Yong Sik Boo

US Patent:

6989143, Jan 24, 2006

Filed:

May 2, 2000

Appl. No.:

10/275195

Inventors:

Chan Hyung Park - Federal Way WA, US
Yong C. Boo - Birmingham AL, US

Assignee:

Jin Yang Pharm Co., Ltd. - Seoul

International Classification:

A61K 38/44

US Classification:

424 944, 435181

Abstract:

Artificial modulation of ascorbate level was investigated in mice capable of de novo synthesis of ascorbate. When mice were given exogenous ascorbate or its physiological precursor, L-gulono-γ-lactone, the plasma level of ascorbate was elevated substantially but immediately returned to the basal levels. Comparably, the administration of ascorbate oxidase caused a rapid disappearance of plasma ascorbate but followed by an immediate restoration of ascorbate. These results indicate the difficulties encountered in the modulation of ascorbate level in the animal. However, the circulation life of the exogenous ascorbate oxidase in the animal was successfully extended by chemical modification with methoxypolyethylene glycol. The modified enzyme retained a full activity and exerted a remarkably prolonged depletion of plasma ascorbate compared with the native enzyme. This study suggests that the chemically modified ascorbate oxidase should find many uses in the animal studies on ascorbate since it was found to deplete plasma ascorbate even in the ascorbate-synthesizing animal in the absence of dietary control.