Dresden 2006 – wissenschaftliches Programm

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PV: Plenarvorträge

PV XIII

PV XIII: Preisträgervortrag

Donnerstag, 30. März 2006, 13:15–14:00, HSZ 01

Life in soft elastic shells — •Erich Sackmann — Professor Emeritus, Physik Department E22, Technische Universität München, Garching, Germany — Träger der Stern-Gerlach-Medaille

Mother nature designed complex biological materials of stunning physical properties. One outstanding example is the cell envelope: a stratified shell composed of multi-component lipid-protein bilayers (the plasma membranes) which is coupled to a quasi-two-dimensional macromolecular scaffold (the actin cortex). A hierarchical design enables this composite elastic shell to control numerous fundamental life processes. These range from fundamental biochemical reactions such as ATP production in electron transfer chains over the amplification of external signals (triggered by hormones or photons) to cell-cell adhesion and cell locomotion.

The lecture deals with the unique elastic properties of the composite cell envelopes and the control of biological membrane processes by mechanical forces. It focuses on two aspects of this rich playground for physicists. First, the control of the molecular architecture and the transient generation of functional machines within plasma membranes by structural phase transitions, phase separation and the elastic properties of the bilayers are discussed. Secondly, I address the physical basis of cell adhesion by complex interplay of specific forces, generic interfacial interactions and adhesion-induced elastic stresses. Here I discuss the amazing analogy of cell adhesion to first order wetting transitions as an example of the control of life processes by the laws of classical physics. A general aim of the lecture is to point out that the precise measurement of physical parameters is a necessity to gain insight into the complex architecture and function of biological materials.