Conformational distribution of the oxidized (left) and reduced (right) αIIbβ3 integrin, obtained from MD simulations, starting from the bent apo (A) and extended holo (C) conformation. The MD trajectories are projected along two major conformational modes, obtained from principal component analysis. The color code shows the density of conformations, ranging from low (white) to high (dark blue) density (in arbitrary units). Disulfide reduction increases the covered area and, thus, the conformational fluctuations. Allosteric signaling network upon reduction of the Cys177-Cys184 disulfide bond in the bent apo (B) and extended holo (D) conformations, recovered from force distribution analysis. Only pairs of residues for which the pair-wise force difference was larger than a 55 pN cutoff value are shown. Differences in pairwise forces are shown as blue sticks, calcium and magnesium ions as yellow and orange spheres, the β propeller domain as a green cartoon and the βI domain as a cyan cartoon. The peptide ligand is not shown. Stress intensity is indicated by the color spectrum as used for b-factors (spectrum ranging from 55 pN - 268 pN force difference between the oxidized and reduced integrin headpiece in (B) and from 55 pN - 165 pN in (C).