Surface Attachment Enhances the Thermodynamic Stability of Protein L

Gabriel Ortega, Martin Kurnik, Philippe Dauphin-Ducharme, Hui Li, Netzahualcoyotl Arroyo-Curras, Amanda Caceres, Kevin W. Plaxco

Research output: Contribution to journalArticle


Despite the importance of protein–surface interactions in both biology and biotechnology, our understanding of their origins is limited due to a paucity of experimental studies of the thermodynamics behind such interactions. In response, we have characterized the extent to which interaction with a chemically well-defined macroscopic surface alters the stability of protein L. To do so, we site-specifically attached a redox-reporter-modified protein variant to a hydroxy-terminated monolayer on a gold surface and then used electrochemistry to monitor its guanidine denaturation and determine its folding free energy. Comparison with the free energy seen in solution indicates that interaction with this surface stabilizes the protein by 6 kJ mol−1, a value that is in good agreement with theoretical estimates of the entropic consequences of surface-induced excluded volume effects, thus suggesting that chemically specific interactions with this surface (e.g., electrostatic interactions) are limited in magnitude.

Original languageEnglish (US)
Pages (from-to)1714-1718
Number of pages5
JournalAngewandte Chemie - International Edition
Issue number6
Publication statusPublished - Feb 4 2019



  • biophysics
  • electrochemistry
  • protein engineering
  • proteins
  • thermodynamics

ASJC Scopus subject areas

  • Catalysis
  • Chemistry(all)

Cite this

Ortega, G., Kurnik, M., Dauphin-Ducharme, P., Li, H., Arroyo-Curras, N., Caceres, A., & Plaxco, K. W. (2019). Surface Attachment Enhances the Thermodynamic Stability of Protein L. Angewandte Chemie - International Edition, 58(6), 1714-1718.