Francis S H, Leslie R G, Hood L, Eisen H N
Proc Natl Acad Sci U S A. 1974 Apr;71(4):1123-7. doi: 10.1073/pnas.71.4.1123.
Cyanogen bromide cleavage of the heavy (alpha) chain of protein 315 (an immunoglobulin A mouse myeloma protein with anti-dinitrophenyl activity) yielded five fragments of which one (CN2), with 156 residues, contained the chain's entire variable region. Determination of the amino-acid sequence of CN2 showed that: (1) the variable region has appreciable homology (about 33% identities) with the variable region of the light chain from the same molecule; and (2) the constant-region sequence immediately following the probable transition from variable to constant domains is the same in the protein-315 alpha as in human gamma1 and mu chains (-Val-Ser-Ser-). The sequence of the cyanogen bromide octapeptide (CN5) from the carboxy terminus of the protein-315 heavy chain closely resembles the corresponding segments of human alpha and mu chains.
对蛋白315(一种具有抗二硝基苯基活性的免疫球蛋白A小鼠骨髓瘤蛋白)的重(α)链进行溴化氰裂解,产生了五个片段,其中一个片段(CN2)有156个残基,包含该链的整个可变区。对CN2氨基酸序列的测定表明:(1)该可变区与同一分子轻链的可变区具有明显的同源性(约33%的同一性);(2)在可能从可变结构域向恒定结构域转变之后紧接着的恒定区序列,在蛋白315α链中与人γ1和μ链中的相同(-Val-Ser-Ser-)。来自蛋白315重链羧基末端的溴化氰八肽(CN5)的序列与人类α链和μ链的相应片段非常相似。