Frangione B, Wolfenstein-Todel C
Proc Natl Acad Sci U S A. 1972 Dec;69(12):3673-6. doi: 10.1073/pnas.69.12.3673.
The aminoacid sequence of the "hinge" region of two human IgA(1) myeloma proteins was found to be identical. A 30-residue fragment contains 3 cysteines, 12 prolines, and carbohydrate, and the sequence of a small segment of the hinge region is repeated at least twice. Since a deletion of 12-13 residues was found in the same region of an IgA(2) myeloma protein, it is possible that IgA(1) molecules are the result of the insertion of a partially duplicated gene segment in the immunoglobulin genes.
发现两种人IgA(1)骨髓瘤蛋白“铰链”区的氨基酸序列相同。一个30个残基的片段含有3个半胱氨酸、12个脯氨酸和碳水化合物,并且铰链区一小段的序列至少重复两次。由于在一种IgA(2)骨髓瘤蛋白的同一区域发现了12 - 13个残基的缺失,因此IgA(1)分子有可能是免疫球蛋白基因中部分重复基因片段插入的结果。