Noncanonical self-assembly of highly asymmetric genetically encoded polypeptide amphiphiles into cylindrical micelles.

Journal Article

Elastin-like polypeptides (ELPs) are a class of biopolymers consisting of the pentameric repeat (VPGαG)n based on the sequence of mammalian tropoelastin that display a thermally induced soluble-to-insoluble phase transition in aqueous solution. We have discovered a remarkably simple approach to driving the spontaneous self-assembly of high molecular weight ELPs into nanostructures by genetically fusing a short 1.5 kDa (XGy)z assembly domain to one end of the ELP. Classical theories of self-assembly based on the geometric mass balance of hydrophilic and hydrophobic block copolymers suggest that these highly asymmetric polypeptides should form spherical micelles. Surprisingly, when sufficiently hydrophobic amino acids (X) are presented in a periodic sequence such as (FGG)8 or (YG)8, these highly asymmetric polypeptides self-assemble into cylindrical micelles whose length can be tuned by the sequence of the morphogenic tag. These nanostructures were characterized by light scattering, tunable resistive pulse sensing, fluorescence spectrophotometry, and thermal turbidimetry, as well as by cryogenic transmission electron microscopy (cryo-TEM) and small-angle neutron scattering (SANS). These short assembly domains provide a facile strategy to control the size, shape, and stability of stimuli responsive polypeptide nanostructures.

Full Text

Duke Authors

Cited Authors

  • McDaniel, JR; Weitzhandler, I; Prevost, S; Vargo, KB; Appavou, M-S; Hammer, DA; Gradzielski, M; Chilkoti, A

Published Date

  • November 2014

Published In

Volume / Issue

  • 14 / 11

Start / End Page

  • 6590 - 6598

PubMed ID

  • 25268037

Electronic International Standard Serial Number (EISSN)

  • 1530-6992

International Standard Serial Number (ISSN)

  • 1530-6984

Digital Object Identifier (DOI)

  • 10.1021/nl503221p

Language

  • eng