Investigation of pH-induced protein conformation changes by nanomechanical deflection

Langmuir. 2014 Mar 4;30(8):2109-16. doi: 10.1021/la403981t. Epub 2014 Feb 19.

Abstract

Broad-spectrum biosensing technologies examine sensor signals using biomarkers, such as proteins, DNA, antibodies, specific cells, and macromolecules, based on direct- or indirect-conformational changes. Here, we have investigated the pH-dependent conformational isomerization of human serum albumin (HSA) using microcantilevers as a sensing platform. Native and denatured proteins were immobilized on cantilever surfaces to understand the effect of pH on conformational changes of the protein with respect to the coupling ligand. Our results show that protonation and deprotonation of amino acid residues on proteins play a significant role in generating charge-induced cantilever deflection. Surface plasmon resonance (SPR) was employed as a complementary technique to validate the results.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Biosensing Techniques / methods*
  • Humans
  • Hydrogen-Ion Concentration
  • Protein Conformation
  • Serum Albumin / chemistry*

Substances

  • Serum Albumin