2006 Fiscal Year Final Research Report Summary
Studies on the mechanism of amyloid fibril formation using yeast expression system of amyloidogenic proteins and the search of food components to prevent the formation of amyloid fibril
| Project/Area Number |
17380080
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Food science
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| Research Institution | Yamaguchi University |
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Principal Investigator |
KATO Akio Yamaguchi University, Professor Emeritus, 名誉教授 (00035114)
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| Co-Investigator(Kenkyū-buntansha) |
AZAKAMI Hiroyuki Yamaguchi University, Faculty of Agriculture, Associate Professor, 農学部, 助教授 (40263850)
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| Project Period (FY) |
2005 – 2006
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| Keywords | amyloidosis / amyloidogenic lysozyme / amyloidogenic cystatin / Pichia pastoris expression / PQQ / catechin / エピガロカテキン |
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| Research Abstract |
We are successful to secrete amyloidogenic proteins such as mutant lysozyme and cystatin in yeast expression system. Therefore, it is easy to search the effective food components to prevent amyloid fibril formation of these amyloidogenic proteins. Thus, we found that catechin, epigarocatechin and PQQ (pyrroloquinoline quinine) are efficiently prevent the amyloid fibril formation using yeast expression system of amyloidogenic cystatin. In addition, the yeast secretion system of amyloidogenic proteins enabled to address how to prevent amyloidosis using various mutants of amyloidogenic proteins such as lysozyme and cystatin. To address the role of glycosylation on the fibrillogenecity of cystatin, the consensus sequence for N-linked glycosylation was introduced by site-directed mutagenesis into the amyloidogenic cystatin. The glycosylation of amyroidogenic cystatin inhibited the formation of cystain dimmer. This finding suggests that the mechanism causing the prevention of amyloidogenic fibril formation may be the suppression of three-dimensional domain-swapped dimmers and oligomers. In addition, attempt to elucidate the mechanism of the amyloid fibril formation was carried out using various mutant amyloidogenic lysozymes. The helix-stabilizing mutant lysozyme suppressed the amyloidogenic fibril formation and increase inβ-structure. This suggests that a-helix of lysozyme converts into β-structure during amyloidosis of lysozyme.
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