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Spectrometric Fragmentation (spectrometric + fragmentation)

Distribution by Scientific Domains
Chemistry100%

Kinds of Spectrometric Fragmentation

  • mass spectrometric fragmentation
    		•

    Selected Abstracts

    Mass spectrometric and chemical stability of the Asp-Pro bond in herpes simplex virus epitope peptides compared with X-Pro bonds of related sequences

    JOURNAL OF PEPTIDE SCIENCE, Issue 8 2002
    Zsolt Skribanek
    Abstract The mass spectrometric analysis of the immunodominant epitope region (273,284) of herpes simplex virus type 1 (HSV-1) glycoprotein D (gD) showed a favoured fission at the Asp-Pro peptide bond. The fast atom bombardment collision induced dissociation (FAB-CID) study of closely related X-Pro peptides documented that neither the length nor the amino acid composition of the peptide has a significant influence on this preferential cleavage. At the same time the DP bond proved to be sensitive to acidic conditions in the course of peptide synthesis. These observations prompted us to compare the chemical and mass spectrometric stability of a new set of nonapeptides related to the 273,284 epitope region of gD, i.e. SALLEDPVG and SALLEXPVG peptides, where X = A, K, I, S, F, E or D, respectively. The chemical stability of these peptides during acidic hydrolysis was investigated by electrospray ionization mass spectrometry (ESI-MS) and the products were identified by ESI-MS and on-line high performance liquid chromatography,mass spectrometry (HPLC-MS). The mass spectrometric fragmentation and bond stability of the untreated peptide samples were also studied using ESI-MS and liquid secondary ion mass spectrometry (LSIMS). Both the chemical hydrolysis and the mass spectrometric fragmentation showed that the Asp-Pro bond could easily be cleaved, while the KP bond proved to be stable under both circumstances. On the other hand, the XP bond (X = A, I, S, F or E) fragmented easily under the mass spectrometric conditions, but was not sensitive to the acidolysis. Copyright © 2002 European Peptide Society and John Wiley & Sons, Ltd. [source]

    High-performance liquid chromatography/mass spectrometric and proton nuclear magnetic resonance spectroscopic studies of the transacylation and hydrolysis of the acyl glucuronides of a series of phenylacetic acids in buffer and human plasma

    RAPID COMMUNICATIONS IN MASS SPECTROMETRY, Issue 20 2010
    Elin S. Karlsson
    The use of high-performance liquid chromatography/mass spectrometry (HPLC/MS) and proton nuclear magnetic resonance (1H NMR) spectroscopy for the kinetic analysis of acyl glucuronide (AG) isomerisation and hydrolysis of the 1-,- O -acyl glucuronides (1-,- O -AG) of phenylacetic acid, (R)- and (S)-,-methylphenylacetic acid and ,,,-dimethylphenylacetic acid is described and compared. Each AG was incubated in both aqueous buffer, at pH 7.4, and control human plasma at 37°C. Aliquots of these incubations, taken throughout the reaction time-course, were analysed by HPLC/MS and 1H NMR spectroscopy. In buffer, transacylation reactions predominated, with relatively little hydrolysis to the free aglycone observed. In human plasma incubations the calculated rates of reaction were much faster than for buffer and, in contrast to the observations in buffer, hydrolysis to the free aglycone was a significant contributor to the overall reaction. A diagnostic analytical methodology based on differential mass spectrometric fragmentation of 1-, -O- AGs compared to the 2-, 3- and 4-positional isomers, which enables selective determination of the former, was confirmed and applied. These findings show that HPLC/MS offers a viable alternative to the more commonly used NMR spectroscopic approach for the determination of the transacylation and hydrolysis reactions of these AGs, with the major advantage of having the capability to do so in a complex biological matrix such as plasma. Copyright © 2010 John Wiley & Sons, Ltd. [source]

    Identification of diastereomeric chlorophyll allomers by atmospheric pressure chemical ionisation liquid chromatography/tandem mass spectrometry

    RAPID COMMUNICATIONS IN MASS SPECTROMETRY, Issue 11 2003
    J. Stuart Walker
    Atmospheric pressure chemical ionisation liquid chromatography/mass spectrometry (APCI-LC/MS) has been used for identification of the epimers of hydroxy, methoxy and methoxylactone allomers of chlorophyll a (132 -HO-chl a, 132 -MeO-chl a and 151 -MeO-lact-chl a), the hydroxy allomer of bacteriochlorophyll a (132 -HO-bchl a) and the hydroxy and methoxylactone allomers of bacterioviridin a (132 -HO-bvir a and 151 -MeO-lact-bvir a). The APCI mass spectra show that facile fragmentations involve the methoxyl or hydroxyl groups at the C-132 or C-151 chiral centres. Losses involving the C-132 or C-151 hydroxyl or methoxyl groups occur more easily from the S -epimer than from the R -epimer due to the greater relief of the steric strain associated with interaction with the bulky C-17 substituent. The differences in mass spectrometric fragmentation can be used as a diagnostic tool for the assignment of the stereochemical configuration at the C-132 or C-151 chiral centres. Copyright © 2003 John Wiley & Sons, Ltd. [source]

    A Targeted Releasable Affinity Probe (TRAP) for In Vivo Photocrosslinking

    CHEMBIOCHEM, Issue 9 2009
    Ping Yan Dr.
    Abstract A protein TRAP: The in vivo photocrosslinking of TRAP after its intracellular targeting to a binding sequence on the bait protein stabilizes protein interactions. Because the crosslinker is releasable, simple mass spectrometry can be used to identify the protein binding sites after purification. Protein crosslinking, especially coupled to mass-spectrometric identification, is increasingly used to determine protein binding partners and protein,protein interfaces for isolated protein complexes. The modification of crosslinkers to permit their targeted use in living cells is of considerable importance for studying protein-interaction networks, which are commonly modulated through weak interactions that are formed transiently to permit rapid cellular response to environmental changes. We have therefore synthesized a targeted and releasable affinity probe (TRAP) consisting of a biarsenical fluorescein linked to benzophenone that binds to a tetracysteine sequence in a protein engineered for specific labeling. Here, the utility of TRAP for capturing protein binding partners upon photoactivation of the benzophenone moiety has been demonstrated in living bacteria and mammalian cells. In addition, ligand exchange of the arsenic,sulfur bonds between TRAP and the tetracysteine sequence to added dithiols results in fluorophore transfer to the crosslinked binding partner. In isolated protein complexes, this release from the original binding site permits the identification of the proximal binding interface through mass spectrometric fragmentation and computational sequence identification. [source]