The calcium binding sites in human annexin V by crystal structure analysis at 2.0 A resolution Implications for membrane binding and calcium channel activity

FEBS Letters

Paques, Eric-P.²  Mayr, Irmgard¹  Huber, Robert¹  Römisch, Jürgen²  Schneider, Monika¹ 

[1] Max Planck Institut für Biochemie D-8033 Martinsried, FRG;Forschungslaboratorien der Behringwerke, D-3550 Marburg Lahn, FRG

关键词: Annexin;    Crystal structure;    Calcium;    Membrane;    Channel;   

DOI  :  10.1016/0014-5793(90)81428-Q

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Crystal structure analysis and refinement at 2.0 A resolution of a rhombohedral crystal form of human annexin V at high calcium concentration revealed a domain motion compared to the previously analysed hexagonal crystal form. Five calcium ions were located on the convex face of the molecule. Three strongly bound calciums are liganded at protruding interhelical loops and Asp or Glu residues in homologous positions in repeats I, II and IV. Five proteinaceous oxygens and one solvent molecule form the coordination polyhedron in each case. The unoccupied seventh site is suggested as the phospholipid headgroup binding site. Two more weakly bound sites were identified by lanthanum labelling. The structural features suggest that annexin V attaches with its convex face to membranes by specified calcium mediated interactions with at least three phospholipids. The adjacent membrane bilayer may thus become locally disordered and permeable to allow calcium inflow through the central polar channel of the molecule.

【 授权许可】

Unknown