Hydration and Conformational Mechanics of Single, End-Tethered Elastin-like Polypeptides

TitleHydration and Conformational Mechanics of Single, End-Tethered Elastin-like Polypeptides
Publication TypeJournal Article
Year of Publication2008
AuthorsValiaev, A, Lim, DW, Schmidler, S, Clark, RL, Chilkoti, A, Zauscher, S
JournalJournal of the American Chemical Society
Volume130
Issue33
Pagination10939 - 10946
Date Published08/2008
ISSN1520-5126
Abstract

We investigated the effect of temperature, ionic strength, solvent polarity, and type of guest residue on the force−extension behavior of single, end-tethered elastin-like polypeptides (ELPs), using single molecule force spectroscopy (SMFS). ELPs are stimulus-responsive polypeptides that contain repeats of the five amino acids Val-Pro-Gly-Xaa-Gly (VPGXG), where Xaa is a guest residue that can be any amino acid with the exception of proline. We fitted the force−extension data with a freely jointed chain (FJC) model which allowed us to resolve small differences in the effective Kuhn segment length distributions that largely arise from differences in the hydrophobic hydration behavior of ELP. Our results agree qualitatively with predictions from recent molecular dynamics simulations and demonstrate that hydrophobic hydration modulates the molecular elasticity for ELPs. Furthermore, our results show that SMFS, when combined with our approach for data analysis, can be used to study the subtleties of polypeptide−water interactions and thus provides a basis for the study of hydrophobic hydration in intrinsically unstructured biomacromolecules.

DOI10.1021/ja800502h
Short TitleJ. Am. Chem. Soc.
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