权益分类	功能权益	普通用户	{{item.name}}会员
{{category.name}}	{{benefitItem.name}}

Studies on Enzyme System of Tryptophan Metabolism in Fish Liver

鱼肝色氨酸代谢酶系统的研究

基本信息

批准号：
01560220
负责人：
NAGAYAMA Fumio
金额：
$ 1.34万
依托单位：
Tokyo University of Fisheries
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (C)
财政年份：
1989
资助国家：
日本
起止时间：
1989 至 1990
项目状态：
已结题

项目摘要

1. Several enzymes which are involved in the metabolism of tryptophan in fish liver were investigated.2. It is known that the kynurenine pathway is the major route in tryptophan metabolism in animals. The activity of fish liver tryptophan pyrrolase which catalyzes the first step in kynurenine pathway was comparatively low, and it was not activated by hematin.3. Arylformamidase, the second enzyme in kynurenine pathway, of the rainbow trout liver was purified and its properties were compared to those of the cattle enzyme. The fish enzyme was inhibited by tryptophan. This suggests that the kynurenine pathway of fish is regulated by tryptophan, the first substrate of the pathway.4. The ratio of hydroxyanthranillate oxygenase activity to aminocarboxymuconic semialdehyde decarboxylase activity indicated that the NAD-forming pathway is exceedingly inefficient in the rainbow trout.5. Fish liver extract exhibited an apparent activity of tryptophan hydroxylase, the first enzyme in the serotonine pathway. The Km value of hydroxylase to tryptophan was lower than that of pyrrolase. It appears that the importance of the serotonine pathway exceeds that of the kynurenine pathway.

1.对鱼类肝脏中参与色氨酸代谢的几种酶进行了研究.已知犬尿氨酸途径是动物中色氨酸代谢的主要途径。催化犬尿氨酸途径第一步的鱼肝色氨酸吡咯酶活性较低，不被血红素激活.对虹鳟鱼肝脏中犬尿氨酸途径中的第二种酶--芳基甲酰胺酶进行了纯化，并将其性质与牛的酶进行了比较。色氨酸对鱼酶有抑制作用。这表明鱼的犬尿氨酸途径是由色氨酸调节的，色氨酸是该途径的第一底物。羟基邻氨基苯甲酸加氧酶活性与氨基羧基粘康酸半醛脱羧酶活性的比值表明，在虹鳟鱼中NAD形成途径的效率极低.鱼肝提取物表现出色氨酸羟化酶的表观活性，色氨酸羟化酶是色氨酸途径中的第一个酶。羟化酶对色氨酸的Km值低于吡咯酶。看来，腺苷三磷酸途径的重要性超过犬尿氨酸途径。