Biophysical Society Thematic Meeting | Ascona, Switzerland

Liposomes, Exosomes, and Virosomes: From Modeling Complex Membrane Processes to Medical Diagnostics and Drug Delivery

Poster Abstracts

5-POS Board 3 Influence of Composition and Charge of Phospholipid Membranes on the Conformational State of a Protein: A Case of Apomyoglobin Vitalii Balobanov , Nelly Ilyina, Natalia Katina, Ivan Kashparov, Valentina Bychkova. Institute of protein research RAS, Pushchino, Russian Federation. Investigation of protein-membrane interaction is very important for understanding of many aspects of protein life. This is evident for insertion of proteins into membranes or their translocation across membranes, and also for functioning proteins or involvement them into toxic action of amyloid structures in the cell. It was found that negatively charged phospholipids influence significantly on the protein structure. Thus, it is critical to estimate what conditions promote these interactions. In this work influence of negatively charged phospholipid membranes and ratio of protein-to-phospholipid concentrations on kinetics of protein-membrane interaction is studied. Apomyoglobin which properties are well studied was used as an example. Conformational states of the protein were tested by tryptophan fluorescence and far UV circular dichroism spectra. It is shown that in the range of the protein-phospholipid concentrations ratios of 5-20% substantial acceleration of protein-membrane interaction was observed, while in the range of 20-100 % negatively charged phospholipids the effect is practically similar. Below 5% content of negatively charged phospholipids in membrane the process of protein-membrane interactions sharply slows down. The rate of this interaction also depends on the protein structure stability. The importance of the obtained results for understanding of influence of membrane surfaces on the conformational state of proteins, on the folding of membrane proteins and their role in the protein aggregates toxicity is discussed. Static experiments was supported by the MCB program of RAS. Studying kinetic of interaction was supported by the Russian Scientific Foundation.

75