2004 Fiscal Year Final Research Report Summary
Characterization of D-amino acid containing protein from sun-damaged skin of elderly donors.
| Project/Area Number |
14390032
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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 |
広領域
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| Research Institution | KYOTO UNIVERSITY |
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Principal Investigator |
FUJII Noriko Kyoto University, Research Reactor Institute, Professor, 原子炉実験所, 教授 (90199290)
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| Co-Investigator(Kenkyū-buntansha) |
TAJIMA Shingo National Defense Medical College, Professor, 教授 (60129525)
SHIMO-OKA Tadashi Asahi Techno Glass Corp, Life Science Center, Director, ライフサイエンスセンター長
SAITO Takeshi Kyoto University, Research Reactor Institute, Lecturer, 原子炉実験所, 助手 (10274143)
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| Project Period (FY) |
2002 – 2004
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| Keywords | Aging / UV irradiation / sun-damage / D-amino acid / Racemization / Isomerization / skin / Posttranslational modification |
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| Research Abstract |
1)Biologically uncommon D-beta-aspartic acid-containing protein in elastic fibers of sun damaged skin.
We have prepared the antibody against D-beta-Asp containing protein and examined its immunoreactivity in skin. The antibody recognized disintegrated elastic fibers in sun-exposed skin. Western plot analysis of the proteins isolated from sun-damaged skin demonstrated that the polypeptide with 50kDa was immunoreactive with the antibodies for D-beta-Asp containing protein and elastin. This result suggests that UV irradiation siginificant racemization and isomerization of Asp resideus in proteins of elastic fibers and the unusual proteins were accumulated during aging. Subsequnetly, we identified some D-beta-Asp containing proteins by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry and the Mascot online database searching algorithm.
We propose that the antibody could be a useful indicator for sun damage of the skin.
2) Kinetic Study of racemization of aspartyl residues in model peptides corresponding to sections of elastin
We synthesized three Asp-containing model peptides corresponding to sections of elastin:1) GVADAAAA, 2) REGDPSSS, 3) AGADEGVR. We calculated the activation energy of the racemization of Asp residues in the three peptide and the time required for the Asp D/L ratio to approximate to 1.0 at body temperature(37℃). The racemization of Asp in the peptides progressed on the basis of the first order reaction. The Asp residue in the peptide No2 is the most susceptible to racemization, while the Asp residue in the peptide No1 is the least susceptible. However, there was little difference the racemization rate of Asp among three peptides. At 37℃, the time required for the D/L ratios of Asp in these peptides to 0.999 was calculated to be 50-100 years. These results suggested that the racemization of Asp occurred in skin of elderly humans.
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