The Characterization of Weak Protein–Protein Interactions: Evidence from DEER for the Trimerization of a von Willebrand Factor A Domain in Solution

Abstract

Distance determination: A double electron electron resonance (DEER) measurement of a distance of 6.1 nm (green lines) between singly nitroxide-labeled human von Willebrand Factor A domains demonstrates oligomerization of this domain in dilute solution (see structure); probably in an arrangement similar to that observed in the crystal structure. The DEER technique should be generally applicable for characterizing noncovalent interactions between macromolecules in solution.