Rapid capillary electrophoresis time-of-flight mass spectrometry separations of peptides and proteins using a monoquaternarized piperazine compound (M7C4I) for capillary coatings

Authors

  • Anisa Elhamili,

    1. Department of Physical and Analytical Chemistry, Analytical Chemistry, Biomedical Center, Uppsala University, Uppsala, Sweden
    Search for more papers by this author
  • Magnus Wetterhall,

    1. Department of Physical and Analytical Chemistry, Analytical Chemistry, Biomedical Center, Uppsala University, Uppsala, Sweden
    Search for more papers by this author
  • Björn Arvidsson,

    1. Department of Physical and Analytical Chemistry, Analytical Chemistry, Biomedical Center, Uppsala University, Uppsala, Sweden
    Search for more papers by this author
  • Roberto Sebastiano,

    1. Department of Chemistry, Materials and Chemical Engineering “Giulio Natta”, Polytechnic of Milano, Milano, Italy
    Search for more papers by this author
  • Pier Giorgio Righetti,

    1. Department of Chemistry, Materials and Chemical Engineering “Giulio Natta”, Polytechnic of Milano, Milano, Italy
    Search for more papers by this author
  • Jonas Bergquist Professor

    Corresponding author
    1. Department of Physical and Analytical Chemistry, Analytical Chemistry, Biomedical Center, Uppsala University, Uppsala, Sweden
    • Department of Physical and Analytical Chemistry, Analytical Chemistry, Uppsala University, P.O. Box 599, SE-751 24 Uppsala, Sweden Fax: +46-18-471-3692
    Search for more papers by this author

Abstract

A monoquaternarized piperazine, 1-(4-iodobutyl) 4-aza-1-azoniabicyclo[2,2,2] octane iodide (M7C4I), has been evaluated as a surface derivatization reagent for CE in combination with TOF MS for the analysis of proteins, peptides, and protein digests. The M7C4I piperazine, at alkaline pH, forms a covalent bond via alkylation of the ionized silanols producing a cationic surface with a highly stable and reversed EOF. The obtained surface yields rapid separations (less than 5 min) of peptides and proteins at acidic pH with high separation efficiencies (up to 1.1×106 plates/m for peptides and up to 1.8×106 plates/m for proteins) and no observed bleeding of the coating reagent into the mass spectrometer. The simplicity of the coating procedure also enables fast (2 min) regeneration of the surface, if necessary. This is useful in the analysis of complex samples in order to prevent possible memory effects. The potential of using M7C4I-coated capillaries for MS analysis of complex samples is demonstrated by the separation of peptides, proteins, and protein digests. Even more, the spectacular thing in which large intact proteins with molecular masses over 0.5 MDa could be separated. The coating showed good ability to handle these large proteins with high efficiency and retained peak shape as demonstrated by separation of IgG1 (150 kDa) and thyroglobulin (669 kDa).

Ancillary