Probing the hydrophobic effect of noncovalent complexes by mass spectrometry

  • Claudia Bich
  • Samuel Baer
  • Matthias C. Jecklin
  • Renato ZenobiEmail author
Short Communication


The study of noncovalent interactions by mass spectrometry has become an active field of research in recent years. The role of the different noncovalent intermolecular forces is not yet fully understood since they tend to be modulated upon transfer into the gas phase. The hydrophobic effect, which plays a major role in protein folding, adhesion of lipid bilayers, etc., is absent in the gas phase. Here, noncovalent complexes with different types of interaction forces were investigated by mass spectrometry and compared with the complex present in solution. Creatine kinase (CK), glutathione S-transferase (GST), ribonuclease S (RNase S), and leucine zipper (LZ), which have dissociation constants in the nM range, were studied by native nanoelectrospray mass spectrometry (nanoESI-MS) and matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) combined with chemical cross-linking (XL). Complexes interacting with hydrogen bonds survived the transfer into gas phase intact and were observed by nanoESI-MS. Complexes that are bound largely by the hydrophobic effect in solution were not detected or only at very low intensity. Complexes with mixed polar and hydrophobic interactions were detected by nanoESI-MS, most likely due to the contribution from polar interactions. All noncovalent complexes could easily be studied by XL MALDI-MS, which demonstrates that the noncovalently bound complexes are conserved, and a real “snap-shot” of the situation in solution can be obtained.


MALDI Leucine Zipper Electron Capture Dissociation Noncovalent Interaction Polar Interaction 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.


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Copyright information

© American Society for Mass Spectrometry 2010

Authors and Affiliations

  • Claudia Bich
    • 1
  • Samuel Baer
    • 1
  • Matthias C. Jecklin
    • 1
  • Renato Zenobi
    • 1
    Email author
  1. 1.Department of Chemistry and Applied BiosciencesETH ZurichZurichSwitzerland

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