Single-molecule phospholipase A₂ becomes processive on melittin-induced membrane deformations

Area of Science:

• Biochemistry
• Membrane Biology
• Biophysics

Background:

• Lipid membrane topology influences biochemical processes.
• The synergistic mechanism of bee venom components melittin and phospholipase A2 (PLA2) in membrane disruption was not well understood.

Purpose of the Study:

• To investigate how melittin and PLA2 interact and remodel membranes.
• To elucidate the mechanism behind their synergistic activation and enhanced lytic effects.

Main Methods:

• Membrane reconstitution experiments were utilized.
• Single-molecule tracking of PLA2 was employed to observe its behavior on remodeled membranes.

Main Results:

• Melittin was found to induce large-scale membrane deformities.
• PLA2 activity was observed to be 25-fold higher on these melittin-induced membrane structures.
• Enhanced PLA2 activity was attributed to its processive behavior on the deformed membrane topology.

Conclusions:

• Melittin and PLA2 exhibit synergistic membrane-lysing effects through active membrane remodeling.
• Melittin creates topological structures that significantly enhance PLA2 activity.
• This study demonstrates how active alteration of membrane topology can modulate membrane-bound reactions.