Self-Assembly of Synthetic and Biological Polymeric Systems of ...

eorganization as a consequence of inter-residue contact (including both native and non
native-like interactions) of these compact states may involve high-energy barriers, leading to
the transient population of partially intermediate states. Such species can be either productive
for on-pathway folding until reaching the native state; or they can be trapped in such a manner
that the native structure cannot be reached without substantial organizational events (off-
pathway).
5.2.3.- Native state
Currently, it is known that the conformational states of proteins are structural dynamic
processes, i.e. even at native conditions, structured proteins have access to a manifold of near-
native conformations, in which protein native structures show fluctuations around the minimal
energy conformation (100). Such structural movements are essential in order to encompass
their function, such as enzyme catalysis or ligand binding, as well as site-to site communication
within the globular protein fold or between proteins subunits.
Figure 5.3 Schematic illustration of the energy landscape for protein folding and aggregation.
a) The surface illustrates the roughness of the protein landscape, showing the multitude of
conformational states available to a polypeptide chain. The conformational search of a single
polypeptide chain to a functional monomer can be described in a simple folding funnel (light
grey), intermolecular association increased the roughness of the energy landscape (dark grey),
b) Proposed pathways related to the conformational states shown in a) populated on the
combined folding and aggregation energy landscape (97).
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