| Project/Area Number |
06660423
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
Applied molecular and cellular biology
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| Research Institution | Tokyo University of Agriculture |
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Principal Investigator |
UDAKA Shigezo Tokyo University of Agriculture, Department of Brewing & Fermentation, Professor, 農学部, 教授 (70023463)
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| Project Period (FY) |
1994 – 1995
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| Project Status |
Completed (Fiscal Year 1995)
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| Budget Amount *help |
¥2,100,000 (Direct Cost: ¥2,100,000)
Fiscal Year 1995: ¥800,000 (Direct Cost: ¥800,000)
Fiscal Year 1994: ¥1,300,000 (Direct Cost: ¥1,300,000)
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| Keywords | Bacillus brevis / Disulfide bond of protein / Protein folding / Protein secretion |
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| Research Abstract |
We have shown that human proteins having several disulfide bonds in their molecules can be efficiently secreted by the Bacillus brevis host-vector system which we developed. In this system, a disulfide bond forming enzyme must have an important role in the formation of the correctly folded and biologically active protein after the translocation across the membrane of the unfolded polypeptide. So we cloned the gene (bdb) for protein thiol-disulfide exidoreductase (a disulfide bond forming enzyme) from Bacillus brevis that encodes a protein consisting of 117 amino acids with a signal peptide of 27 residues. Bdb contains a well-conserved motif, Cys-X-X-Cys, which functions as the active center of proteins such as protein disulfide isomerase and thioredoxin. The bdb gene complemented the Escherichia coli dsbA mutation, restoring motility by means of flagellar and alkaline phosphatase activity. The Bdb protein overproduced in B.brevis was enzymatically active in both reduction and oxidation of disulfide bonds in vitro. Immunoblotting indicated that Bdb could function at the periphery of the cell.
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