巻号一覧
82 巻, 2 号
選択された号の論文の8件中1～8を表示しています
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八木 年晴原稿種別: 本文
2008 年 82 巻 2 号 p. 87-99
発行日: 2008/02/25
公開日: 2017/10/10
ジャーナル フリーVitamin B_6, consisting of natural six forms, pyridoxine, pyridoxal, pyridoxamine and their 5'-phosphate forms, functions as the essential nutrient through supporting the enzymes involved in metabolisms of amino acids and others as a coenzyme. They nutritionally show the same efficiency, because they can be interchangeable through a salvage pathway to form the coenzyme form, pyridoxal 5'-phosphate. In contrast, recent works show that the individual form has a specific function, such as anti-active carbonyl and antioxidation ones. We have found that vitamin B_6 compounds protected fission yeast cells against oxidative death more efficiently than vitamin C, and inhibited tyrosinase reaction by scavenging reactive oxygen specie(s) essential for the enzyme reaction. The genes encoding enzymes involved in the metabolism of vitamin B_6 compounds were identified, and structures and functions of the enzymes were elucidated. Pyridoxal reductase in the fission yeast cells was a new member of aldo-keto reductase superfamily, and suggested to be involved in an efflux system of pyridoxal after reducing to pyridoxine. All of genes involved in the degradation for vitamin B_6 were identified. They located on a chromosome of Mesorhizobium loti, a nitrogen-fixing symbiotic microorganism, as a cluster. The enzymes were over-expressed and characterized. E. coli cells containing the high amount of the enzymes were used for bioconversion of pyridoxine to 4-pyridoxolactone. Three of the enzymes were applied to a new individual determination method of vitamin B_6 compounds.抄録全体を表示PDF形式でダウンロード (1975K) -
生城 浩子原稿種別: 本文
2008 年 82 巻 2 号 p. 101-114
発行日: 2008/02/25
公開日: 2017/10/10
ジャーナル フリーSerine palmitoyltransferase (SPT) is a key enzyme of sphingolipid biosynthesis and catalyzes the decarboxylative condensation of L-serine with palmitoyl-CoA to form 3-ketodihydrosphingosine. Eukaryote SPTs are known as heterodimers composed of tightly membrane-bound subunits, which makes their detailed analysis difficult. Therefore, as the alternative enzyme source, we focused into the bacteria that contain a large amount of sphingolipid as their cellular component. We have purified a water-soluble homodimeric SPT from Sphingomonas paucimobilis 2395^T first, then cloned SPT genes from several bacterial species and have overproduced them in E. coli. Using these bacterial enzymes, the reaction mechanism of SPT was analyzed in detail and X-ray crystallographic analysis of its structure in a complex with the amino acid substrate, L-serine were performed. These results allow us to understand the structure-function relationship of eukaryote SPT.抄録全体を表示PDF形式でダウンロード (1931K) -
柴田 克己, 福渡 努原稿種別: 本文
2008 年 82 巻 2 号 p. 115-125
発行日: 2008/02/25
公開日: 2017/10/10
ジャーナル フリーIn Japan, two basic texts are used for nutritional guidance, Standard Tables of Food Composition in Japan and Dietary Reference Intakes for Japanese, 2005. The "Food Composition Tables" describe the nutrient values of foods, and "Dietary Reference Intakes" reports the values that humans can use. Synthetic vitamins have been often used in experiments to determine vitamin requirements, and the bioavailability of synthetic vitamins is considered to be 100%. However, the bioavailability of a vitamin from foods may not be 100% because most vitamins existing in nature are bound to proteins, sugars, or other compounds. Although it is necessary to determine the bioavailability of vitamins in food consumed, no method has been established. We introduce a practical method to determine the bioavailability of vitamins in food. In particular, we are also interested in the effects the dietary intake of minerals and micronutrients exerts on the bioavailability of vitamins. We believe that the results of these studies will contribute to the maintenance of public health in Japanese.抄録全体を表示PDF形式でダウンロード (1037K) -
木川 真理, 片岡 伸介原稿種別: 本文
2008 年 82 巻 2 号 p. 127-130
発行日: 2008/02/25
公開日: 2017/10/10
ジャーナル フリーIn vivo evaluating model is accepted as a powerful tool for determining pharmaceutical effects and safe dosage for clinical use. We established the animal model for evaluating the inflammation caused by reactive oxygen species (ROS). Croton oil (CRO) was topically applied to induce ROS-derived inflammation on the guinea pig skin. Visual inspection of the erythema was performed on 24h after application to evaluate the CRO-induced skin response on a score of one to six. Ascorbate-2-phosphate (AP), ascorbic acid derivative, has been reported to be a potent antioxidant action. To examine its effect on this model, AP was applied topically after CRO application. The inflammation score was significantly reduced by 32-52% of that in the control group. Histological evaluation revealed that AP also decreased the inflammatory thickening and the expression of the oxidative stress marker, 8-hydroxy-2'-deoxyguanosine (8-OHdG) in the skin. These results show the CRO-induced inflammation model developed here is useful tool for evaluating anti-inflammatory and antioxidant effects.抄録全体を表示PDF形式でダウンロード (1087K) -
柴田 克己, 廣瀬 潤子, 福渡 努, 肥田 嘉文, 國松 孝男原稿種別: 本文
2008 年 82 巻 2 号 p. 131-135
発行日: 2008/02/25
公開日: 2017/10/10
ジャーナル フリーThe blood NAD(H) level varies with animal species, whereas the blood NADP(H) concentration is the same in all animal species. Because little is known about the blood NAD(H) and NADP(H) concentrations in water animals, we investigated the concentrations of both in nigorobuna, Carassius auratus grandoculis. Fifty nigorobuna (0+years old) were harvested from Lake Biwa, Seventeen of them were aquacultured and then released into the lake, 9 of them were transferred to a paddy field for one or two months after hatching and then released into the lake, and 24 of them were born and grew up in the natural environment. The blood NAD(H) concentration in nigorobuna was approximately 80nmol/mL, which is almost the same as that of rats and 2.5 times higher than that of humans. The blood NADP(H) concentration in nigorobuna was approximately 2.5nmol/mL, which is one fourth of the values in rats and humans. There were no differences in blood NAD(H) and NADP(H) levels by sex or life history in nigorobuna.抄録全体を表示PDF形式でダウンロード (604K) -
田鶴谷(村山) 恵子, 山田 和子, 三嶋 基弘原稿種別: 本文
2008 年 82 巻 2 号 p. 137-139
発行日: 2008/02/25
公開日: 2017/10/10
ジャーナル フリーPDF形式でダウンロード (363K) -
五十嵐 庸, 加藤 茂明原稿種別: 本文
2008 年 82 巻 2 号 p. 140-141
発行日: 2008/02/25
公開日: 2017/10/10
ジャーナル フリーPDF形式でダウンロード (266K) -
近藤 寛樹原稿種別: 本文
2008 年 82 巻 2 号 p. 142-
発行日: 2008/02/25
公開日: 2017/10/10
ジャーナル フリーPDF形式でダウンロード (137K)
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