Related Experiment Video
Updated: Dec 14, 2025

Determination of the Gas-phase Acidities of Oligopeptides
Published on: June 24, 2013
Determination of pKa Values in Intrinsically Disordered Proteins
Brandon Payliss1, Anthony Mittermaier2
1Department of Biochemistry, University of Toronto, Toronto, ON, Canada. brandon.payliss@mail.utoronto.ca.
Abstract:
Electrostatic interactions in intrinsically disordered proteins (IDPs) and regions (IDRs) can strongly influence their conformational sampling. Side chain pKa values provide information on the electrostatic interaction energies of individual side chains and are required to accurately determine the molecular net charge and charge distribution. Nuclear magnetic resonance (NMR) spectroscopy is the premier method for measuring side chain pKa values as it can detect the ionization states of individual side chains in an IDP or IDR simultaneously. In this section, we outline the use of NMR spectroscopy to determine side chain-specific pKas for each of the nine aspartates, five glutamates, and one histidine contained in a highly acidic 35-residue intrinsically disordered peptide.
More Related Videos
Related Concept Videos
Intrinsically Disordered Proteins
Intrinsically Disordered Proteins
Acid and Bases: Ka, pKa, and Relative Strengths
Factors Affecting Dissolution: Drug pKa, Lipophilicity and GI pH
A drug's pKa and the pH of the gastrointestinal (GI) tract play crucial roles...
Basicity of Aliphatic Amines
To measure the basicity of amines, two conventions are generally used. The first defines Kb as the basicity constant for the deprotonation reaction of water by the amine, as presented in Figure 1. Conventionally, lower Kb indicates higher...
The Equilibrium Binding Constant and Binding Strength

