Determination of the solution structure of a platelet-adhesion peptide of von Willebrand factor.

Two-dimensional nuclear magnetic resonance (NMR) spectroscopy in combination with distance geometry (DG) and dynamical simulated annealing (DSA) calculations have been used to determine the tertiary solution structure of a synthetic 29-residue fragment of von Willebrand factor (vWF). This fragment (D514-E542) represents an adhesion site on vWF for its platelet receptor, the glycoprotein Ib-IX complex (GP Ib-IX). The NMR data yielded 109 interproton distance measurements and two chi 1 dihedral angle constraints for use in DG and DSA calculations. Most prominent in the calculated family of solution structures was an amphipathic, right-handed alpha-helix in the C-terminal segment of the peptide. We propose that this highly structured region may be important for the specific molecular interaction of vWF with the GP Ib-IX complex.