The calcium-dependent binding of annexin V to phospholipid vesicles influences the bilayer inner fluidity gradient

Research was conducted to demonstrate that the calcium-dependent binding of annexin V to phospholipid vesicles influences the bilayer inner fluidity gradient. Phospholipids spin labeled at positions C-5, C-12 and C-16 were used to study the response of the phospholipids involved in the interaction. Results indicate that membrane rigidification seemed to parallel the crystallizing tendency of vesicle-bound annexin V but may not be involved in the calcium channeling activity of the protein.