Annexin V forms calcium-dependent trimeric units on phospholipid vesicles.
The quaternary structure of annexin V, a calcium-dependent phospholipid binding protein, was investigated by chemical cross-linking. Calcium was found to induce the formation of trimers, hexamers, and higher aggregates only when anionic phospholipids were present. Oligomerization occurred under the same conditions annexin-vesicle binding. A model is proposed in which cell stimulation leads to calcium-induced organization of arrays of annexin V lining the inner membrane surface, thus altering properties such as permeability and fluidity.
Concha
N O
NO
Department of Physiology, Boston University School of Medicine, MA 02118-2394.
Head
J F
JF
Kaetzel
M A
MA
Dedman
J R
JR
Seaton
B A
BA
D017304:Annexin A5 / Q000737:chemistry* / Q000187:drug effects; D002118:Calcium / Q000494:pharmacology*; D003432:Cross-Linking Reagents; D046911:Macromolecular Substances; D008567:Membranes, Artificial; D010743:Phospholipids; D011487:Protein Conformation / Q000187:drug effects*
D017304:Annexin A5; D003432:Cross-Linking Reagents; D046911:Macromolecular Substances; D008567:Membranes, Artificial; D010743:Phospholipids; D002118:Calcium