ISOLATION AND CHARACTERIZATION OF AN UNKNOWN, LEUCINE-RICH 3.1S-ALPHA2-GLYKOPROTEIN FROM HUMAN-SERUM
ISOLATION AND CHARACTERIZATION OF AN UNKNOWN, LEUCINE-RICH 3.1S-ALPHA2-GLYKOPROTEIN FROM HUMAN-SERUM
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DOI：
10.1515/bchm2.1977.358.1.639
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发表时间：
1977-01-01
影响因子：
--
通讯作者：
BAUDNER, S
中科院分区：
文献类型：
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作者：
HAUPT, H;BAUDNER, S
先前未知的富含亮氨酸的3.1S- α的分离和鉴定。描述了人血清中的2-糖蛋白。以大规模制备白蛋白和γ的副产物上清II为起始原料。用乳酸乙吖啶/硫酸铵法测定-球蛋白。纯化后的蛋白在无载体电泳和分子筛电泳中均呈均匀性。其电泳迁移率表明它属于α 2-球蛋白。等电聚焦将其分为4个波段，等电点在3.8 - 4.1之间。在超离心机中，它在3.1S时呈单带沉积。平衡沉降测定的MW为49,600 +-。4000. 未检测到亚基。化学分析表明它是一种糖蛋白，碳水化合物含量为23%。氨基酸含量的不同寻常之处在于亮氨酸含量几乎达到17%，即大约每5个氨基酸中就有一个是亮氨酸。富亮氨酸的平均浓度为3.1S- α。用定量免疫学方法测定人血清2-糖蛋白含量为2.1 mg/100 ml，该蛋白与以往已知的已表征的血清蛋白均无相关性。
The isolation and characterization of a previously unknown, leucine-rich 3.1S-.alpha.2-glycoprotein from human serum is described. The starting material was Supernatant II, which is a byproduct in the large-scale preparation of albumin and .gamma.-globulin by the ethacridine lactate/ammonium sulfate procedure. The purified protein is homogeneous both in carrier-free and molecular-sieve electrophoresis. Its electrophoretic mobility indicates that it belongs to the .alpha.2-globulins. Isoelectric focusing splits it into 4 bands with isoelectric points between 3.8 and 4.1. In the ultracentrifuge, it sediments in a single band at 3.1S. The MW determined by equilibrium sedimentation is 49,600 .+-. 4000. Subunits were not detected. Chemical analysis reveals it to be a glycoprotein with a carbohydrate content of 23%. The amino acid content is unusual in that the leucine content is almost 17%, i.e., about every 5th amino acid is a leucine. The average concentration of the leucine-rich 3.1S-.alpha.2-glycoprotein in human serum was determined by a quantitative immunological method as 2.1 mg/100 ml. The protein is not related to any of the previously known well characterized serum proteins.