ITC-derived binding affinity may be biased due to titrant (nano)-aggregation. Binding of halogenated benzotriazoles to the catalytic domain of human protein kinase CK2

The binding of four bromobenzotriazoles to the catalytic subunit of human protein kinase CK2 was assessed by two complementary methods: Microscale Thermophoresis (MST) and Isothermal Titration Calorimetry (ITC). New algorithm proposed for the global analysis of MST pseudo-titration data enabled reliable determination of binding affinities for two distinct sites, a relatively strong one with the Kd of the order of 100 nM and a substantially weaker one (Kd > 1 μM). The affinities for the strong binding site determined for the same protein-ligand systems using ITC were in most cases approximately 10-fold underestimated. The discrepancy was assigned directly to the kinetics of ligand nano-aggregates decay occurring upon injection of the concentrated ligand solution to the protein sample. The binding affinities determined in the reverse ITC experiment, in which ligands were titrated with a concentrated protein solution, agreed with the MST-derived data. Our analysis suggests that some ITC-derived Kd values, routinely reported together with PDB structures of protein-ligand complexes, may be biased due to the uncontrolled ligand (nano)-aggregation, which may occur even substantially below the solubility limit.

Medienart:

E-Artikel

Erscheinungsjahr:

2017

Erschienen:

2017

Enthalten in:

Zur Gesamtaufnahme - volume:12

Enthalten in:

PloS one - 12(2017), 3 vom: 16., Seite e0173260

Sprache:

Englisch

Beteiligte Personen:

Winiewska, Maria [VerfasserIn]
Bugajska, Ewa [VerfasserIn]
Poznański, Jarosław [VerfasserIn]

Links:

Volltext

Themen:

86110UXM5Y
Benzotriazole
CSNK2A1 protein, human
Casein Kinase II
EC 2.7.11.1
Journal Article
Ligands
Protein Kinase Inhibitors
Triazoles

Anmerkungen:

Date Completed 25.08.2017

Date Revised 14.01.2020

published: Electronic-eCollection

Citation Status MEDLINE

doi:

10.1371/journal.pone.0173260

funding:

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

NLM269643257