Quantitative model of the phase behavior of recombinant pH-responsive elastin-like polypeptides.
Abstract
Quantitative models are required to engineer biomaterials with environmentally responsive
properties. With this goal in mind, we developed a model that describes the pH-dependent
phase behavior of a class of stimulus responsive elastin-like polypeptides (ELPs)
that undergo reversible phase separation in response to their solution environment.
Under isothermal conditions, charged ELPs can undergo phase separation when their
charge is neutralized. Optimization of this behavior has been challenging because
the pH at which they phase separate, pHt, depends on their composition, molecular
weight, concentration, and temperature. To address this problem, we developed a quantitative
model to describe the phase behavior of charged ELPs that uses the Henderson-Hasselbalch
relationship to describe the effect of side-chain ionization on the phase-transition
temperature of an ELP. The model was validated with pH-responsive ELPs that contained
either acidic (Glu) or basic (His) residues. The phase separation of both ELPs fit
this model across a range of pH. These results have important implications for applications
of pH-responsive ELPs because they provide a quantitative model for the rational design
of pH-responsive polypeptides whose transition can be triggered at a specified pH.
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Journal articlePermalink
https://hdl.handle.net/10161/4020Published Version (Please cite this version)
10.1021/bm100571jPublication Info
Mackay, J Andrew; Callahan, Daniel J; Fitzgerald, Kelly N; & Chilkoti, Ashutosh (2010). Quantitative model of the phase behavior of recombinant pH-responsive elastin-like
polypeptides. Biomacromolecules, 11(11). pp. 2873-2879. 10.1021/bm100571j. Retrieved from https://hdl.handle.net/10161/4020.This is constructed from limited available data and may be imprecise. To cite this
article, please review & use the official citation provided by the journal.
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Ashutosh Chilkoti
Alan L. Kaganov Distinguished Professor of Biomedical Engineering
Ashutosh Chilkoti is the Alan L. Kaganov Professor of Biomedical Engineering and Chair
of the Department of Biomedical Engineering at Duke University.
My research in biomolecular engineering and biointerface science focuses on the development
of new molecular tools and technologies that borrow from molecular biology, protein
engineering, polymer chemistry and surface science that we then exploit for the development
of applications that span the range from bioseparations, plasmonic bio

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