AMYLOID FIBRILS DERIVED FROM V-REGION TOGETHER WITH C-REGION FRAGMENTS FROM A LAMBDA-II-IMMUNOGLOBULIN LIGHT CHAIN (HAR)
AMYLOID FIBRILS DERIVED FROM V-REGION TOGETHER WITH C-REGION FRAGMENTS FROM A LAMBDA-II-IMMUNOGLOBULIN LIGHT CHAIN (HAR)
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DOI：
10.1515/bchm3.1985.366.2.907
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发表时间：
1985-01-01
期刊：
影响因子：
--
通讯作者：
LINKE, R
中科院分区：
文献类型：
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作者：
EULITZ, M;LINKE, R
通过在5M盐酸胍中提取和凝胶过滤从患有IgD(λ)-浆细胞瘤的患者的脾中分离淀粉样纤维蛋白。主要多肽链的分子量约为5000 Da。通过羧甲基化多肽链的逐步自动降解以及胰蛋白酶和热溶酶裂解产物的结构研究阐明了其完整的氨基酸序列。该多肽链长度为58至59个残基，与λ型免疫球蛋白轻链可变部分的第8至65位氨基酸同源，与λII亚群关系最密切。该淀粉样原纤维蛋白的N端序列被证明是异质的，表明在位置7和8的氨基酸之后发生裂解。在变性淀粉样蛋白HAR的胰蛋白酶消化中意外地发现了来自λ-链恒定部分的肽。通过高效液相色谱法将来自恒定区的一种多肽与主要成分分离。其氨基酸序列从第 111 位开始，可追踪 41 个步骤。在这种情况下，至少两个恒定区片段被证明是淀粉样原纤维蛋白的组成部分。关于淀粉样蛋白的形成，讨论了来自可变区和恒定区的片段的关联。
Amyloid fibrin proteins were isolated from the spleen of a patient with IgD(.lambda.)-plasmocytoma by extraction and gel filtration in 5M guanidine hydrochloride. The molecular mass of the predominant polypeptide chain was approximately 5000 Da. Its complete amino-acid sequence was elucidated by stepwise automated degradation of the carboxymethylated polypeptide chain and by structural studies of tryptic and thermolysinolytic cleavage products. The length of the polypeptide chain was 58 to 59 residues and it was homologous to the amino acids in positions 8 through 65 of the variable part of an .lambda.-type immunoglobulin light chain, which was most closely related to the .lambda.II subgroup. The N-terminal sequence of this amyloid fibril protein proved to be heterogeneous, indicating cleavage after the amino acids in positions 7 and 8. Peptides from the constant part of the .lambda.-chain were unexpectedly found in the tryptic digest of the denatured amyloid protein HAR. One polypeptide derived from the constant region was separated from the main component by high performance liquid chromatography. Its amino-acid sequence commenced at position 111 and could be traced in 41 steps. In this case, at least two constant region fragments were shown to be constitutents of the amyloid fibril protein. The association of fragments from the variable as well as the constant region is discussed with respect to amyloid formation.