Calcium-dependent and -independent annexin V binding: distinct molecular behaviours at cell membrane interfaces.

Distinct annexin V binding behaviours in Ca2+-dependent and Ca2+-independent cases were comparatively investigated using sum frequency generation vibrational spectroscopy. It was discovered that binding affected the molecular arrangement of both membrane leaflets, and the initial Ca2+-independent binding went through a transition with annexin V reorientation to a more stable state upon adding Ca2+.