[SCAN] Molecular processes of peptides and proteins at model membranes

SCAN

Title: Molecular processes of peptides and proteins at model membranes

Speaker: Peter Hildebrandt

Affiliation: Technische Universität Berlin

Abstract: Many biological processes involve proteins that are attached to or embedded in membranes. Thus, their reactions are governed by parameters different to those in the solution phase, such as the restricted mobility and the different dielectric properties of the environment. A particularly important factor is the local electric field which in the membrane/solution interface may be as high as 109 V/m. Such high electric fields are likely to affect protein structures and reaction dynamics. 

To elucidate molecular processes at membranes under the action of local electric fields requires appropriate approaches that solely focus on the target protein. Here we employ membrane models on metal electrodes that mimic essential features of the natural templates but lack their complex compositions. Using surface enhanced vibrational spectroscopies, these model membranes allow for monitoring structural changes of membrane-bound proteins as a function of the local electric field, which can be quantified by using the vibrational Stark effect (VSE). The potential of this approach will be illustrated on the basis of proteins either bound to the periphery or integrated into the membrane model. These example proteins exert different functions including electron transfer, redox-linked proton pumping, catalysis, and channel formation.

Finally, it will be shown how this approach may contribute to elucidate the mechanisms of antibiotic peptides.