Conformational Characterization of Polyelectrolyte Oligomers and Their Noncovalent Complexes Using Ion Mobility-Mass Spectrometry

ATAKAY M., Aksakal F., BOZKAYA U., SALİH B., Wesdemiotis C.

JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY, vol.31, no.2, pp.441-449, 2020 (SCI-Expanded) identifier identifier identifier

  • Publication Type: Article / Article
  • Volume: 31 Issue: 2
  • Publication Date: 2020
  • Doi Number: 10.1021/jasms.9b00135
  • Journal Name: JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Academic Search Premier, Analytical Abstracts, Chimica, Compendex, EMBASE, MEDLINE
  • Page Numbers: pp.441-449
  • Keywords: polyelectrolyte, noncovalent complex, collision cross section, ion mobility separation, supramolecular compactness, PEPTIDE, PROTEINS, GAS, SEPARATION
  • Hacettepe University Affiliated: Yes

Abstract

Poly-L-lysine (PLL), polystyrenesulfonate (PSS), and a mixture of these polyelectrolytes were investigated by electrospray ionization ion mobility mass spectrometry. The IM step confirmed the formation of noncovalent (i.e., supramolecular) complexes between these polyelectrolytes, which were detected in various charge states and stoichiometries in the presence of their constituents. Experimental and theoretical collision cross sections (CCSs) were derived for both PLL and PSS oligomers as well as their noncovalent assemblies. PSS chains showed higher compactness with increasing size as compared to PLL chains, indicating that the intrinsic conformations of the polyelectrolytes depend on the nature of the functional groups on their side chains. The CCS data for the noncovalent complexes further revealed that assemblies with higher PLL content have higher CCS values than other compositions of similar mass and that PLL PSS complex formation is accompanied by significant size contraction.