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Updated: May 22, 2026

Paramagnetic Relaxation Enhancement for Detecting and Characterizing Self-Associations of Intrinsically Disordered Proteins
Published on: September 23, 2021
Paramagnetic relaxation enhancement for the characterization of the conformational heterogeneity in two-domain
Ivano Bertini1, Claudio Luchinat, Malini Nagulapalli
1Magnetic Resonance Center (CERM), University of Florence, Via L. Sacconi 6, 50019 Sesto Fiorentino (FI), Italy. ivanobertini@cerm.unifi.it
Abstract:
Multidomain proteins are often composed of rigid domains that can reorient in solution more or less freely. Calmodulin (CaM) is a two domain protein which can experience a large degree of conformational freedom thanks to a mobile linker connecting the N-terminal and C-terminal domains of the protein. The maximum occurrences (MOs) of the possible protein conformations have been analyzed using the paramagnetic relaxation enhancements (PREs) induced by a gadolinium(III) ion together with the paramagnetic pseudocontact shift and residual dipolar coupling restraints measured in the presence of terbium(III), thulium(III) or dysprosium(III) ions. The results suggest that the PREs provide complementary information useful for improving the description of the conformational heterogeneity of the protein. The data, acquired at 298 K and at 278 K, suggest that compact conformations are disfavoured by decreasing the temperature.
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