Hultmark D, Engström A, Andersson K, Steiner H, Bennich H, Boman H G
EMBO J. 1983;2(4):571-6. doi: 10.1002/j.1460-2075.1983.tb01465.x.
Six closely related antibacterial proteins, attacins A-F, were isolated from the hemolymph of immunized pupae of the Cecropia moth, Hyalophora cecropia. Chromatofocusing separated attacins A-F, with isoelectric points between 5.7 and 8.3. Immunological experiments show that the attacins constitute antibacterially active forms of the previously isolated inducible immune protein P5. Their mol. wts., 20-23 K, are similar to that of protein P5, but significantly lower than 28 K found for preP5 synthesized in vitro (see accompanying paper). The six attacins can be divided into two groups according to their amino acid composition and amino-terminal sequences, attacins A-D constitute a basic group and attacins E and F an acidic one. Within each group the forms are very similar. The attacins efficiently killed Escherichia coli and two other Gram-negative bacteria isolated from the gut of a silk worm but they did not act on other Gram-positive and Gram-negative bacteria tested. Only growing cells of E. coli were attacked; cells suspended in phosphate buffer were inert. Besides the cecropins and lysozyme, the attacins represent a third class of antibacterial proteins in the humoral immune system of H. cecropia.
从大透目天蚕蛾（Hyalophora cecropia）免疫蛹的血淋巴中分离出六种密切相关的抗菌蛋白，即攻击素A - F。层析聚焦法分离出攻击素A - F，其等电点在5.7至8.3之间。免疫学实验表明，攻击素构成了先前分离的可诱导免疫蛋白P5的抗菌活性形式。它们的分子量为20 - 23K，与蛋白P5相似，但显著低于体外合成的前体P5的28K（见随附论文）。根据氨基酸组成和氨基末端序列，这六种攻击素可分为两组，攻击素A - D构成碱性组，攻击素E和F构成酸性组。每组内的形式非常相似。攻击素能有效杀死大肠杆菌以及从蚕肠道分离出的另外两种革兰氏阴性菌，但对所测试的其他革兰氏阳性菌和革兰氏阴性菌不起作用。只有生长中的大肠杆菌细胞受到攻击；悬浮在磷酸盐缓冲液中的细胞没有活性。除了天蚕素和溶菌酶外，攻击素是大透目天蚕蛾体液免疫系统中的第三类抗菌蛋白。
