Framework-directed self assembly
Researchers have amassed a wonderful collection of functional, atomically precise components with potentially useful properties — optical, electronic, chemical, mechanical, and so on — but they haven’t been assembled to make complex, atomically precise nanosystems. I think of this as the “circuit-board problem”: Functional devices are small, simple, and may have interesting physics, but they aren’t much use as system components until they are integrated with a big, complex framework that can organize them and hold them together.
The concept of “modular molecular composite nanosystems” (MMCS) describes an approach to building complex, self-assembled structures that can organize functional components. The idea is to exploit the properties of structural DNA nanotechnology (in particular, DNA origami [pdf]) to provide an easy-to-design framework, together with complementary properties of folded polymeric molecular objects (“foldamers”, and in particular, products of protein engineering) to bind and organize functional components in precise 2- and 3-D configurations. This idea has gotten a very positive response in the DNA and protein engineering communities, in part because it offers an extended rationale for ideas that some researchers (for example, Thom LaBean and coworkers) have already taken as far as proof-of-principle demonstrations.
The table above outlines the complementary properties of structural DNA, engineered proteins, and special functional structures. I’ve been giving talks on this for a while now, and the report from the Battelle-led Roadmap project explores this concept in more detail, and I will be returning to it in later posts.
- A Revolution in de novo Protein Engineering Methodology
- A Third Revolution in DNA Nanotechnology
- Macromolecular Modeling for Molecular Systems Engineering