Spontaneous Quaternary and Tertiary T-R Transitions of Human Hemoglobin in Molecular Dynamics Simulation
(A–C) Projections of Hb structures during simulations R.HC3-1 to R.HC3-3 on the two eigenvectors derived from a PCA of the T, R, and R2 X-ray structures. The T, R, R2, RR2, and R3 X-ray structures are indicated by black dots. The color encodes the rotRMSD with respect to the T X-ray structure. (D) rotRMSD of simulations R.HC3-1 to R.HC3-3 with respect to the T X-ray structure. No R→T transition occurs within simulation time, but simulations R.HC3-1 and R.HC3-3 approach the RR2 structure on a sub-100-nanosecond timescale.