Scientia Sinica最新文献_第6页

Presence of a cytochrome b-containing ferritin in Azotobacter vinelandii. 含细胞色素b的铁蛋白在黄氏固氮菌中的存在。

Scientia Sinica Pub Date : 1980-07-01

J D Li, J W Wang, Z P Zhong, Y Tu, B Dong

{"title":"Presence of a cytochrome b-containing ferritin in Azotobacter vinelandii.","authors":"J D Li, J W Wang, Z P Zhong, Y Tu, B Dong","doi":"","DOIUrl":"","url":null,"abstract":"It has been demonstrated that a cytochrome b-containing ferritin is present in Azotobacter vinelandii. After DEAE cellulose chromatography and purification fractional precipitation by 50% of the saturated ammonium sulfate of the extract prepared from A. vinelandii cells, a hexagonal crystalline preparation is obtained. The protein contains 4--6% of nonheme iron. The protein molecule is made up of an electron dense iron core with a diameter of 70A and a protein shell with a diameter of 120A. The Fe core can be removed from the shell by the treatment with chelating and reducing agents. Electron micrographs and absorption spectra reveal that the protein shells are very similar before and after the removal of the core. The electrophoretic mobility and immunological properties of the Fe-free protein against the antibody of ferritin are very similar to those of the protein before the removal of the iron. From the above characteristics, it can be inferred that the protein belongs to ferritin. The protein part contains protoheme as prosthetic group and so it belongs to cytochrome b. Hence, the protein prepared from A. vinelandii is a kind of cytochrome b-containing ferritins. The possible role of the ferritin in biological nitrogen fixation is discussed in this paper.","PeriodicalId":21694,"journal":{"name":"Scientia Sinica","volume":"23 7","pages":"897-904"},"PeriodicalIF":0.0,"publicationDate":"1980-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"18455034","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Female cadaver in the Han Tomb No. 1. X-ray diffraction studies on two kinds of fibrous protein. 汉墓1号女尸。两种纤维蛋白的x射线衍射研究。

Scientia Sinica Pub Date : 1980-07-01

B M Wu, J H Wang

引用次数: 0

Observations on Baiji (Lipotes vexillifer) and finless porpoise (Neophocaena asiaeorientalis) in the lower reaches of the Chang Jiang. 长江下游白暨豚(Lipotes vexillifer)和江豚(Neophocaena asiaeorientalis)的观察。

Scientia Sinica Pub Date : 1980-06-01

K Y Zhou, G Pilleri, Y M Li

{"title":"Observations on Baiji (Lipotes vexillifer) and finless porpoise (Neophocaena asiaeorientalis) in the lower reaches of the Chang Jiang.","authors":"K Y Zhou, G Pilleri, Y M Li","doi":"","DOIUrl":"","url":null,"abstract":"Lipotes usually occurs in pairs or in small loose groups. The calves are born in March-April. The Finless porpoises are usually seen in groups of five or six individuals. The blow of Lipotes lasts 0.2-0.6 sec and that of Neophocaena 0.2-0.5 sec. In Lipotes, a short dive would take 10-20 sec and a long dive up to 1-2 min (average value being 31 sec). In Neophocaena a long dive would reach a maximum of 65 sec with an average of 17.5 sec. Lipotes has a pair of functional eyes. The selective secondary atrophy of a number of eye muscles and nerves and the position of the eyes in the head correspond with the physical conditions of the environments, so that the field of vision is directed forwards and upwards. When pursued by motor boat, both species react with a long dive and a change of direction under water. With the Baiji this would occasionally cause fatal injuries by the propeller of the ship. Such a case seems much less often with Neophocaena. The population of Lipotes is at present very small. In the stretch of the river (between Nanjing and Taiyangzhou) under exploration, we found scarcely more than one dolphin per 4 km. The cause for its scarcity is mostly due to accidents or wounds caused by propellers.","PeriodicalId":21694,"journal":{"name":"Scientia Sinica","volume":"23 6","pages":"785-94"},"PeriodicalIF":0.0,"publicationDate":"1980-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"18424039","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Effects of reserpine on the development of neuropsychogenic hypertension in dogs. 利血平对犬神经心因性高血压的影响。

Scientia Sinica Pub Date : 1980-06-01

G Y Zeng, S Y Xie, S Q You, Y C Jin

引用次数: 0

The measurement of audiometric zero level of air conduction. 空气传导的听觉零电平的测量。

Scientia Sinica Pub Date : 1980-06-01

J C Zhang, Y C Deng, G X Wen

引用次数: 0

Antispermatogenic effect of gossypol on the germinal epithelium of the rat testes. A cytological, autoradiographical and ultrastructural observation. 棉酚对大鼠睾丸生殖上皮的抗生精作用。细胞学、放射自显影和超微结构观察。

Scientia Sinica Pub Date : 1980-05-01

X Shepu, Z Shudong, S Shuyun, W Yanwan, L Yi, Z Zenghua, M Xixin