The characterization of soluble amyloid prepared in water.
The characterization of soluble amyloid prepared in water.
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水中制备的可溶性淀粉样蛋白的表征。
DOI：
10.1172/jci105784
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发表时间：
1968
期刊：
影响因子：
--
通讯作者：
E. Franklin
中科院分区：
文献类型：
--
作者：
M. Pras;M. Schubert;D. Zucker‐Franklin;A. Rimon;E. Franklin
从原发性淀粉样变性患者的脾脏中提取淀粉样蛋白，经初步处理后，首先除去可溶于盐水的蛋白质，然后除去盐，用水高速离心。含有淀粉样蛋白的提取物在蛋白质浓度高达6 mg/ml时似乎是透明的。当离心至20，000 g时，该物质几乎没有沉淀，但当离心至100，000 g时，蛋白质在1小时内沉淀。通过加入NaCl至0.0075摩尔/升或CaCl（2）至0.0025摩尔/升，可以从提取物中沉淀出淀粉样蛋白。蛋白质结合的刚果红形成红色沉淀，该性质用于估计提取过程中淀粉样蛋白的回收率和纯度。在电子显微镜下，分离的淀粉样蛋白被证明是形态纯的。它以直径为60-80 A的单丝或这些单丝的大聚集体存在。新鲜分离的淀粉样蛋白在水中沉积为单一均匀峰，s度（20，[未知]）约为45- 50 S。静置后，溶液变得浑浊，并出现更快速沉降的组分。在电泳中，材料作为均匀峰向阳极迁移。该蛋白质的氨基酸组成不同于所有已知的血清蛋白质。富含酸性氨基酸，半胱氨酸和蛋氨酸含量低，不含羟脯氨酸。碳水化合物总含量小于2%。
Amyloid was extracted from the spleen of a patient with primary amyloidosis by homogenizing it at high speed with water after preliminary treatments, first to remove proteins soluble in saline, and then to remove salts. The extracts containing amyloid appeared to be clear at concentrations up to 6 mg/ml of protein. The material gave little sediment on being centrifuged up to 20,000 g for 1 hr, but the protein was sedimented at 100,000 g in 1 hr. The amyloid could be precipitated from the extracts by addition of NaCl to 0.0075 mole/liter or of CaCl(2) to 0.0025 mole/liter. The protein-bound Congo red formed a red precipitate and this property was used to estimate recovery and purity of amyloid during extraction. On electronmicroscopy the isolated amyloid proved to be morphologically pure. It existed either as single filaments measuring 60-80 A in diameter or as large aggregates of these filaments.Freshly isolated amyloid in water sedimented as a single homogeneous peak with an s degrees (20,[unk]) of about 45-50S. On standing, the solution became cloudy and more rapidly sedimenting components appeared. On electrophoresis the material migrated as a homogeneous peak towards the anode. The protein had an amino acid composition different from that of all known serum proteins. It was rich in acidic amino acids and had little cysteine and methionine and no hydroxyproline. The total content of carbohydrate was less than 2%.