Allosteric actuation of inverse phase transition of a stimulus-responsive fusion polypeptide by ligand binding.

ABSTRACT: We report herein a biopolymer actuator with a modular design that allosterically transduces ligand binding into an aqueous demixing phase transition. The biopolymer actuator consists of two modular domains: a ligand binding protein domain, calmodulin (CaM), that is fused to a transducer domain, a stimulus-responsive elastin-like polypeptide (ELP) that exhibits a reversible lower critical solution temperature (LCST) phase transition. We demonstrate that binding of calcium to CaM spontaneously triggers the phase transition of the attached ELP, leading to formation of meso-microscale particles depending on the chain length of the ELP. This behavior is reversible as chelation of the bound calcium results in dissolution of the assembled particles, is selective for calcium as opposed to magnesiu

SUBMITTER: Kim B 

PROVIDER: S-EPMC2648868 | biostudies-literature | 2008 Dec

REPOSITORIES: biostudies-literature