title: Unexpected multivalent display of proteins by temperature triggered self-assembly of elastin-like polypeptide block copolymers.
abstract: We report herein the unexpected temperature triggered self-assembly of proteins fused to thermally responsive elastin-like polypeptides (ELPs) into spherical micelles. A set of six ELP block copolymers (ELP(BC)) differing in hydrophilic and hydrophobic block lengths were genetically fused to two single domain proteins, thioredoxin (Trx) and a fibronectin type III domain (Fn3) that binds the α(v)β(3) integrin. The self-assembly of these protein-ELP(BC) fusions as a function of temperature was investigated by UV spectroscopy, light scattering, and cryo-TEM. Self-assembly of the ELP(BC) was unexpectedly retained upon fusion to the two proteins, resulting in the formation of spherical micelles with a hydrodynamic radius that ranged from 24 to 37 nm, depending on the protein and ELP(BC). Cryo-TEM images confirmed the formation of spherical particles with a size that was consistent with that measured by light scattering. The bioactivity of Fn3 was retained when presented by the ELP(BC) micelles, as indicated by the enhanced uptake of the Fn3-decorated ELP(BC) micelles in comparison to the unimer by cells that overexpress the α(v)β(3) integrin. The fusion of single domain proteins to ELP(BC)s may provide a ubiquitous platform for the multivalent presentation of proteins.
authors.affiliation: Department of Biomedical Engineering, Duke University, Durham, North Carolina 27708, USA.
authors.forename: Wafa
authors.initials: W
authors.lastname: Hassouneh
authors.forename: Karl
authors.initials: K
authors.lastname: Fischer
authors.forename: Sarah R
authors.initials: SR
authors.lastname: MacEwan
authors.forename: Robert
authors.initials: R
authors.lastname: Branscheid
authors.forename: Chuan Lawrence
authors.initials: CL
authors.lastname: Fu
authors.forename: Rihe
authors.initials: R
authors.lastname: Liu
authors.forename: Manfred
authors.initials: M
authors.lastname: Schmidt
authors.forename: Ashutosh
authors.initials: A
authors.lastname: Chilkoti
mesh_terms: D004549:Elastin / Q000737:chemistry / Q000235:genetics / Q000493:pharmacokinetics; D005353:Fibronectins / Q000737:chemistry* / Q000378:metabolism; D006801:Humans; D057927:Hydrophobic and Hydrophilic Interactions; D020014:K562 Cells; D008823:Micelles; D008958:Models, Molecular; D010316:Particle Size; D010455:Peptides / Q000737:chemistry* / Q000235:genetics / Q000493:pharmacokinetics; D013696:Temperature; D013879:Thioredoxins / Q000737:chemistry* / Q000378:metabolism; D014407:Tumor Cells, Cultured
chemical_list: D005353:Fibronectins; D008823:Micelles; D010455:Peptides; D013879:Thioredoxins; D004549:Elastin