Geometrical assembly of ultrastable protein templates for nanomaterials

Abstract

The fabrication of nanoscale devices requires architectural templates on which to position functional molecules in complex arrangements. Protein scaffolds are particularly promising templates for nanomaterials due to inherent molecular recognition and self-assembly capabilities combined with genetically encoded functionalities. However, difficulties in engineering protein quaternary structure into stable and well-ordered shapes have hampered progress. Here we report the development of an ultrastable biomolecular construction kit for the assembly of filamentous proteins into geometrically defined templates of controllable size and symmetry. The strategy combines redesign of protein–protein interaction specificity with the creation of tunable connector proteins that govern the assembly and projection angles of the filaments. The functionality of these nanoarchitectures is illustrated by incorporation of nanoparticles at specific locations and orientations to create hybrid materials such as conductive nanowires. These new structural components facilitate the manufacturing of nanomaterials with diverse shapes and functional properties over a wide range of processing conditions.

Protein Calligraphy: A New Concept Begins To Take Shape

“…Furthermore, the addition of a trimerization domain into one of the engineered subunits enabled the creation of a three-way connector that assembles with filaments containing the opposing helical sequence into geometrically ordered shapes such as pinwheels ( Figure 1 ). These protein shapes were ideal templates for building nanomaterials that included highly conductive nanowires, 36 and demonstrate that the calligraphy of proteins is maturing beyond the proof of principle stage and moving toward application in solving a host of challenging problems.…”

“… 35 Our recent paper demonstrated that the natural protein–protein interface of a filamentous protein can be redesigned using coiled coils to impart specificity and drive filament assembly into multifaceted structures. 36 In this approach, modular connector proteins were created by replacing one of the two contact interfaces in the filament subunit with opposing helical domains that associate together as tight heterodimeric coiled coils ( Figure 2 B). The resulting pair of connector proteins bound to each other with high specificity while also incorporating into nascent filaments.…”

Protein-Mediated Biotemplating on the Nanoscale

“…A recent contribution by Clark et al [54] offers a promising “ultrastable biomolecular construction kit for the assembly of filamentous proteins into geometrically defined templates of controllable size and symmetry”. The kit is based on the filamentous protein γ-prefoldin derived from the hyperthermophile Methanocaldococcus jannaschii , and its use as the major component of a biotemplate has been constructed in combination with other protein-made connecting units (see also Slocik et al [45]).…”

Bottom-up synthesis of protein-based nanomaterials from engineered β-solenoid proteins

“…The naturally filament-forming protein γ-prefoldin has been used to engineer self-assembling protein filaments that can be functionalized. [33] Impressive examples of non-fibrous protein-based materials have been engineered recently. [34][35][36] Here, a flexible alternative for engineering protein fibril-based nanoscale scaffolds under mild conditions, based on β-solenoid protein (BSPs), is discussed.…”