied onto an Amicon ultra-15 centrifugal filter unit (MWCO 30 KD), and centrifuged. The flow-through was then transferred to a centrifugal concentrator (MWCO 3 KD) until 90% of the volume had gone through the membrane and the volume further reduced. An aliquot was desalted, purified and then spotted on 96-well gold MALDI plates with sinapic acid matrix. Measurements were performed in linear mode with an Applied Biosystems Voyager System with acquisition mass range 3–10 KD. The next-well external calibration was used to calibrate each sample plate and sample preparation. SDS-PAGE analysis demonstrated significant depletion of large, abundant proteins, and enrichment of low molecular peptides in ultrafiltrate. Among the peptides identified in all 34 CLL patients that was absent in 19 healthy donor plasma was a m/z 4340.7 Da peptide. Sequence analysis of this peptide was performed by microcapillary reverse-phase HPLC nano-electrospray tandem mass spectrometry (μLC/MS/MS) and revealed that this peptide sequence is DEPPQSPWDRVKDLATVYVDVLKDSGRDYVSQFEGSALG derived from apolipoprotein A-I (amino acid 25–63 ). We performed ELISA to quantify apolipoprotein A-I in plasma. The mean value plasma apolipoprotein A-I of the 34 CLL patients was 20 mg/dL (range 6.6 to 51.7) compared to 10.4 mg/dL (range 2.2 to 16.9) in the 19 healthy donors (p-value < 0.002). Higher levels of apolipoprotein A-I did not appear to be associated with prognostic significance in the CLL patients in terms of predicting time from diagnosis to requirement for treatment. However, this study demonstrates the feasibility of mapping low molecular weight of plasma proteome by MALDI-TOF to discover novel biomarkers of disease. The identification and characterization of such disease-specific peptides and proteins in CLL patient plasma will help in diagnosis and understanding of CLL biology.

scholarly journals Endogenous Plasma Peptide Detection and Identification in the Rat by a Combination of Fractionation Methods and Mass Spectrometry

2007 ◽  
Vol 2 ◽  
pp. 117727190700200
Author(s):  
Fabrice Bertile ◽  
Flavie Robert ◽  
Véronique Delval-Dubois ◽  
Sarah Sanglier ◽  
Christine Schaeffer ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Molecular Weight ◽  
Membrane Filtration ◽  
Solid Phase ◽  
Weight Fraction ◽  
Peptide Sequence ◽  
Low Molecular Weight ◽  
Maldi Tof Ms ◽  
Maldi Tof ◽  
Tof Ms

Mass spectrometry-based analyses are essential tools in the field of biomarker research. However, detection and characterization of plasma low abundance and/or low molecular weight peptides is challenged by the presence of highly abundant proteins, salts and lipids. Numerous strategies have already been tested to reduce the complexity of plasma samples. The aim of this study was to enrich the low molecular weight fraction of rat plasma. To this end, we developed and compared simple protocols based on membrane filtration, solid phase extraction, and a combination of both. As assessed by UV absorbance, an albumin depletion >99% was obtained. The multistep fractionation strategy (including reverse phase HPLC) allowed detection, in a reproducible manner (CV < 30%-35%), of more than 450 peaks below 3000 Da by MALDI-TOF/MS. A MALDI-TOF/MS-determined LOD as low as 1 fmol/μL was obtained, thus allowing nanoLC-Chip/MS/MS identification of spiked peptides representing ~10–6% of total proteins, by weight. Signal peptide recovery ranged between 5%-100% according to the spiked peptide considered. Tens of peptide sequence tags from endogenous plasma peptides were also obtained and high confidence identifications of low abundance fibrinopeptide A and B are reported here to show the efficiency of the protocol. It is concluded that the fractionation protocol presented would be of particular interest for future differential (high throughput) analyses of the plasma low molecular weight fraction.

Capture and Analysis of Low Molecular Weight Ligands by Surface Plasmon Resonance Combined with Mass Spectrometry

2001 ◽  
Vol 7 (4-5) ◽  
pp. 385-391 ◽  
Author(s):  
Carsten P. Sönksen ◽  
Peter Roepstorff ◽  
Per-Olof Markgren ◽  
U. Helena Danielson ◽  
Markku D. Hämäläinen ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Molecular Weight ◽  
Surface Plasmon Resonance ◽  
Electrospray Ionization ◽  
Surface Plasmon ◽  
Plasmon Resonance ◽  
Ion Trap ◽  
Low Molecular Weight ◽  
Maldi Tof ◽  
Hiv 1

The combination of biomolecular interaction analysis (BIA)by surface plasmon resonance (SPR)and nano-electrospray ionization ion trap mass spectrometry (nanoESI-Ion Trap MS)as well as matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-ToF MS)is demonstrated for the binding of low molecular weight inhibitors (∼ 600 Da) to HIV-1 protease. Inhibitors were captured on sensor chips of a manual or an automated SPR biosensor, to which HIV-1 protease was immobilized. Compounds and buffer components that bound unspecifically to the sensor surface were removed and the inhibitors were eluted in a minimal volume (3 μL), between air bubbles, in order to prevent dispersion of analyte into buffer eluent. Molecular weights were subsequently determined by mass spectrometry, structural information was obtained by MALDI-ToF post-source decay as well as by electrospray ionization tandem mass spectrometry (MS/MS)analysis. Furthermore, competition experiments, using a mixture of different ligands, demonstrated that the peak intensities in the MALDI-ToF spectrum could be used for relative quantification of the amount of the different ligands bound to the immobilized target. Methodology for automated capture and elution of analytes was developed and evaluated.

Sign in / Sign up

Export Citation Format

Share Document