Virtual Seminar"Topologically Active Polymers"Davide Michieletto

Micro/Bio/Nanofluidics (Shen) Unit would like to invite you to the virtual seminar by
Dr. Davide Michieletto on January 24 (Monday).

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Date: Monday, January 24, 2022
Time: 17:00-18:00
**Zoom session
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Join Zoom Meeting
https://oist.zoom.us/j/99520392195?pwd=Yjc2b1JpQUlzbmxpc0hDMEdtcFlWQT09

Meeting ID: 995 2039 2195
Passcode: 326496

Speaker:

Dr. Davide Michieletto
Royal Society University Research Fellow
School of Physics and Astronomy & Institute of Genetics and Cancer University of Edinburgh in UK

Title:

Topologically Active Polymers

Abstract:

Polymer physics successfully describes most of the polymeric materials that we encounter everyday. In spite of this, it heavily relies on the assumption that polymers do not change topology (or architecture) in time or that, if they do alter their morphology, they do so in equilibrium.
This assumption spectacularly fails for DNA in vivo, which is constantly topologically re-arranged by ATP-consuming proteins within the cell nucleus.
Inspired by this, here I propose to study entangled systems of DNA which can selectively alter their topology and architecture in time and may expend energy to do so. I argue that solutions of topologically active (living) polymers can display unconventional viscoelastic behaviours and can be conveniently realised using solutions of DNA functionalised by certain families of vitally important proteins.
In this talk I will present some results on the microrheology of entangled DNA undergoing digestion by restriction enzymes and ligation by T4 ligase.  
I will present theories, simulations and experiments using particle tracking microrheology showing that that we can harness this non-equilibrium process to yield time-varying viscoelastic behaviours.

Host:

Prof. Amy Shen