Application of non-ionic polymers towards the evaluation of membrane pore size
Institutional Repository of Vilnius University, 2017
Online
unknown
Zugriff:
Various model systems are used in order to circumvent the complex analysis of native membranes. One of them is tethered bilayer lipid membranes (tBLMs) which were used in this work. Such membranes formed on atomically flat gold surface, by using the multilayer vesicle fusion method, can be used for investigating membrane proteins and their interaction with the cells membrane. tBLMs were used in this work in order to examine the membrane defects caused by the cholesterol dependent cytolysins (CDCs). The forming of phospholipidic membrane as well as the citolysin inflicted damage were measured using the electrochemical impedance spectroscopy (EIS) method while tracking the changes in the systems electrical parameters. The aim of this work was to expand the potential of EIS by showing that this method can not only detect the bacterial toxins in a very precise and fast way but also provide structural information on the membrane defects. The size variation of CDC formed pores was investigated with the help of nonionic polymers – polyethylene glycols (PEGs) which vary in size. We have shown that two members of the CDC family (vaginolysin (VLY) and pneumolysin (PLY)) have different pore forming mechanisms. We have determined that both citolysins can damage the membrane before fully forming a ring shaped oligomer on the surface of the membrane. Forming small pores is more common to PLY, whereas VLY forms the majority of the pores with a larger diameter and demands PEGs with a bigger molecular mass in order to block the defects. We have also shown that such variation of defect sizes determines a different damage rate between these proteins.
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Application of non-ionic polymers towards the evaluation of membrane pore size
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Autor/in / Beteiligte Person: | Dovydėnas, Donatas ; Valinčius, Gintaras |
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Veröffentlichung: | Institutional Repository of Vilnius University, 2017 |
Medientyp: | unknown |
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