1998 Fiscal Year Final Research Report Summary
Role of Complement C5a/C3a agonists existing broadly in animals and plants
| Project/Area Number |
09660084
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
応用微生物学・応用生物化学
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| Research Institution | KYOTO UNIVERSITY |
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Principal Investigator |
YOSHIKAWA Masaaki Kyoto University, Research Institute for Food Science, Professor, 食糧科学研究所, 教授 (50026572)
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| Co-Investigator(Kenkyū-buntansha) |
TAKENAKA Yasuyuki Kyoto University, Research Institute for Food Science, Instructor, 食糧科学研究所, 助手 (20273518)
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| Project Period (FY) |
1997 – 1998
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| Keywords | complement / C3a / C5a / peptide / food protein / casein / albumin / albutensin |
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| Research Abstract |
Complement C3a which is released from the amino-terminus region of Complement C3 induces inflammation and contraction of smooth muscle. We found that Complement C3a shows central effects such as anti-analgesia and anti-amnesia. Low molecular weight C3a agonists we isolated from tryptic digests of casein, rice albumin, hemoglobin, serum albumin and histone have common sequence at their carboxyl termini, hydrophobic residue-X_1-Leu-X_2-Arg. These peptides might bind C3a receptor because the sequence is common to that at the carboxyl terminus of C3a. Similar peptides were found in the primary structure of some endogenous bioactive peptides. Only a part of such peptides might have' physiological significance because such peptides are found broadly not only in animals but also in plants.
Complement C5a which is also released from the amino-terminus region of Complement C5 has potent biological activities common to those of C3a. Albutensin A, Ala-Phe-Lys-Ala-Trp-Ser-Leu-Ala-Arg, which is released from porcine serum albumin binds both C3a and C5a receptors. On the other hand, Phe-Lys-Asp-Cys-His-Leu-Ala-Arg, which is released from lactoferrin binds C5a receptor. The Lys at the 7th residue from the carboxyl terminus seems to be essential for C5a receptor affinity since the structure at the carboxyl terminus of C5a is Lys-Asp-Met-Gln-Leu-Gly-Arg. Thus, C3a and C5a agonists existing broadly in animal and plants. It is expected to use some of them as pharmaceutical drugs or foods to improve our health.
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