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 ≈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.
| Original language | English |
|---|---|
| Pages (from-to) | 8619-8624 |
| Number of pages | 6 |
| Journal | Proceedings of the National Academy of Sciences of the United States of America |
| Volume | 105 |
| Issue number | 25 |
| DOIs | |
| Publication status | Published - 2008 Jun 24 |
| Externally published | Yes |
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Keywords
- Multidimensional IR spectroscopy
- Myoglobin
- Protein dynamics
- Protein structural change
- Ultrafast IR
ASJC Scopus subject areas
- General
Cite this
Direct observation of fast protein conformational switching. / Ishikawa, Haruto; Kwak, Kyungwon; Chung, Jean K.; Kim, Seongheun; Fayer, Michael D.
In: Proceedings of the National Academy of Sciences of the United States of America, Vol. 105, No. 25, 24.06.2008, p. 8619-8624.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Direct observation of fast protein conformational switching
AU - Ishikawa, Haruto
AU - Kwak, Kyungwon
AU - Chung, Jean K.
AU - Kim, Seongheun
AU - Fayer, Michael D.
PY - 2008/6/24
Y1 - 2008/6/24
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 ≈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.
AB - 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 ≈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.
KW - Multidimensional IR spectroscopy
KW - Myoglobin
KW - Protein dynamics
KW - Protein structural change
KW - Ultrafast IR
UR - http://www.scopus.com/inward/record.url?scp=47249108055&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=47249108055&partnerID=8YFLogxK
U2 - 10.1073/pnas.0803764105
DO - 10.1073/pnas.0803764105
M3 - Article
VL - 105
SP - 8619
EP - 8624
JO - Proceedings of the National Academy of Sciences of the United States of America
JF - Proceedings of the National Academy of Sciences of the United States of America
SN - 0027-8424
IS - 25
ER -