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Liposomes, Exosomes, and Virosomes: From Modeling Complex
Membrane Processes to Medical Diagnostics and Drug Delivery
Poster Abstracts
75
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.