1 research outputs found
Phospholipase A<sub>2</sub>‑Induced Remodeling Processes on Liquid-Ordered/Liquid-Disordered Membranes Containing Docosahexaenoic or Oleic Acid: A Comparison Study
Vesicle cycling, which is an important
biological event, involves
the interplay between membrane lipids and proteins, among which the
enzyme phospholipase A<sub>2</sub> (PLA<sub>2</sub>) plays a critical
role. The capacity of PLA<sub>2</sub> to trigger the budding and fission
of liquid-ordered (L<sub>o</sub>) domains has been examined in palmitoyl-docosahexaenoylphosphatidylcholine
(PDPC) and palmitoyl-oleoylphosphatidylcholine (POPC)/sphingomyelin/cholesterol
membranes. They both exhibited a L<sub>o</sub>/liquid-disordered (L<sub>d</sub>) phase separation. We demonstrated that PLA<sub>2</sub> was
able to trigger budding in PDPC-containing vesicles but not POPC ones.
The enzymatic activity, line tension, and elasticity of the membrane
surrounding the L<sub>o</sub> domains are critical for budding. The
higher line tension of L<sub>o</sub> domains in PDPC mixtures was
assigned to the greater difference in order parameters of the coexisting
phases. The higher amount of lysophosphatidylcholine generated by
PLA<sub>2</sub> in the PDPC-containing mixtures led to a less-rigid
membrane, compared to POPC. The more elastic L<sub>d</sub> membranes
in PDPC mixtures exert a lower counteracting force against the L<sub>o</sub> domain bending