Direct observation of solvent penetration during cold denaturation of E. coli phosphofructokinase-2

Ramirez-Sarmiento, C.A.; Baez, M; Wilson, C.A.M.; Babul, J.; Komives, E; Guixe, V


Phosphofructokinase-2 is a 66 kD homodimer whose subunits are associated by means of a bimolecular domain, the β-clasp, which is linked to the larger portion of each subunit by a reentrant chain topology. To investigate how this structural organization determines the folding pathway of Pfk-2, unfolding and folding kinetic experiments were performed. The folding pathway shows an unstructured monomeric intermediate and that most part of the dimer structure is reached as a slow concerted folding/association step with a quite folded transition state in terms of solvent exposure. Unfolding kinetics show a transient intermediate, probably a partially unfolded dimer. We propose that these characteristics arise by a mutual constrain between the large domain and the β-clasp domain imposed by their interrupted chain connectivity.

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Título de la Revista: Biophys
Volumen: 104
Número: 10
Fecha de publicación: 2013
Página de inicio: 2158
Página final: 2164
Notas: ISI