1990 Fiscal Year Final Research Report Summary
Chemistry on Peptides Induced in Plants Treated with Cadmium Ion
| Project/Area Number |
01560146
|
|---|
| Research Category |
Grant-in-Aid for General Scientific Research (C)
|
| Allocation Type | Single-year Grants |
|---|
| Research Field |
製造化学・食品
|
|---|
| Research Institution | Mie University |
|---|
Principal Investigator |
IMAI Kunio Mie University, Bioresources, Associate Professor, 生物資源学部, 助教授 (80109313)
|
|---|
| Co-Investigator(Kenkyū-buntansha) |
OBATA Hitoshi Mie University, Bioresources, Associate Professor, 生物資源学部, 助教授 (70024594)
|
|---|
| Project Period (FY) |
1989 – 1990
|
| Keywords | Cadystins / HPLC / Specific Detection / Cadmium Ion / Glutathione / Carboxypeptidase / Enzymic Synthesis |
|---|
| Research Abstract |
Cadystins had been found in a fission yeast treated with cadmium ion. Their structures are characteristic to contain gamma-glutamyl-cysteine moiety and had been determined by means of micro-chemical reactions and enzymic reactions.
During the present research, two methods to analyze cadystins specifically were established. One of them is HPLC analysis of fluorescent DACM derivatives of cadystins. The other one is HPLC analysis of their 4-vinylpyridine derivatives bearing specific UV absorbance at 255 nm. Although the sensitivity of the latter is not better than the former, the latter method was suitable to analyze the molecular species of cadystins because the derivate formation reaction afforded a single product corresponding to the respective cadystins and because the derivatives are stable enough during the analysis. The former method is suitable to detect trace amount of cadystins,because it is more highly sensitive than the latter. The former method was applied to determine cadysti
… More
ns induced in the root of rice plant treated with Cd^<++>. The results suggested that glutathione (GSH) is the major SH peptide in non-treated root, and that cadystins were newly induced accompanied by dramatic decrease of GSH, by treatment with Cd^<++>.
Next, the enzymic synthesis of cadystins was examined. An interesting specificity of carboxypeptidase (CPase) found in the structure analysis was applied for this purpose. That is the specificity that CPase does not cleave gamma-Glu-Cys bond and that it cleaves Cys-Gly and Cys-Glu linkage. GSH was treated with CPase Y under a high substrate concentration condition. The enzymic reaction afforded major 6 products. Two of them were cadystin (gamma EC)_2G and (gamma EC)_3G. The other products were (gamma EC), (gamma EC)_2, (gamma EC)_3, and dehydrate product of (gamma EC)_2. The results suggested the major metabolic pathway of GSH by CPase Y under high substrate concentration condition and a method to synthesize cadystins in a simgle step was established. Less
|
