Myoglobin-CO conformational substate dynamics: 2D vibrational echoes and MD simulations.
Two-dimensional (2D) infrared vibrational echoes were performed on horse heart carbonmonoxymyoglobin (MbCO) in water over a range of temperatures. The A(1) and A(3) conformational substates of MbCO are found to have different dephasing rates with different temperature dependences. A frequency-frequency correlation function derived from molecular dynamics simulations on MbCO at 298 K is used to calculate the vibrational echo decay. The calculated decay shows substantial agreement with the experimentally measured decays. The 2D vibrational echo probes protein dynamics and provides an observable that can be used to test structural assignments for the MbCO conformational substates.
Merchant
Kusai A
KA
Department of Chemistry, Stanford University, Stanford, California 94305, USA.
Thompson
David E
DE
Xu
Qing-Hua
QH
Williams
Ryan B
RB
Loring
Roger F
RF
Fayer
Michael D
MD
D000818:Animals; D055592:Biophysical Phenomena; D001703:Biophysics; D006736:Horses; D009211:Myoglobin / Q000737:chemistry*; D011487:Protein Conformation; D013055:Spectrophotometry, Infrared; D013816:Thermodynamics
D009211:Myoglobin; C018013:carboxymyoglobin