Figure 3.

Conformational changes of the Leu³³ and Pro³³ isoforms of α_IIbβ₃ during MD simulations. A, two-dimensional histogram of the RMSD of C^α atoms of the entire ectodomain after mass-weighted fitting on the β-propeller and βA domains of the starting structure versus R_g for the ectodomains. Bluish colors represent the three MD simulations of the Leu³³ isoform, and reddish colors represent those of the Pro³³ variant. B–D, histograms of the kink, bending, and splaying angles averaged over three MD simulations with error bars showing the S.E. and asterisks indicating the statistical significance (*, p < 0.05; ***, p < 0.0001). Above the plots, the definitions of the angles are given: B, kink angles as black solid line connecting the three points (center of mass of C^α atoms of Lys¹¹² and Ile¹¹⁸, center of mass of C^α atoms of Gln¹¹⁹ and Lys¹²⁵, and center of mass of C^α atoms of Leu¹²⁶ and Leu¹³²) on both isoforms; C, bending angle as a black solid line connecting the three points (center of mass of the β-propeller and βA domains, center of mass of the PSI domain, and center of mass of the calf-2 and β-tail domains); D, splaying angle as a black solid line connecting the three points (center of mass of C^α atoms of Leu⁷⁸⁸ and Gly⁷⁹⁶ in the calf-2 domain, center of mass of the C^α atoms of Cys⁶⁰² and Cys⁶⁰⁸ in the thigh domain, and center of mass of C^α atoms of Glu¹⁵⁵⁷ and Val¹⁵⁶¹ in the β-tail domain).