1999 Fiscal Year Final Research Report Summary
Analysis of function of phosphopeptides from milk and egg phosphoproteins
| Project/Area Number |
09660289
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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 |
Zootechnical science/Grassland science
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| Research Institution | Kagoshima University |
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Principal Investigator |
AOKI Takayoshi Kagoshima University, Faculty of Agriculture, Professor, 農学部, 教授 (70034460)
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| Co-Investigator(Kenkyū-buntansha) |
IBRAHIM Hisham r. Kagoshima University, Faculty of Agriculture, Assistant Professor, 農学部, 講師 (90274836)
HAYASHI Kunioki Kagoshima University, Faculty of Agriculture, Professor, 農学部, 教授 (80041656)
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| Project Period (FY) |
1997 – 1999
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| Keywords | phosphopeptide / casein / riboflavin-binding protein / calcium / calcium phosphate / カゼインミセル |
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| Research Abstract |
Phosphopeptides were separated from the tryptic hydrolyzates of bovine αィイD2s1ィエD2-casein, bovine β-casein and egg white riboflavin-binding protein (RfBP). The inhibitory activity for calcium phosphate of these phosphopeptides was in the order of β-casein-4P (f1-25) > αィイD2s1ィエD2-casein-5P (f59-79) and RfBP (f182-204), suggesting that there was an optimum number of phosphate groups. Subsequently, the inhibitory activity of human β-casein phosphopeptides having 1-5 phosphate groups were examined. Human β-casein phosphopeptides having 4 and 5 phosphate groups showed the highest inhibitory activity.
The calcium absorption rate determined by the radioisotope method was in the order of casein diet > RfBP diet >soy protein diet. The soluble calcium percent in the small intestine was in the order of RfBP diet > casein diet > soy protein diet. These results suggested that phosphoprotein having higher calcium phosphate-solubilizing ability did not always show higher calcium absorption rate, and that there was an optimum number of phosphate groups in the calcium absorption-stimulating ability.
The method for the preparation micellar calcium phosphate (MCP)-phosphopeptides complex was established. The excellent bioavailability of MCP-phosphopeptides in rats was shown.
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