| Project/Area Number |
63540535
|
|---|
| Research Category |
Grant-in-Aid for General Scientific Research (C)
|
| Allocation Type | Single-year Grants |
|---|
| Research Field |
植物生理学
|
|---|
| Research Institution | Kumamoto University |
|---|
Principal Investigator |
MASAMOTO K. Kumamoto Univ., Fac. Education, Assoc. Prof., 教育学部, 助教授 (60136702)
|
|---|
| Project Period (FY) |
1988 – 1989
|
| Project Status |
Completed (Fiscal Year 1989)
|
| Budget Amount *help |
¥1,200,000 (Direct Cost: ¥1,200,000)
Fiscal Year 1989: ¥500,000 (Direct Cost: ¥500,000)
Fiscal Year 1988: ¥700,000 (Direct Cost: ¥700,000)
|
|---|
| Keywords | Carotenoprotein / Gene of Carotenoprotein / Carotenoid / Zeaxanthin / Cyanobacterium / Synechococcus sp. Pcc 7942 / 強光下培養 / Anacystis nidulans R2 |
|---|
| Research Abstract |
Studies on carotenoids of the cyanobacterium Synechococcus sp. PCC 7942 were summarized as follows.
1. The 42kD carotenoprotein was localized in the cytoplasmic membrane by immunochemical detection using isolated membranes as well as by electron microscopic immunocytochemistry.
2. The gene (cbpA) was cloned from a lambda EMBL3 library and sequenced, encoding 450 amino acids (49,113 daltons). The hydrophobicity plot suggests a 49-residue signal sequence which is cleaved to yield a mature protein of 43,709 daltons. Transcription is greatly induced by growth under high light intensities and repressed under iron-deficient conditions. Novobiocin inhibited the light-induced transcription. Since cbpA appears to be a component of the 6.2 Kb transcript, it is likely part of a larger operon.
3. Carotenoids of the cyanobacterium were identified by reversed-phase HPLC. Zeaxanthin was the major carotenoid in the cells grown under high light intensities; in those cells, carotenoid/chlorophyll ratio increased. The heavy membrane fraction (enriched with cell walls) from those cells contained 85% zeaxanthin and had an absorption peak at 380 nm, which suggests the aggregated form of zeaxanthin.
|
