Direct observation of fast protein conformational switching

Haruto Ishikawa, Kyungwon Kwak, Jean K. Chung, Seongheun Kim, Michael D. Fayer

Research output: Contribution to journalArticle

98 Citations (Scopus)

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 languageEnglish
Pages (from-to)8619-8624
Number of pages6
JournalProceedings of the National Academy of Sciences of the United States of America
Volume105
Issue number25
DOIs
Publication statusPublished - 2008 Jun 24
Externally publishedYes

Fingerprint

Observation
Carbon Monoxide
Histidine
Proteins
Myoglobin
Heme
Catalytic Domain
Spectrum Analysis
Growth

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 journalArticle

Ishikawa, Haruto ; Kwak, Kyungwon ; Chung, Jean K. ; Kim, Seongheun ; Fayer, Michael D. / Direct observation of fast protein conformational switching. In: Proceedings of the National Academy of Sciences of the United States of America. 2008 ; Vol. 105, No. 25. pp. 8619-8624.
@article{11f94ec12d7e4aee9b89a6b36bb437cd,
title = "Direct observation of fast protein conformational switching",
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.",
keywords = "Multidimensional IR spectroscopy, Myoglobin, Protein dynamics, Protein structural change, Ultrafast IR",
author = "Haruto Ishikawa and Kyungwon Kwak and Chung, {Jean K.} and Seongheun Kim and Fayer, {Michael D.}",
year = "2008",
month = "6",
day = "24",
doi = "10.1073/pnas.0803764105",
language = "English",
volume = "105",
pages = "8619--8624",
journal = "Proceedings of the National Academy of Sciences of the United States of America",
issn = "0027-8424",
number = "25",

}

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 -