2004 Fiscal Year Final Research Report Summary
D-Amino acid synthetic enzyme of the mammalian origin
| Project/Area Number |
15590067
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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 |
Biological pharmacy
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| Research Institution | Kitasato University |
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Principal Investigator |
HOMMA Hiroshi Kitasato University, School of Pharmaceutical Sciences, Professor, 薬学部, 教授 (50190278)
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| Co-Investigator(Kenkyū-buntansha) |
HOMMA Hiroshi Kitasato University, School of Pharmaceutical Sciences, Professor (50190278)
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| Project Period (FY) |
2003 – 2004
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| Keywords | D-Aspartate / aspartate racemase / HPLC / fluorescent derivatization / enantioseparation / release / hyposmolarity / PC 12 cells |
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| Research Abstract |
D-Aspartate (D-Asp) is found in the mammalian neuroendocrine and endocrine tissues, and in now known to be involved in hormonal production and secretion. We have reported that D-Asp is produced in rat pheochromocytoma (PC) 12 cells. Although the precise synthetic pathway remains to be known in the cells, D-Asp in the microorganisms and the lower animals is presumed to be produced by Asp racemase. In this study, we developed a new HPLC system for rapid and sensitive assay of Asp racemase. We prepared a novel fluorogenic derivatization reagent (named BTCC), and developed a fully automated HPLC system. With this system, Asp racemase in hyperthermophilc archaea was easily and sensitively assayed.
The D-Asp efflux was also characterized in this study. We characterized two efflux pathways : 1) One of them is a spontaneous and continuous efflux pathway that requires extracellular Ca^<2+>. It is independent on the exocytotic pathway, since one of SNARE proteins is apparently not involved in this pathway. In addition, an inhibitor of voltage-dependent Ca^<2+> channel has no effect on the efflux, excluding the possible involvement of exocytosis in this pathway. 2) The other pathway is dependent on extracellular osmolarity. D-Asp is secreted by hyposmolarity stimuli. The efflux is presumed to be through a type of anion channel, based on its sensitivity to inhibitors. The efflux by hyposmolarity stimuli is further increased by an appropriate agonist stimulation.
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Research Products
(12 results)
