1990 Fiscal Year Final Research Report Summary
Preparation of the Protein Containing Very few Aromatic Amino Acid Residues by Ozonolysis of Protein
| Project/Area Number |
01860011
|
|---|
| Research Category |
Grant-in-Aid for Developmental Scientific Research (B).
|
| Allocation Type | Single-year Grants |
|---|
| Research Field |
応用生物化学・栄養化学
|
|---|
| Research Institution | Hokkaido University |
|---|
Principal Investigator |
KIRIYAMA. Shuhachi Hokkaido University, Faculty of Agriculture, Professor, 農学部, 教授 (00035396)
|
|---|
| Co-Investigator(Kenkyū-buntansha) |
KASAI Takanori Hokkaido University, Faculty of Agriculture, Associate Professor, 農学部, 助教授 (80001444)
|
|---|
| Project Period (FY) |
1989 – 1990
|
| Keywords | Ozonolysis of protein / Ozonolysis of aromatic amino acid / Protein containing no aromatic amino acid residue / Phenylketonuria / Disorders of aromatic amino acid metabolism / Beta-Aspartylurea |
|---|
| Research Abstract |
1) Protein containing no aromatic amino acid residue could be prepared by ozonolysis of protein in an aqueous solution.
2) Ozonated casein which contained very few amount of phenylalanine and no other aromatic amino acid residues was obtained by ozonolysis of casein in 8M urea solution (Casein is not soluble in water).
3) It was proved that addition of hydrogen peroxide solution to achieve oxidative decomposition of ozonide was unnecessary.
4) It was shown by feeding experiment of rats that ozonated casein had nearly the same protein efficiency ratio and biological value as casein, but significantly lower digestibility.
5) Urine of rats fed ozonated casein diet contained two unidentified ninhydrinpositive compounds (UN-1, major ; UN-2, minor) which was not detected in urine of casein fed group. UN-1 and UN-2 were identified as beta-aspartylurea and 4-methylproline (racemic), respectively.
6) It was confirmed that beta-aspartylurea was formed during ozonolysis of casein in 8M urea solution from aromatic amino acid residues. Origin of 4-methyl-proline is still obscure.
7) Beta-Aspartylurea in ozonated casein was hardly decomposed by the procedure used for hydrolysis of asparagine residue in protein.
8) A preliminary experiment indicated that casein sodium could be ozonized in an aqueous solution without urea.
|
