Abstract:
:We study the folding of small proteins inside confining potentials. Proteins are described using an effective potential model that contains the Ramachandran angles as degrees of freedom and does not need any a priori information about the native state. Hydrogen bonds, dipole-dipole-, and hydrophobic interactions are taken explicitly into account. An interesting feature displayed by this potential is the presence of metastable intermediates between the unfolded and native states. We consider different types of confining potentials to describe proteins folding inside cages with repulsive or attractive walls. Using the Wang-Landau algorithm, we determine the density of states and analyze in detail the thermodynamical properties of the confined proteins for different sizes of the cages. We show that confinement dramatically reduces the phase space available to the protein and that the presence of intermediate states can be controlled by varying the properties of the confining potential. Cages with strongly attractive walls destabilize the intermediate states and lead to a two-state folding into a configuration that is less stable than the native structure. However, cages with slightly attractive walls enhance the stability of native structure and induce a folding process, which occurs through intermediate configurations.
journal_name
Biophys Jjournal_title
Biophysical journalauthors
Ojeda P,Garcia ME,Londoño A,Chen NYdoi
10.1529/biophysj.107.125369subject
Has Abstractpub_date
2009-02-01 00:00:00pages
1076-82issue
3eissn
0006-3495issn
1542-0086pii
S0006-3495(08)00010-6journal_volume
96pub_type
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