Aaron Blanchard

BME PhD Proposal Presentation

Date: July 2nd, 2019

Time: 9:00-11:00am

Location: Atwood 360 (Emory)

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: Highly polyvalent DNA motors for molecular detection and nanorobotics

Abstract:

Molecular motors such as kinesin and myosin are ubiquitous in eukaryotes and power countless processes including muscle contraction, embryogenesis, and wound closure. The ability to engineer synthetic molecular motors that mirror the functions of biological motors will be an important step in the development of active and responsive materials of the future. DNA-based walking motors, which use DNA “feet” to translocate across molecular tracks, are the most promising synthetic analogues of molecular motors because they recapitulate the processive stepping behavior of biological motors. However, conventional DNA walkers translocate at speeds and forces that are orders of magnitude lower than biological motors. We have demonstrated progress towards addressing this limitation by developing highly polyvalent DNA motors (HPDMs), which simultaneously use thousands of DNA feet to reach speeds as high as 10 micrometers per minute and generate forces as high as 150 piconewtons, comparable to biological motors.

We achieve high polyvalency by attaching DNA feet to microspheres five-micrometers in diameter. While we propose to leverage this relatively large size to perform molecular detection using a cellphone microscope (Aim 1), the current size prevents applications at the nanoscale. We predict that we can reduce HPDM volume 2,000-fold without substantially reducing speed or force by conjugating DNA feet to rod-shaped, rather than spherical, particles (Aim 2). We also aim to control HPDM motion to perform massively parallel nanolithography (Aim 3). This work will help pave the way for next-generation active and responsive materials and, as such, will be accompanied by detailed observational studies and computational and theoretical modeling (Aim 4) that will help to elucidate the fundamental scaling properties of HPDMs and similar motors.