Structure of membrane‐bound human factor Va

FEBS Letters

Brisson, Alain²  Mann, Kenneth G.¹  Stoylova, Svetla² 

[1] Department of Biochemistry, University of Vermont, Burlington, VT 05405-0068, USA;Laboratoire de Génétique Moléculaire des Eucaryotes, CNRS, Unité 184 de Biologie Moléculaire et de Génie Gén'etique, INSERM, Institut de Chimie Biologique, Faculté de Médecine, 11 rue Humann, 67085 Strasbourg Cedex, France

关键词: Factor Va;    Two-dimensional crystal;    Electron microscopy;    Phosphatidylserine;    Liposome;    2D;    two-dimensional;    3D;    three-dimensional;    EDTA;    ethylenediaminetetraacetic acid;    EM;    electron microscopy;    PC;    dioleoylphosphatidylcholine;    PS;    dioleoylphosphatidylserine;    UA;    uranyl acetate;   

DOI  :  10.1016/0014-5793(94)00881-7

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Coagulation factor Va is an essential cofactor which combines with the serine protease factor Xa on a phospholipid surface to form the prothrombinase complex. In the present study, the structure of factor Va interacting with lipid surfaces containing phosphatidylserine was studied by electron microscopy. Two-dimensional crystals of factor Va were obtained on planar lipid films under quasi-physiological conditions. The two-dimensional projected structure of factor Va was calculated at a resolution of 2 nm, revealing dimers of factor Va arranged on the surface lattice with the symmetry of the plane group p2. Average unit cell dimensions are a = 14.4 nm, b = 8.8 nm, γ = 107°. Each factor Va molecule presents two distinct domains of protein density consisting of one small domain, of 3 nm in diameter, connected to a larger domain of about 6 nm × 4.5 nm. The projected structure of factor Va covers an area equivalent to about fifty phospholipid molecules. In addition, edge-on views of factor Va molecules bound to liposomes reveal a globular structure connected through a thin stem to the liposome surface. A three-dimensional model of membrane-bound factor Va is proposed.

【 授权许可】

Unknown