Activation mechanism of prokallikrein and its hormonal regulation in the kidney
| Project/Area Number |
62571002
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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 |
Biological pharmacy
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| Research Institution | Osaka University of Pharmaceutical Sciences |
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Principal Investigator |
MORIMOTO Shiro Dept. of Pharmacol., Osaka Univ. of Pharmaceutical Sciences, 薬理学教室, 教授 (60067270)
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| Co-Investigator(Kenkyū-buntansha) |
MATSUMURA Yasuo Dept. of Pharmacol., Osaka Univ. of Pharmaceutical Sciences, 薬理学教室, 助手 (40140230)
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| Project Period (FY) |
1987 – 1988
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| Project Status |
Completed (Fiscal Year 1988)
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| Budget Amount *help |
¥2,100,000 (Direct Cost: ¥2,100,000)
Fiscal Year 1988: ¥400,000 (Direct Cost: ¥400,000)
Fiscal Year 1987: ¥1,700,000 (Direct Cost: ¥1,700,000)
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| Keywords | Rat kidney / Kallikrein / Prokallikrein / Propeptide / Activator / Thio proteinase / 糖質コルチコイド / アミノ酸配列 / アルドステロン / デキサメサゾン |
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| Research Abstract |
1. Antibody was raised against a synthetic peptide corresponding to the predicted prosegment (Arg-Asn-Asp-Ala-Pro-Pro-Val-Gln-Ser-Arg) of rat tissue kallikrein precursor, and an enzyme immunoassay method for the peptide was developed. Using this method, we obtained evidence that rat urinary inactive kallikrein is indeed a proform of tissue kallikrein.
2. Apeptide released from rat urinary prokallikrein by trypsin treatment comprised 7 amino acids, the sequence (Ala-Pro-Pro-Val-Gln-Ser-Arg) of which was identical with that of n-terminal region of the prokallikrein. These results indicate that rat urinaryprokallikrein is converted to the active form with the release of N-terminal propeptide consisting 7 amino acids by limited proteolysis with trypsin.
3. A prokallikrein-activating proteinase was purified to apparent homogeneity from the rat kidney cortex. The resulting preparation, termed activator I, was a thiol proteinase with a molecular weight of 57,000. The data obtained in the immunodiffision experiments indicate that activator I is probably present in the submandibular gland, a tissue known to contain high levels of tissue kallikrein enzyme and its mRNA.
4. An assay method was developed to measure quantitatively the proteinase responsible for activation of prokallikrein in the rat kidney. The renal proteinase was evaluated by incubating the purified rat urinary prokallikrein with the renal cortical extract in the presence of cysteine pH 5.0. Levels of the renal proteinase responsible for activation of prokallikrein remained unchanged with an increase in endogenous aldosterone by low sodium intake. On the other hand, administration of dexamethasone caused a significant decrease in the proteinase activity. These results suggest that the activation process of prokallikrein is regulated by glucocorticoids, in the rat kidney.
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Report
(3 results)
Research Products
(13 results)
