RRC ID |
41487
|
著者 |
Matsunaga Y, Saito N, Fujii A, Yokotani J, Takakura T, Nishimura T, Esaki H, Yamada T.
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タイトル |
A pH-dependent conformational transition of Abeta peptide and physicochemical properties of the conformers in the glial cell.
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ジャーナル |
Biochem J
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Abstract |
In the present study we identified the epitopes of antibodies against amyloid beta-(1-42)-peptide (Abeta1-42): 4G8 reacted with peptides corresponding to residues 17-21, 6F/3D reacted with peptides corresponding to residues 9-14, and anti 5-10 reacted with peptides corresponding to residues 5-10. The study also yielded some insight into the Abeta1-42 structures resulting from differences in pH. An ELISA study using monoclonal antibodies showed that pH-dependent conformational changes occur in the 6F/3D and 4G8 epitopes modified at pH 4.6, but not in the sequences recognized by anti 1-7 and anti 5-10. This was unique to Abeta1-40 and Abeta1-42 and did not occur with Abeta1-16 or Abeta17-42. The reactivity profile of 4G8 was not affected by blockage of histidine residues of pH-modified Abeta1-40 and Abeta1-42 with diethyl pyrocarbonate; however, the mutant [Gln(11)]Abeta1-40 abrogated the unique pH-dependence towards 4G8 observed with Abeta1-40. These findings suggest that these epitopes are cryptic at pH 4.6, and that Glu(11) is responsible for the changes. We suggest that the abnormal folding of 6F/3D epitope affected by pH masked the 4G8 epitope. A study of the binding of metal ions to Abeta1-42 suggested that Cu(2+) and Zn(2+) induced a conformational transition around the 6F/3D region at pH 7.4, but did not affect the region when it was modified at pH 4.6. However, Fe(2+) had no effect, irrespective of pH. Abeta modified at pH 4.6 appeared to be relatively resistant to proteinase K compared with Abetas modified at pH 7.4, and the former might be preferentially internalized and accumulated in a human glial cell. Our findings suggest the importance of microenvironmental changes, such as pH, in the early stage of formation of Abeta aggregates in the glial cell.
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巻・号 |
361(Pt 3)
|
ページ |
547-56
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公開日 |
2002-2-1
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DOI |
10.1042/0264-6021:3610547
|
PMID |
11802784
|
PMC |
PMC1222337
|
MeSH |
Alzheimer Disease / metabolism
Amino Acid Sequence
Amino Acids / chemistry
Amyloid beta-Peptides / chemistry*
Antibodies, Monoclonal / metabolism
Blotting, Western
Cell Line
Densitometry
Enzyme-Linked Immunosorbent Assay
Epitope Mapping
Epitopes
Histidine / chemistry
Humans
Hydrogen-Ion Concentration
Iron / chemistry
Molecular Sequence Data
Neuroglia / cytology*
Peptide Biosynthesis
Protein Binding
Protein Conformation
Protein Structure, Tertiary
Sequence Homology, Amino Acid
Time Factors
|
IF |
4.097
|
引用数 |
17
|
WOS 分野
|
BIOCHEMISTRY & MOLECULAR BIOLOGY
|
リソース情報 |
ヒト・動物細胞 |
|