File:Structural-Basis-and-Kinetics-of-Force-Induced-Conformational-Changes-of-an-αA-Domain-Containing-pone.0027946.s008.ogv

English: SMD simulation of pulling the α7-helix of the LFA-1 αA domain. The simulated structures were shown in cyan with the α7-helix shown in green. The equilibrated α7-helix at the up (blue) and down (red) positions are superimposed for comparison. The Mg2+ ion is shown as golden spheres. A 250-pN force was applied to the Cα atom of the residue 308 at the C-terminal of the α7-helix. At 15 ns, the force was released to allow the system to relax. The Cα atoms of residues 131–135, 167–172, 177–181 and 232–234 of the β1–β4 strands were constrained to prevent the rigid body motion of the αA domain. The backbone hydrogen-bonding atoms in the α7-helix were constrained to prevent it from unfolding.