The lateral distribution of membrane constituents in the membrane is determined by the minimum of the membrane free energy. Each molecule contributes to the energy by reflecting the mismatch between the intrinsic curvature of the molecule and the local membrane curvature at the site of the molecule. In the chapter published in the monography, experiments which show lateral seggregation of membrane constituents and the corresponding theoretical description were presented, with special emphasis on the original contrinution - the role of in-plane orientational ordering of membrane constituents.
COBISS.SI-ID: 22771929
In membrane budding, a thin neck is formed, which connects the bud with the mother cell. Since membrane constituents are more or less laterally mobile, molecules exhibit lateral redistribution in such way that their energy is minimal. In the neck, accumulation of molecules which favor saddle-like membrane shape takes place. Such molecules are anisotropic with respect to the membrane normal and their energy depends on the in-plane orientation. We have shown that anisotropic molecules accumulate in the thin neck where they exhibit orientational ordering and thereby stabilize the neck.
COBISS.SI-ID: 5752660
We have shown experimentally that adding molecules of a certain species to the suspension of giant phospholipid vesicles causes adhesion of vesicles to each other. We have observed that in the process of budding, such mediated interaction can cause adhesion of the bud to the mother membrane . So the budding does not end with pinching off the vesicle. Based on these results we have proposed a hypothesis that in a similar in vivo process the plasma proteins mediate attractive interaction between membranes which supresses microvesiculation and therefore plays an anticoagulant role.
COBISS.SI-ID: 23283161
Plasma proteins can mediate attractive interaction between the membrane of the bud and of the mother cell and thereby prevent microvesiculation. We have isolated microvesicles from the peripheral blood of healthy volunteers and determined concentration of microvesices while their plasma was added to giant phospholipid vesicles and adhesion was assessed. We have found a negative correlation between the concentration of microvesicles and the effect of adhesion. This result is in favor of the proposed hypothesis (issue 3).
COBISS.SI-ID: 23693785
We have shown that nanotubular connections exist between urothelial cells, where we have distinguished between two types of nanotubes regarding their composition and function. The same theory which explained the stability of thin necks (issue 2), based on the orientational ordering of membrane constituents, also explained the stability of nanotubes.
COBISS.SI-ID: 24674009