bm6b01759_si_001.pdf (867.06 kB)
Phase Behavior and Self-Assembly of Perfectly Sequence-Defined and Monodisperse Multiblock Copolypeptides
journal contribution
posted on 2017-01-17, 00:00 authored by Sarah
R. MacEwan, Isaac Weitzhandler, Ingo Hoffmann, Jan Genzer, Michael Gradzielski, Ashutosh ChilkotiThis paper investigates
how the properties of multiblock copolypeptides
can be tuned by their block architecture, defined by the size and
distribution of blocks along the polymer chain. These parameters were
explored by the precise, genetically encoded synthesis of recombinant
elastin-like polypeptides (ELPs). A family of ELPs was synthesized
in which the composition and length were conserved while the block
length and distribution were varied, thus creating 11 ELPs with unique
block architectures. To our knowledge, these polymers are unprecedented
in their intricately and precisely varied architectures. ELPs exhibit
lower critical solution temperature (LCST) behavior and micellar self-assembly,
both of which impart easily measured physicochemical properties to
the copolymers, providing insight into polymer hydrophobicity and
self-assembly into higher order structures, as a function of solution
temperature. Even subtle variation in block architecture changed the
LCST phase behavior and morphology of these ELPs, measured by their
temperature-triggered phase transition and nanoscale self-assembly.
Size and morphology of polypeptide micelles could be tuned solely
by controlling the block architecture, thus demonstrating that when
sequence can be precisely controlled, nanoscale self-assembly of polypeptides
can be modulated by block architecture.