6-Amidopyrene as a label-assisted laser desorption/ionization (LA-LDI) enhancing tag: development of photoaffinity pyrene derivative

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Abstract

Pyrene-conjugated compounds are detected by label-assisted laser desorption/ionization mass spectrometry (LA-LDI MS) without matrixes. We found that 6-amidopyrene derivatives were highly detectable by the LDI MS instrument equipped with a 355 nm laser. In a certain case of a 6-amidopyrene derivative, a molecular ion peak [M]+• and a characteristic fragment ion peak [M–42]+• were detected in an amount of only 10 fmol. The latter peak, corresponding to the 6-aminopyrene fragment, might be generated in situ by the removal of ketene (CH2=C=O) from the parent molecule. A photoaffinity amidopyrene derivative of an antitumor macrolide aplyronine A (ApA–PaP) was synthesized, which showed potent cytotoxicity and actin-depolymerizing activity. In an LDI MS analysis of the MeOH- and water-adducts of ApA–PaP, oxime N–O bonds as well as amidopyrene N-acetyl moieties were preferentially cleaved, and their internal structures were confirmed by MS/MS analysis. Amidopyrene moiety might enhance fragmentation and stabilize the cleaved fragments by intramolecular or intermolecular weak interactions including hydrogen bonding. Our chemical probe methods might contribute to a detailed analysis of binding modes between various ligands and target biomacromolecules that include multiple and weak interactions.

Journal

  • Scientific reports

    Scientific reports (5), 17853, 2015-12

    Nature Publishing Group

Keywords

Codes

  • NII Article ID (NAID)
    120005691345
  • Text Lang
    ENG
  • Article Type
    journal article
  • ISSN
    2045-2322
  • Data Source
    IR 
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