Aaron Blanchard

BME PhD Defense Presentation

Date: July 23rd, 2020

Time: 9:00-11:00am

Location: https://emory.zoom.us/j/5365547531

Committee Members:

Khalid Salaita, PhD (Emory University, Chemistry) (Advisor)

Todd Sulchek, PhD (Georgia Institute of Technology, School of Mechanical Engineering)

Yonggang Ke, PhD (Emory University, Biomedical Engineering)

Eric Weeks, PhD (Emory University, Physics)

Keir Neuman, PhD (National Institute of Health)

Title: DNA mechanotechnology for sensing and generating piconewton scale mechanical forces

Abstract:

Mechanical systems are composed of force-generating motors, force sensors, and load-bearing structures. Macro- and micro-scale mechanical systems have revolutionized human civilization, and nanoscale mechanical systems have similar potential. DNA nanotechnology, a unique platform for the self-assembly of complex nanostructures, offers unprecedented capacity to design the components of nanoscale mechanical systems. Today, mechanical DNA devices are playing increasingly critical roles in molecular biophysics, immunology, regenerative medicine, materials science, and nanorobotics.

As a student in Dr. Khalid Salaita’s lab, I have spent my PhD developing and studying DNA-based devices that generate and/or sense piconewton (pN)-scale molecular forces. This research area, which we named “DNA mechanotechnology”, has recently emerged at the intersection of DNA nanotechnology and mechanobiology. As such, much of my work centers around quantitative biophysical modeling of biomolecules under mechanical force. Using this approach, I helped develop the world’s most powerful DNA-based motor, which can generate ~100-150 pN of force as it translocates (compared to ~0.02 pN of previous motors) and developed computational models for studying this novel mechanism of force-generation. I will present my findings of the force generating capacity of these motors, as well as the properties that control their speed and force. In addition, I have also helped develop DNA-based tension probes that emit fluorescence when pulled on by individual cell-surface receptors. I will present fluorescence polarization-based methods for using the molecular tension probes to measure the orientation of molecular forces.