CPB 697 RESEARCH SEMINAR

DEPARTMENT OF COMPARATIVE PATHOBIOLOGY

Feng Xiao, MS

Graduate Student in Molecular Virology

Department of Comparative Pathobiology

Purdue University

“Controllable Switching Of Size And Shape Of Bacterial Virus phi29 Motor Component”

Thursday, April 5, 2007

VPTH 112

3:30 pm

Abstract:

Bacillus subtilis bacteriophage phi29 DNA packaging motor has been investigated for applications as delivery vehicles in nanomedicine or power source in. nanotechnology. This will require modification of motor components to ‘match’ the new environment. The cone-shaped connector protein, one of the essential components of the motor, is a key protein that will require modification for this application. The connector is 13.8nm across at its wide end, 6.6nm at the narrow end, with a 3.6nm central channel through which viral DNA passes into the procapsid and exits during the infection process. Evaluated by transmission electron microscopy, cryo-electron microscopy, glycerol gradient sedimentation, and analytical ultracentrifugation, it was found that the connector formed a 40-nm, compared to the 14-nm wild-type connector, higher order structure regulated by N-terminal modification, or the addition of RNA or DNA. Such constructs and the significant size and structural switching of nanoparticles regulated by peptide, DNA, or RNA  provides intriguing opportunities for controllable design in engineering hybrid for medical or nanotechnological applications.