Mechanics and dynamics of triglyceride-phospholipid model membranes: Implications for cellular properties and function

Abstract

We demonstrate here that triolein alters the mechanical properties of phospholipid membranes and induces extraordinary conformational dynamics. Triolein containing membranes exhibit fluctuations up to size range of 100μm and with the help of these are e.g. able to squeeze through narrow passages between neighbouring structures. Triolein-phosphatidylcholine membranes were found to have bending rigidity significantly lower than that of corresponding pure phosphatidylcholine membrane. Moreover, the triolein containing membranes were found to be reluctant to fuse, which is in good accordance with larger lamellar distances observed in the TOPOPC membranes. These findings suggest repulsion between adjacent membranes. We provide a comprehensive discussion on the possible explanations for the observed mechanics and dynamics in the TOPOPC system and on their potential cellular implications.

Fat inclusions strongly alter membrane mechanics

“…Finally, we determined the bending rigidity (K) by nanotube pulling experiments (Figure 4D and S4E-I). We found that the presence of triolein in a PC GUV bilayer decreased the bending rigidity (12 ± 4 kBT) roughly by a factor of two compared to the value for a bare GUV (21 ± 4 kBT) (Figure 4E); a similar trend was found when measuring the rigidity by fluctuation analysis (42). Surprisingly, squalene slightly increased the bending rigidity (27 ± kBT), illustrating that oil molecules do not necessarily change membrane properties in the same way.…”

Determinants of HDL Cholesterol Efflux Capacity after Virgin Olive Oil Ingestion: Interrelationships with Fluidity of HDL Monolayer

“…Lipoprotein oxidation promotes the linkage between fatty acids reducing the mobility of the chains which increases the rigidity of the lipid monolayer . In turn, the fluidity of the HDL monolayer influences ApoA‐I conformation and binding to HDL . Thus, a close interrelationship exists between HDL oxidative status, ApoA‐I, and HDL fluidity, the three main factors which appear related to CEC in our study.…”

Porcine Hepatic Response to Fumonisin B1 in a Short Exposure Period: Fatty Acid Profile and Clinical Investigations

“…Similar to PL results, the omega-6:omega-3 ratio increased, as well as that in arachidonic acid. Despite TGs major role to provide energy, their compositional modifications were linked to alterations in the physical properties of cellular membranes [45]. The main reason behind this is that they are incorporated into the lipid bilayer and assist the maintenance of cell membranes.…”