| Project/Area Number |
60470156
|
|---|
| Research Category |
Grant-in-Aid for General Scientific Research (B)
|
| Allocation Type | Single-year Grants |
|---|
| Research Field |
物質生物化学
|
|---|
| Research Institution | Faculty of Science, Osaka University |
|---|
Principal Investigator |
MATSUBARA Hiroshi Department of Biology, Faculty of Science, Osaka University, 理学部, 教授 (00028242)
|
|---|
| Co-Investigator(Kenkyū-buntansha) |
TSUKIHARA Tomitake Department of Engineering Chemistry, Faculty of Engineering, Tottori University, 工学部, 助教授 (00032277)
TAKAHASHI Yasuhiro Department of Biology, Faculty of Science, Osaka University, 理学部, 教務員 (10154874)
HASE Toshiharu Department of Biology, Faculty of Science, Osaka University, 理学部, 助手 (00127276)
|
|---|
| Project Period (FY) |
1985 – 1986
|
| Project Status |
Completed (Fiscal Year 1986)
|
| Budget Amount *help |
¥5,600,000 (Direct Cost: ¥5,600,000)
Fiscal Year 1986: ¥1,200,000 (Direct Cost: ¥1,200,000)
Fiscal Year 1985: ¥4,400,000 (Direct Cost: ¥4,400,000)
|
|---|
| Keywords | Cytochrome <C_1> / Hinge Proteins / Autoxidizability / Gene Engineering / Deletion at C-Terminal Region / Heme Ligands / FNR / Fe-Sフラスター形成 |
|---|
| Research Abstract |
The cytochrome <C_1> subcomplex of beef heart mitochondria was reacted with 3 molar equivalents of pCMB to modify 3 SH-groups. The two subunits (heme-subunit and hinge protein) were not separated on gel filtration, but by electrophoresis after this treatment, leading to the appearance of autoxidizability of <C_1> heme subunit. This indicates that the hinge protein is indispensable not only for complex formation between <C_1> and c, but also for obstructing the <C_1> heme subunit from autoxidation. The heme subunit seems to polymerize if the hinge protein is not associated.
Some mutated genes of cytochrome <C_1> were introduced into yeast cells to see how they affect the growth of yeast, respiratory ability, spectral characteristics, assembly into mitochondrial inner membrane, and gene expression. The deletion of 17 amino acids from the carboxyl-terminal region of <C_1> did not affect at all these characteristics, but when 70 amino acids from the carboxyl-terminal region were deleted, the protein modified lost the ability to be integrated into complex III of respiratory chain, and growth as well as respiration. This was partly predicted when the structure of beef cytochrome <C_1> was established. The work on this line is very promising to elucidate structure-function relationship of not only cytochrome <C_1> , but other membranous proteins. Other works done during this term are as follows: Identification of the heme iron ligands, crystallizations of <C_1> and ferredoxin <NADP^+> reductase, characterization of SH-groups in this enzyme, and iron-sulfur cluster formation.
|
