ClpXP complex is an ATP-dependent mitochondrial matrix
protease
that binds, unfolds, translocates, and subsequently degrades specific
protein substrates. Its mechanisms of operation are still being debated,
and several have been proposed, including the sequential translocation
of two residues (SC/2R), six residues (SC/6R), and even long-pass
probabilistic models. Therefore, it has been suggested to employ biophysical–computational
approaches that can determine the kinetics and thermodynamics of the
translocation. In this sense, and based on the apparent inconsistency
between structural and functional studies, we propose to apply biophysical
approaches based on elastic network models (ENM) to study the intrinsic
dynamics of the theoretically most probable hydrolysis mechanism.
The proposed models ENM suggest that the ClpP region is decisive for
the stabilization of the ClpXP complex, contributing to the flexibility
of the residues adjacent to the pore, favoring the increase in pore
size and, therefore, with the energy of interaction of its residues
with a larger portion of the substrate. It is predicted that the complex
may undergo a stable configurational change once assembled and that
the deformability of the system once assembled is oriented, to increase
the rigidity of the domains of each region (ClpP and ClpX) and to
gain flexibility of the pore. Our predictions could suggest under
the conditions of this study the mechanism of the interaction of the
system, of which the substrate passes through the unfolding of the
pore in parallel with a folding of the bottleneck. The variations
in the distance calculated by molecular dynamics could allow the passage
of a substrate with a size equivalent to ∼3 residues. The theoretical
behavior of the pore and the stability and energy of binding to the
substrate based on ENM models suggest that in this system, there are
thermodynamic, structural, and configurational conditions that allow
a possible translocation mechanism that is not strictly sequential.