Exploiting biocatalysis in peptide self-assembly.

This review article covers recent developments in the use of enzyme-catalyzed reactions to control molecular self-assembly (SA), an area that merges the advantages of biocatalysis with soft materials self-assembly. This approach is attractive because it combines biological (chemo-, regio-, and enantio-) selectivity with the versatility of bottom up nanofabrication through dynamic SA. We define enzyme-assisted SA (e-SA) as the production of molecular building blocks from nonassembling precursors via enzymatic catalysis, where molecular building blocks form ordered structures via noncovalent interactions. The molecular design of SA precursors is discussed in terms of three key components related to (i) enzyme recognition, (ii) molecular switching mechanisms, and (iii) supramolecular interactions that underpin SA. This is followed by a discussion of a number of unique features of these systems, including spatiotemporal control of nucleation and structure growth, the possibility of controlling mechanical properties and the defect correcting and component selecting capabilities of systems that operate under thermodynamic control. Applications in biomedicine (biosensing, controlled release, matrices for wound healing, controlling cell fate by gelation) and bio(nano)technology (biocatalysts immobilization, nanofabrication, templating, and intracellular imaging) are discussed. Overall, e-SA allows for unprecedented control over SA processes and provides a step forward toward production of nanostructures of higher complexity and with fewer defects as desired for next generation nanomaterials. (c) 2010 Wiley Periodicals, Inc.