| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
|
|
|
|||||||
|
|||||||||
J. Biol. Chem., Vol. 281, Issue 34, 24637-24646, August 25, 2006
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
1
From the
School of Advanced Sciences, the Graduate University for Advanced Studies, Hayama, Kanagawa 240-0193, the Okazaki Institute for Integrative Bioscience, National Institutes of Natural Sciences, Okazaki, Aichi 444-8787, and the ||Graduate School of Engineering, Osaka University, Suita, Osaka 565-0871, Japan
Gas sensory heme proteins respond to their environment by binding a specific gas molecule to heme and transmitting this primary binding signal to the protein. How the binding signal is transmitted from the heme to the protein remains to be clarified. Using UV resonance Raman (UVRR) spectroscopy, we investigated this pathway in sperm whale myoglobin as a model gas sensory heme protein. Based on the UVRR data and the effects of deleting one of three important pathways (His-93, 6-propionate, or 7-propionate), we determined the changes in the conformation of globin that occur upon binding of CO, nitric oxide (NO), or O2 to heme and how they are transmitted from heme to globin. The UVRR results show that heme discriminates different ligands, resulting in different conformations in the globin protein. Specifically, NO induces changes in the spectrum of Trp residues in the A-helix that are significantly different from those induced by O2 or CO binding. On the other hand, binding of O2 to heme produces changes in the Tyr residues of the H-helix that are different from those induced by CO or NO binding. Furthermore, we found that cleavage of the Fe-His-93 covalent bond eliminates communication to the terminal region of the H-helix and that the 7-propionate hydrogen-bonding network is essential for transmitting the CO or NO binding signal to the N and C termini. Finally, the 6-propionate is important only for NO binding. Thus, the hydrogen-bonding network in the protein appears to be critical for intramolecular signal transduction in gas sensory heme proteins.
Received for publication, April 4, 2006 , and in revised form, June 9, 2006.
* This study was supported by Grant-in-aid 14001004 for specially promoted research from the Ministry of Education, Culture, Sports, Science, and Technology of Japan (to T. K.) and by a JSPS Fellowship from the Japan Society for the Promotion of Science (to S. F. E.-M.). The costs of publication of this article were defrayed in part by the payment of page charges. This article must therefore be hereby marked "advertisement" in accordance with 18 U.S.C. Section 1734 solely to indicate this fact.
The on-line version of this article (available at http://www.jbc.org) contains a supplemental figure.
1 To whom correspondence should be addressed. Tel.: 81-564-59-5225; Fax: 81-564-59-5229; E-mail: teizo{at}ims.ac.jp.
This article has been cited by other articles:
|
|
 |
|
  S. F. El-Mashtoly, Y. Gu, H. Yoshimura, S. Yoshioka, S. Aono, and T. Kitagawa Protein Conformation Changes of HemAT-Bs upon Ligand Binding Probed by Ultraviolet Resonance Raman Spectroscopy J. Biol. Chem., March 14, 2008; 283(11): 6942 - 6949. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 A. Sato, Y. Gao, T. Kitagawa, and Y. Mizutani Primary protein response after ligand photodissociation in carbonmonoxy myoglobin PNAS, June 5, 2007; 104(23): 9627 - 9632. [Abstract] [Full Text] [PDF]
|
|
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| All ASBMB Journals | Molecular and Cellular Proteomics |
| Journal of Lipid Research | ASBMB Today |
