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Hugh's work demonstrates of the potential of the high-resolution Electrospray Ionization/Ion Mobility Spectrometry (ESI/IMS) technique as an analytical separation tool in analyzing biomolecular mixtures to pursue astrobiological objectives of searching chemical signatures of life for in-situ exploration of solar system bodies in collaboration with Jet Propulsion Laboratory (JPL), Pasadena, CA. The identification of these molecules will help determine habitats that organisms can exist and whether indigenous organisms exist or have existed on the surface of Mars or in an undersea environment on Europa. A detailed organic chemical inventory of molecules present on these bodies will elucidate the origin of life on Earth and possibilities of life elsewhere in the Universe.
Current work studies the reactions of non-covalently bound metal complexes of biomolecules. Using electrospray ionization to generate molecular cpmplexes and clusters of metal cation, a general study of reactions that occur between cluster components, other than simple dissociations has been initiated. This method has been applied to investigate the atmospheric chemistry of a wide range of dicarboxylic acids. Further, biological applications have been demonstrated for the understanding interactions between metal and peptide allowing us to locate post-translational modified (PTM) residues in proteins/peptides. It is observed, for instance, that collision of a vibrationally excited sodium malonate cluster with a water molecule can trigger decomposition of malonic acid to carbon dioxide and acetic acid. Complexes of peptides possessing disulfide bonds with sodium and alkaline earth metal shows highly selective elimination of hydrogen disulfide (H2S2) via collisional activation. Further isolation of the products reveals the peptide sequence in the region between the newly formed dehydroalanine residues.
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Beauchamp Research Group |
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