| Project/Area Number |
01570235
|
|---|
| Research Category |
Grant-in-Aid for General Scientific Research (C)
|
| Allocation Type | Single-year Grants |
|---|
| Research Field |
細菌学
|
|---|
| Research Institution | Fujuta Health University |
|---|
Principal Investigator |
TSUJI Takao Fujita Health University, Department of Medicine, Assistant Professor, 医学部, 講師 (60171998)
|
|---|
| Project Period (FY) |
1989 – 1990
|
| Project Status |
Completed (Fiscal Year 1990)
|
| Budget Amount *help |
¥2,000,000 (Direct Cost: ¥2,000,000)
Fiscal Year 1990: ¥1,000,000 (Direct Cost: ¥1,000,000)
Fiscal Year 1989: ¥1,000,000 (Direct Cost: ¥1,000,000)
|
|---|
| Keywords | mutant / heat-labile enterotoxin / enterotoxigenic E coli / plasmid / ileal loop test / コレラ毒素 / A,Bサブユニット / アデニレ-トサイクラ-ゼ / 突然変異株 |
|---|
| Research Abstract |
A plasmid encoding a mutant gene of heat-labile enterotoxin (LT), produced by enterotoxigenic Escherichia coli, - was induced by treatment of plasmid EWD 299 with hydroxylamine. A mutant strain of E. coli HB 101 carrying the mutant plasmid pTUH 6A produced a low toxic LT analogue (mutant LT), which was cross-reactive with anti-LT antibody. The mutant LT activity was less than 0.15 and 0.006% of the normal LT in the rabbit ileal loop test and in the rabbit skin peameability test, respectively. The amino acid composition of the mutant LT-B subunit was the same as that of the normal B subunit. Though the A_2 fragment of the mutant LT was identical to normal LT by DNA analysis, the A_1 fragment of the mutant LT differed from the normal A_1 fragment in one amino acid at position 112 ; namely it had lysine instead of glutamic acid from the N terminus.
These data suggest that glutamic acid at position 112 from the N terminus of the A_1 fragment is important for the A subunit to express its biological activity.
|
