Predicting Transition Temperatures of Elastin-Like Polypeptide Fusion Proteins

TitlePredicting Transition Temperatures of Elastin-Like Polypeptide Fusion Proteins
Publication TypeJournal Article
Year of Publication2013
AuthorsChristensen, T, Hassouneh, W, Trabbic-Carlson, KA, Chilkoti, A
JournalBiomacromolecules
Volume14
Issue5
Pagination1514–1519
Date Published03/2013
ISSN1526-4602
Abstract

Elastin-like polypeptides (ELPs) are thermally sensitive peptide polymers that undergo thermally triggered phase separation and this behavior is imparted to soluble proteins when they are fused to an ELP. The transition temperature of the ELP fusion protein is observed to be different than that of a free ELP indicating that the surface properties of the fused protein modulate the thermal behavior of ELPs. Understanding this effect is important for the rational design of applications that exploit the phase transition behavior of ELP fusion proteins. We had previously developed a biophysical model that explained the effect of hydrophobic proteins on depressing the transition temperature of ELP fusion proteins relative to free ELP. Here, we extend the model to elucidate the effect of hydrophilic proteins on the thermal behavior of ELP fusion proteins. A linear correlation was found between overall accessible surface residue composition of a protein weighted by a characteristic transition temperature for that residue and the difference in transition temperatures between the ELP protein fusion and the corresponding free ELP. In breaking down the contribution of residues to polar, non-polar and charged, the model revealed that charged residues are the most important parameter in altering the transition temperature of an ELP fusion relative to the free ELP.

DOI10.1021/bm400167h
Short TitleBiomacromolecules