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Theoretical Physics of Living Matter Seminar: 
Synthetic cell membrane mimics interacting with living matter 


Anfang
10.12.2020 11:00 Uhr
Veranstaltungsort
Remote access

Cesar Rodriguez-Emmenegger

DWI — Leibniz Institute for Interactive Materials

Forckenbeckstraße 50, 52074 Aachen, Germany

Join us at: www.fz-juelich.de/ibi/TPLMSem

Biological membranes interact with their environment in a very complex manner and can discriminate between almost identical cells or proteins even at extremely low concertation. These interactions are superselective, i.e. the binding is specific, occurs only above a certain threshold density of receptors, and increases supralinear with their density. In our work, we address the question:

Theoretical Physics

How can artificial superselectivity be accomplished in synthetic cell membrane mimics? Not only is this important to expand the understanding of biological systems, but also to develop synthetic protocells with life-like functions. I will introduce our concept for superselectivity in synthetic cell membranes which requires the integration of (i) specificity, (ii) multivalency (to enhance binding but retain reversibility), (iii) 2D dimensional organization of receptors, and (iv) concepts of cooperativity in binding. To tackle this question, my team has designed and synthesized new families of amphiphiles —comb-polymers and Janus dendrimers— that self-assemble into cell-mimetic vesicles. Although these molecules do not exist in nature, the vesicles closely mimic the thickness, flexibility, and lateral 2D organization of cell membranes.

These properties are precisely encoded in the chemical structure, architecture, and topology of the macromolecular building blocks of the membrane. As an example, I will show our recent work where we discovered that the reactivity of sugar receptors towards lectins is enhanced by the 2D organization of sugars into nanoarrays (clustering) and raft-mimics (cooperativity) on the periphery of protocells. Furthermore, this talk will show how to introduce life-like functions such as endocytosis of living bacteria or remodeling of membranes without involving active cell machinery.


Kontakt

Dr. Dmitry Fedosov
Telefon: +49 2461 61-2972
Fax: +49 2461 61-3180
E-Mail: d.fedosov@fz-juelich.de