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Biomolecular Tools for Sustainable Energy and Improved Human Health

Speaker: Wilfred Chen, University of Delaware
Series: CBE Departmental Seminars
Location: Elgin Room (E-Quad A224)
Date/Time: Wednesday, September 26, 2012, 4:00 p.m. - 5:00 p.m.

The complex interactions between humans and the rest of the biosphere have created some of our most challenging global problems in human history such as energy sustainability, severe pollutions, and emergence or re-emergence of old and new epidemics and diseases. Thus, there is an urgent need for new technologies to tackle these challenging global problems. In this talk, I will describe our recent efforts in addressing two key global problems in biofuel production and virus infection. 

Cellulosomes are cellulolytic complexes found in many anaerobic microorganisms and have been shown to degrade cellulose efficiently. The major component of these macromolecule complexes is a structural scaffoldin consisting of repeating cohesin domains, which are docked individually with a cellulase tagged dockerin domain. The specific cohesin-dockerin interaction provides the mechanism for position-specific self-assembly. To emulate the success of a natural mechanism for efficient cellulose hydrolysis, a mini-cellulosome is assembled onto the yeast cell surface, enabling the ethanol-producing strain to utilize cellulose and concomitantly ferment it to ethanol. More importantly, by organizing these cellulases in an ordered structure, the enhanced synergy will increase the efficiency in cellulose and hydrolysis and ethanol production.

The ability to detect infectious viruses is of critical importance in medical diagnostic and environmental/agricultural protection. Current methods to assess the presence of infectious viruses are based on mammalian cell culture and rely on the production of visible cytopathic effects (CPE). Depending on the specific virus type and concentration in the sample, it may take several days or weeks for CPE to appear. In this talk, I will discuss several FRET-based approaches recently developed in my lab for real-time monitoring of viral infection. Quantum dot-based molecular probes were designed to detect the presence of viral RNAs or proteases as an indicator of viral infection. For intracellular delivery, a cell-penetrating TAT peptide was appended to the probes to enable real-time monitoring of viral infection in living cells. Fluorescence microscopy and flow cytometry were used to directly visualize infected cells and to subsequently follow virus spread in situ. As an added benefit, the specific nature of these probes also enables their utility as a sensitive agent for viral inhibitors discovery. Some progress in this area will be discussed.