Elucidation of Prorerties and Physiological Roles of nicoinamide-Biding Protein, and It's Applocation to the Determination of Vitamin

烟酰胺结合蛋白的性质和生理作用的阐明及其在维生素测定中的应用

• 批准号: 04660083
• 负责人: TAGUCHI Hiroshi
• 金额: $ 0.45万
• 依托单位: Mie University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C).
• 财政年份: 1992
• 资助国家: 日本
• 起止时间: 1992 至 1993
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-04660083/
• 关键词: vitamin; binding protein; nicotinamide; nicotinic acid; niacin; N-methylnicotinamide; hog liver; rat liver; ニコチンアミド結合タンパク質

Various vinding proteins (BP) specific to each vitamin are kyown, but the BP specific to free nicotinic acid(NiA) or free nicotinamide (NAm) is not known. Accordingly we investigated such protein and finally we have just found NAm specific BP (NAm-BP). Hence various properties of this protein in hog liveer and in various organs in rat, and effects of niacin-related compounds were investigated. As the results, followings are confirmed.After the experimental diets of NAm-deficient, control, and excess NAm are fed to rats for 2 weeks ad libitum, the activities of NAm-BP were determined. the activities in almost all organs including liver and kidney were higher than those in organs of control group. It is suggested that the ability of NAm binding of NAm-BP is changed according to the amount of NAm in bodies. Cogactor for the binding was also found in the extract from hog liver and the properties of it were as follows : molecular weight, less than 10000 ; stability, heat stable ; acid and aldali labile ; charge, neutral. Exchange of NAm on NAm-BP was obseved when exess NAm was added. NAm-bindin ability was greately lowered with MNA and 2-Py. As these compounds were excreted in urine as final products from NAm catabolism, it is suggested tha NAm is supplied according to the decrease of NAm in the body.Application of this NAm-BP to the determination of vitamin could not be done, because of shortage of time.

每种维生素所特有的各种蛋白质（BP）是已知的，但对游离烟酸（NiA）或游离烟酰胺（NAm）的特异性BP是未知的。因此，我们对这种蛋白进行了研究，最终发现了NAm特异性BP （NAm-BP）。因此，研究了该蛋白在猪肝和大鼠各器官中的各种特性，以及烟酸相关化合物的作用。作为结果，确认如下：给大鼠随意饲喂NAm缺乏、对照和过量实验饲料2周后，测定NAm- bp的活性。肝、肾等各脏器活性均高于对照组。提示NAm- bp结合NAm的能力随体内NAm含量的变化而变化。在猪肝提取物中也发现了结合的辅助因子，其性质如下：分子量小于10000；稳定性、热稳定性；酸和醛不稳定；电荷,中性的。添加过量的NAm时，NAm- bp上的NAm发生交换。MNA和2-Py显著降低了na -结合能力。由于这些化合物作为NAm分解代谢的最终产物从尿液中排出，因此建议NAm是根据体内NAm的减少而供应的。由于时间有限，尚不能将该纳米bp应用于维生素的测定。

项目成果

田口 寛 ら: "Findings of Nicotinamide-Binding Proteins in Various Mammalian Tissues and Geneneval Properties of the Protein in Hog Liver" Biosci.Biotech.Biochem.57. (1993)

Hiroshi Taguchi 等人：“各种哺乳动物组织中烟酰胺结合蛋白的发现和猪肝脏中蛋白质的基因特性”Biosci.Biotech.Biochem.57（1993）。