Statistical coil model of the unfolded state: resolving the reconciliation problem.

ABSTRACT: An unfolded state ensemble is generated by using a self-avoiding statistical coil model that is based on backbone conformational frequencies in a coil library, a subset of the Protein Data Bank. The model reproduces two apparently contradicting behaviors observed in the chemically denatured state for a variety of proteins, random coil scaling of the radius of gyration and the presence of significant amounts of local backbone structure (NMR residual dipolar couplings). The most stretched members of our unfolded ensemble dominate the residual dipolar coupling signal, whereas the uniformity of the sign of the couplings follows from the preponderance of polyproline II and beta conformers in the coil library. Agreement with the NMR data substantially improves when the backbone conformational pr

SUBMITTER: Jha AK 

PROVIDER: S-EPMC1201606 | biostudies-literature | 2005 Sep

REPOSITORIES: biostudies-literature