Biological Mixtures (biological + mixture)

Distribution by Scientific Domains
Chemistry66%

Kinds of Biological Mixtures

  • complex biological mixture
    		•

    Selected Abstracts

    "Reverse degradomics", monitoring of proteolytic trimming by multi-CE and confocal detection of fluorescent substrates and reaction products

    ELECTROPHORESIS, Issue 13 2009
    Helene Piccard
    Abstract A platform for profiling of multiple proteolytic activities acting on one specific substrate, based on the use of a 96-channel capillary DNA sequencer with CE-LIF of labeled substrate peptides and reaction products is introduced. The approach consists of synthesis of a substrate peptide of interest, fluorescent labeling of the substrate, either aminoterminally by chemical coupling, or carboxyterminally by transglutaminase reaction, proteolysis by a biological mixture of proteases in the absence or presence of protease inhibitors, multi-channel analysis of substrate and reaction products, and data collection and processing. Intact substrate and reaction products, even when varying by only one amino acid, can be relatively semi-quantified in a high-throughput manner, yielding information on proteases acting in complex biological mixtures and without prepurification. Monitoring, classification and inhibition of multiple proteolytic activities are demonstrated on a model substrate, the aminoterminus of the mouse granulocyte chemotactic protein-2. In view of extensive processing of chemokines into various natural forms with different specific biological activities, and of the fragmentary knowledge of processing proteases, examples of processing by neutrophil degranulate, tumor cell culture fluids and plasma are provided. An example of selection and comparison of inhibitory mAbs illustrates that the platform is suitable for inhibitor screening. Whereas classical degradomics technologies analyze the substrate repertoire of one specific protease, here the complementary concept, namely the study of all proteases acting, in a biological context, on one specific substrate, is developed and tuned to identify key proteases and protease inhibitors for the processing of any biological substrate of interest. [source]

    Fragmentation patterns of new esterified and unesterified aromatic 1-hydroxymethylene-1, 1-bisphosphonic acids by ESI-MSn

    JOURNAL OF MASS SPECTROMETRY (INCORP BIOLOGICAL MASS SPECTROMETRY), Issue 8 2008
    Julie Hardouin
    Abstract 1-Hydroxymethylene-1,1-bisphosphonic acids (HMBPs) are compounds that have interesting pharmacological applications. Unfortunately few studies exist on their analyses by mass spectrometry (MS). In this work, we have analyzed new aromatic HMBPs and their prodrugs with electrospray tandem mass spectrometry (ESI-MSn). We describe, for the first time, a complete study of fragmentation patterns, in both positive and negative-ion modes. In positive mode, the cation dissociations are mainly elimination of water and phosphorus fragments. In negative mode, losses of ROH (RH, C6H5, CH3OC6H5) and HPO2 were observed. The results have revealed specific structural fingerprints for the screening of these compounds in complex biological mixtures. Copyright © 2008 John Wiley & Sons, Ltd. [source]

    Application of capillary electrophoresis mass spectrometry to the characterization of bacterial lipopolysaccharides

    MASS SPECTROMETRY REVIEWS, Issue 1 2007
    Jianjun Li
    Abstract Capillary electrophoresis (CE) is a high-resolution technique for the separation of complex biological mixtures and has been widely applied to biological analyses. The coupling of capillary electrophoresis with mass spectrometry (MS) provides a powerful approach for rapid identification of target analytes present at trace levels in biological matrices, and for structural characterization of complex biomolecules. Here we review the analytical potential of combined capillary electrophoresis electrospray mass spectrometry (CE-MS) for the analysis of bacterial lipopolysaccharides (LPS). This hyphened methodology facilitates the determination of closely related LPS glycoform and isoform families by exploiting differences in their unique molecular conformations and ionic charge distributions by electrophoretic separation. On-line CE-MS also provides an additional avenue to improve detection limits, which has been successfully applied to directly probe oligosaccharide LPS glycoform populations of bacteria isolated from infected animal models without the need for further passage. © 2006 Wiley Periodicals, Inc., Mass Spec Rev 26:35,50, 2007 [source]

    Study of bisphosphonates by matrix-assisted laser desorption/ionization mass spectrometry , influence of alkali atoms on fragmentation patterns

    RAPID COMMUNICATIONS IN MASS SPECTROMETRY, Issue 9 2009
    Erwann Guénin
    1-Hydroxymethylene-1,1-bisphosphonic acids (or bisphosphonates) are compounds that have interesting pharmacological applications. However, few mass spectrometric investigations have been carried out to determine their fragmentation patterns. Herein, we evaluated different matrices for the study by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOFMS) of the formation and fragmentation of the protonated, the cationized (MNa+ and MK+) and the deprotonated bisphosphonates. Some in-source fragmentations were observed both in positive and in negative ion modes. The fragmentation patterns obtained in post-source decay mode are also discussed. In contrast to previous electrospray ionization/multi-stage mass spectrometry (ESI-MSn) studies, some new fragmentation pathways were deduced and the effects of alkali ions on the fragmentation patterns were shown. The results summarized here completed the data previously recorded by ESI-MSn and could be used for the characterization of bisphosphonates as alkali complexes in biological mixtures. Copyright © 2009 John Wiley & Sons, Ltd. [source]

    Electrospray ionization tandem mass spectrometry fragmentation of protonated flavone and flavonol aglycones: a re-examination

    RAPID COMMUNICATIONS IN MASS SPECTROMETRY, Issue 2 2009
    Gonçalo C. Justino
    Flavonoids are important phytochemicals which have been intensively studied in the last decades in view of their antioxidant activity, which is of particular importance in the case of flavones and flavonols, that differ in a single 3-OH group. Mass spectrometry has been used to elucidate the structures of many types of flavonoids and their metabolites. The work we present here is focused on the electrospray ionization tandem mass spectrometry (ESI-MS/MS) analysis of flavone and flavonols aglycones. Their fragmentation mechanisms in the positive ion mode are described and compared with previously reported mechanisms. We analyzed flavonoid derivatives produced by reaction of the flavonoids with chemically synthesized hypohalous acids (HOCl, HOBr and HOI) and peroxynitrite, reactive species involved in the inflammatory response. All the proposed pathways have been analyzed using computational chemistry methods in order to seek for possible variations and establish the most plausible ones. We observed that the losses of one and two CO molecules can be useful in terms of antioxidant activity prediction. Losses of one and two C2H2O groups are also informative in terms of structure and activity predictions. The retro-Diels-Alder fragmentations, and subsequent neutral losses, were reviewed and, according to our calculations, the most plausible structures for the product ions were established. These fingerprints will be of great value for differentiating flavonoids from other compounds in complex biological mixtures and for a thorough structural identification of flavonoid aglycones and their invivo metabolites. Copyright © 2008 John Wiley & Sons, Ltd. [source]