Svehag S E, Bloth B
Science. 1970 May 15;168(3933):847-9. doi: 10.1126/science.168.3933.847.
Electron micrographs of immunoglobulins A from human and rabbit colostrum, which were purified on tall agarose columns, revealed Y-shaped molecules (125 by 140 angstroms). The linear dimensions of the arms were 55 to 75 by 25 to 30 angstroms. A molecular model is postulated in which two immunoglobulin A monomers are superimposed on each other in a close-packed state with the secretory piece inserted in the constant region of the alpha-chains. High-polymer (11 or 13S) immunoglobulin A molecules (total span 100 to 110 angstroms) from human serum were composed of four arms (50 to 55 by 20 angstroms) joined at a contrast-rich center.
对在高琼脂糖柱上纯化的人及兔初乳中的免疫球蛋白A进行电子显微镜观察，发现其呈Y形分子（125×140埃）。其臂的线性尺寸为55至75×25至30埃。推测出一种分子模型，其中两个免疫球蛋白A单体以紧密堆积状态相互叠加，分泌片段插入α链的恒定区。人血清中的高聚物（11或13S）免疫球蛋白A分子（总跨度100至110埃）由四个臂（50至55×20埃）在富含对比度的中心相连组成。
