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Updated: May 5, 2026

Investigating Protein Sequence-structure-dynamics Relationships with Bio3D-web
Published on: July 16, 2017
A thermodynamic study of the third PDZ domain of MAGUK neuronal protein PSD-95 reveals a complex three-state folding
Javier Murciano-Calles1, Jose C Martinez1, Marta Marin-Argany2
1Departamento de Química Física e Instituto de Biotecnología, Facultad de Ciencias, Universidad de Granada, 18071 Granada, Spain.
Abstract:
The relevance of the C-terminal α helix of the PDZ3 domain of PSD95 in its unfolding process has been explored by achieving the thermodynamic characterization of a construct where the sequence of the nine residues corresponding to such motif has been deleted. Calorimetric traces at neutral pH require the application of a three-state model displaying three different equilibrium processes in which the intermediate state self-associates upon heating, being stable and populated in a wide temperature range. Temperature scans followed by circular dichroism, Fourier transform infrared spectroscopy and dynamic light scattering support the presence of such oligomeric-partially folded species. This study reveals that the deletion of the α3-helix sequence results in a more complex description of the domain unfolding.
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