Direct observation of fast protein conformational switching

@article{citeulike:2924998, abstract = {Folded proteins can exist in multiple conformational substates. Each substate reflects a local minimum on the free-energy landscape with a distinct structure. By using ultrafast 2D-IR vibrational echo chemical-exchange spectroscopy, conformational switching between two well defined substates of a myoglobin mutant is observed on the {approx}50-ps time scale. The conformational dynamics are directly measured through the growth of cross peaks in the 2D-IR spectra of CO bound to the heme active site. The conformational switching involves motion of the distal histidine/E helix that changes the location of the imidazole side group of the histidine. The exchange between substates changes the frequency of the CO, which is detected by the time dependence of the 2D-IR vibrational echo spectrum. These results demonstrate that interconversion between protein conformational substates can occur on very fast time scales. The implications for larger structural changes that occur on much longer time scales are discussed. 10.1073/pnas.0803764105}, author = {Ishikawa, Haruto and Kwak, Kyungwon and Chung, Jean K. and Kim, Seongheun and Fayer, Michael D. }, citeulike-article-id = {2924998}, doi = {10.1073/pnas.0803764105}, journal = {Proceedings of the National Academy of Sciences}, keywords = {protein, structure}, month = {June}, number = {25}, pages = {8619--8624}, posted-at = {2008-06-25 05:44:14}, priority = {2}, title = {Direct observation of fast protein conformational switching}, url = {http://dx.doi.org/10.1073/pnas.0803764105}, volume = {105}, year = {2008} }

TY - JOUR ID - citeulike:2924998 L3 - citeulike-article-id:2924998 TI - Direct observation of fast protein conformational switching JF - Proceedings of the National Academy of Sciences VL - 105 IS - 25 SP - 8619 EP - 8624 N2 - Folded proteins can exist in multiple conformational substates. Each substate reflects a local minimum on the free-energy landscape with a distinct structure. By using ultrafast 2D-IR vibrational echo chemical-exchange spectroscopy, conformational switching between two well defined substates of a myoglobin mutant is observed on the {approx}50-ps time scale. The conformational dynamics are directly measured through the growth of cross peaks in the 2D-IR spectra of CO bound to the heme active site. The conformational switching involves motion of the distal histidine/E helix that changes the location of the imidazole side group of the histidine. The exchange between substates changes the frequency of the CO, which is detected by the time dependence of the 2D-IR vibrational echo spectrum. These results demonstrate that interconversion between protein conformational substates can occur on very fast time scales. The implications for larger structural changes that occur on much longer time scales are discussed. 10.1073/pnas.0803764105 KW - protein KW - structure AU - Ishikawa, Haruto AU - Kwak, Kyungwon AU - Chung, Jean AU - Kim, Seongheun AU - Fayer, Michael PY - 2008/06/24/ UR - http://dx.doi.org/10.1073/pnas.0803764105 ER -