Engineering in the (Bio)Material World:
Overcoming the Natural Limitations of Biocatalysis

Professor Douglas S. Clark
University of California Berkeley
Department of Chemical Engineering

Date: Thursday, Oct. 19, 2006
Time: 4:00 p.m.
Place: Engineering II, Room 3361

ABSTRACT

The utility of enzymes as practical catalysts has increased greatly in recent years. Advances in enzyme immobilization, nonaqueous enzymology, and protein engineering, along with expanded sourcing of enzymes from extremophiles (organisms that thrive under immoderate conditions), have established that enzymes can function over a much broader range of conditions than was previously thought possible. Improving the versatility and robustness of enzymes is crucial for expanding the utility of biocatalysis in applications ranging from large-scale bioprocesses to nano-scale biodevices.

This presentation will highlight recent progress from our laboratory toward the development of biocatalysts and biocatalytic materials with exceptionally high activity and/or stability under extreme conditions and in unconventional reaction media. Specific topics of current interest include biocatalyst engineering for nonaqueous solvent systems, materials development for microscale biocatalysis, and practical exploitation of extremophilic adaptation systems.

With regard to extremophiles, these organisms epitomize the limits of biodiversity, and represent a vast but still largely untapped source of new bioproducts and biomaterials. Extremophiles have now been isolated from, or have at least been linked with, some of the harshest environments on Earth. Methanocaldococcus jannaschii , a hyperthermophilic methanarchaeon , is one such organism. Among other promising discoveries, we have found that a stress-induced chaperone from M. jannaschii assembles into homo-multimeric, remarkably stable filaments up to 2 m m in length. These chaperone filaments appear to be well-suited for the folding and stabilization of proteins in extremis and for the development of custom-designed nanowires and nanostructured functional materials.