Summary
Protein conformational variability (or dynamics) for large macromolecules and its
implication for their biological function attracts more and more attention. Collective
motions of domains increase the ability of a protein to bind to partner molecules.
Using atomic force microscopy (AFM) topographic images, it is possible to take snapshots
of large multi-component macromolecules at the single molecule level and to reconstruct
complete molecular conformations. Here, we report the application of a reconstruction
protocol, named AFM-assembly, to characterise the conformational variability of the
two C domains of human coagulation factor Va (FVa). Using AFM topographic surfaces
obtained in liquid environment, it is shown that the angle between C1 and C2 domains
of FVa can vary between 40° and 166°. Such dynamical variation in C1 and C2 domain
arrangement may have important implications regarding the binding of FVa to phospholipid
membranes.
Keywords
Coagulation factors - imaging - phospholipids - protein structure / folding - atomic
force microscopy