Development and Application of a High Throughput Protein Unfolding Kinetic Assay

PLoS One. 2016 Jan 8;11(1):e0146232. doi: 10.1371/journal.pone.0146232. eCollection 2016.

Abstract

The kinetics of folding and unfolding underlie protein stability and quantification of these rates provides important insights into the folding process. Here, we present a simple high throughput protein unfolding kinetic assay using a plate reader that is applicable to the studies of the majority of 2-state folding proteins. We validate the assay by measuring kinetic unfolding data for the SH3 (Src Homology 3) domain from Actin Binding Protein 1 (AbpSH3) and its stabilized mutants. The results of our approach are in excellent agreement with published values. We further combine our kinetic assay with a plate reader equilibrium assay, to obtain indirect estimates of folding rates and use these approaches to characterize an AbpSH3-peptide hybrid. Our high throughput protein unfolding kinetic assays allow accurate screening of libraries of mutants by providing both kinetic and equilibrium measurements and provide a means for in-depth ϕ-value analyses.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Chromatography, Gel
  • Guanidine / chemistry
  • High-Throughput Screening Assays
  • Kinetics
  • Microfilament Proteins / chemistry*
  • Microfilament Proteins / isolation & purification
  • Models, Molecular
  • Protein Denaturation
  • Protein Stability
  • Proteolysis
  • Scattering, Small Angle
  • Solutions
  • Thermodynamics
  • X-Ray Diffraction
  • src Homology Domains

Substances

  • Microfilament Proteins
  • Solutions
  • Guanidine