A calorimetric and structural analysis of cooperativity in the thermal unfolding of the PDZ tandem of human Syntenin-1.

Autor: Martinez JC; Department of Physical Chemistry, Institute of Biotechnology and Excellence Unit in Chemistry Applied to Biomedicine and Environment, Faculty of Sciences, University of Granada, Avda. Fuentenueva, s/n, 18071 Granada, Spain. Electronic address: jcmh@ugr.es., Ruiz-Sanz J; Department of Physical Chemistry, Institute of Biotechnology and Excellence Unit in Chemistry Applied to Biomedicine and Environment, Faculty of Sciences, University of Granada, Avda. Fuentenueva, s/n, 18071 Granada, Spain. Electronic address: jruizs@ugr.es., Resina MJ; Department of Physical Chemistry, Institute of Biotechnology and Excellence Unit in Chemistry Applied to Biomedicine and Environment, Faculty of Sciences, University of Granada, Avda. Fuentenueva, s/n, 18071 Granada, Spain. Electronic address: mjresina@ugr.es., Montero F; Department of Physical Chemistry, Institute of Biotechnology and Excellence Unit in Chemistry Applied to Biomedicine and Environment, Faculty of Sciences, University of Granada, Avda. Fuentenueva, s/n, 18071 Granada, Spain. Electronic address: fmontero@ugr.es., Camara-Artigas A; Department of Chemistry and Physics, Agrifood Campus of International Excellence (ceiA3) and CIAMBITAL, University of Almería, Carretera de Sacramento s/n, 04120 Almería, Spain. Electronic address: acamara@ual.es., Luque I; Department of Physical Chemistry, Institute of Biotechnology and Excellence Unit in Chemistry Applied to Biomedicine and Environment, Faculty of Sciences, University of Granada, Avda. Fuentenueva, s/n, 18071 Granada, Spain. Electronic address: iluque@ugr.es.
Jazyk: angličtina
Zdroj: International journal of biological macromolecules [Int J Biol Macromol] 2023 Jul 01; Vol. 242 (Pt 1), pp. 124662. Date of Electronic Publication: 2023 Apr 27.
DOI: 10.1016/j.ijbiomac.2023.124662
Abstrakt: Syntenin-1 is a multidomain protein containing a central tandem of two PDZ domains flanked by two unnamed domains. Previous structural and biophysical studies show that the two PDZ domains are functional both isolated and in tandem, occurring a gain in their respective binding affinities when joined through its natural short linker. To get insight into the molecular and energetic reasons of such a gain, here, the first thermodynamic characterization of the conformational equilibrium of Syntenin-1 is presented, with special focus on its PDZ domains. These studies include the thermal unfolding of the whole protein, the PDZ-tandem construct and the two isolated PDZ domains using circular dichroism, differential scanning fluorimetry and differential scanning calorimetry. The isolated PDZ domains show low stability (ΔG < 10 kJ·mol -1 ) and poor cooperativity compared to the PDZ-tandem, which shows higher stability (20-30 kJ·mol -1 ) and a fully cooperative behaviour, with energetics similar to that previously described for archetypical PDZ domains. The high-resolution structures suggest that this remarkable increase in cooperativity is associated to strong, water-mediated, interactions at the interface between the PDZ domains, associated to nine conserved hydration regions. The low T m value (45 °C), the anomalously high unfolding enthalpy (>400 kJ·mol -1 ), and native heat capacity values (above 40 kJ·K -1 ·mol -1 ), indicate that these interfacial buried waters play a relevant role in Syntenin-1 folding energetics.
Competing Interests: Declaration of competing interest The authors declare that they do not have conflicts of interest.
(Copyright © 2023 The Authors. Published by Elsevier B.V. All rights reserved.)
Databáze: MEDLINE
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