Cardiac alpha-crystallin. I. Isolation and identification.
Cardiac alpha-crystallin. I. Isolation and identification.
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心脏α-晶状体蛋白。
DOI：
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发表时间：
1990
影响因子：
4.3
通讯作者：
M. Chiesi
中科院分区：
文献类型：
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作者：
S. Longoni;P. James;M. Chiesi
一种水溶性蛋白质，大鼠心脏细胞的胞质组分的主要成分，纯化使用反相HPLC或抗体亲和层析程序和表征。该蛋白质具有24 K的表观Mr，通过SDS-凝胶电泳判断。然而，在非变性条件下，蛋白质作为单体24 kDa种类的同源多聚体（Mr在400和650 k之间）出现，并且可以通过在10至40%蔗糖梯度上对胞质级分进行分级而选择性地富集。多克隆抗体，提出了对变性的24 kDa的蛋白质，用于研究其组织分布。除了心脏，在那里它是非常丰富的，24 kDa的蛋白质也表达在其他红色肌肉和肾脏，但在胃，胸腺，肝脏和大脑中检测不到。测定了蛋白质的氨基酸组成和各种蛋白水解片段的部分氨基酸序列。对已知蛋白质的一级结构的同源性的研究表明，24 kDa蛋白质与α-B-晶状体蛋白即使不相同，也是惊人地相似。事实上，发现这两种蛋白质在免疫学标准上也是不可区分的。这项研究表明，透镜蛋白α B-晶状体蛋白是心脏细胞的主要胞质成分。
A water soluble protein, a major component of the cytosolic fraction of rat heart cells, was purified using either reverse phase HPLC or antibodies affinity chromatography procedures and characterized. The protein has an apparent Mr of 24 k, as judged by SDS-gel electrophoresis. Under non-denaturing conditions, however, the protein occurs as a homomultimer (Mr between 400 and 650 k) of the monomeric 24 kDa species and could be selectively enriched by fractionation of the cytosolic fraction on 10 to 40% sucrose gradients. Polyclonal antibodies, raised against the denatured 24 kDa protein, were used to investigate its tissue distribution. Besides the heart, where it is very abundant, the 24 kDa protein is expressed also in other red muscles and in kidneys, but was not detectable in stomach, thymus, liver, and brain. The amino acid composition of the protein and the partial amino acid sequence of various proteolytic fragments was determined. A search for homologies of the primary structure of known proteins has shown that the 24 kDa protein is strikingly similar, if not identical to alpha-B-crystallin. In fact, the two proteins were found to be indistinguishable also by immunological criteria. This study demonstrates that the lens protein alpha B-crystallin is a major cytosolic component of heart cells.