Identification of proteolytically resistant domains of human erythrocyte spectrin.
Identification of proteolytically resistant domains of human erythrocyte spectrin.
复制标题
人红细胞血影蛋白的蛋白水解抗性结构域的鉴定。
DOI：
10.1073/pnas.77.10.5673
复制
发表时间：
1980
影响因子：
11.1
通讯作者：
Marchesi,VT
中科院分区：
文献类型：
--
作者：
Speicher,DW;Morrow,JS;Knowles,WJ;Marchesi,VT
用蛋白水解酶在0℃下消化纯化的人红细胞光谱蛋白，产生中等大小的肽，可以抵抗在0℃下进一步切割。通过对这些中间肽的二维肽分析，已经确定了5种独特的肽是由光谱蛋白α亚基的胰蛋白酶切割产生的（波段1）；它们的表观分子量分别为80,000、46,000、46,000、41,000和30,000，占α亚基的97%。同样，四种独特的肽，其表观分子量分别为74,000,65,000,33,000和38,000，占β亚基（波段2）的90%。通过检查较大的肽片段，沿着每个谱蛋白亚基的独特肽的线性排列已经建立。这些结果表明，spectrin由两个不相同的亚基组成，每个亚基都含有多个蛋白水解抗性结构域。这些结构域可能大部分是螺旋状的，似乎是由蛋白酶敏感的小片段连接起来的。这些结构域的蛋白水解抗性不受谱蛋白分子多聚态的影响。
Digestion of purified human erthrocyte spectrin with proteolytic enzymes at 0 degrees C results in the production of intermediate-size peptides that resist further cleavage at 0 degrees C. By two-dimensional peptide analysis of these intermediate peptides it has been determined that five unique peptides are produced by tryptic cleavage of the alpha subunit of spectrin (band 1); these have apparent molecular weights of 80,000, 46,000, 46,000, 41,000, and 30,000 and account for 97% of the alpha subunit. Similarly, four unique peptides having apparent molecular weights of 74,000, 65,000, 33,000, and 38,000 account for 90% of the beta subunit (band 2). By examining larger peptide fragments, the linear alignment of the unique peptides along each of the spectrin subunits has been established. These results indicate that spectrin is composed of two nonidentical subunits, each containing multiple proteolytically resistant domains. These domains, which may be largely alpha-helical, seem to be connected by small protease-sensitive segments. The proteolytic resistance of these domains is not influenced by the multimeric state of the spectrin molecule.