An adhesive protein capsule of Escherichia coli
An adhesive protein capsule of Escherichia coli
复制标题
大肠杆菌粘附蛋白胶囊
DOI：
10.1128/iai.47.1.191-200.1985
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发表时间：
1985
影响因子：
3.1
通讯作者：
F. Orskov
中科院分区：
文献类型：
--
作者：
I. Orskov;A. Birch‐Andersen;J. Duguid;J. Stenderup;F. Orskov
研究了三种先前被描述为无菌毛的血凝性大肠杆菌菌株的粘附能力的性质。从人疾病中分离的菌株粘附于人口腔和尿道上皮细胞，这种粘附不受D-甘露糖抑制。通过交叉免疫电泳，表明这三个菌株产生一种共同的抗原Z1，在37 ℃而不是18 ℃下生长后产生。其中一个菌株产生了一个额外的抗原，Z2，几乎相同的电泳迁移率在交叉免疫电泳。该菌株的一个突变体缺乏其多糖K抗原保持了粘附能力，表明K抗原不负责粘附。无囊突变体的另一个突变体产生的Z抗原量大大减少，并失去了粘附能力。Z1（和Z2？）因此认为抗原是引起粘附的原因。在十二烷基硫酸钠-聚丙烯酰胺凝胶电泳的细胞提取物的三个菌株，考马斯亮蓝染色的线被视为重，表明存在的蛋白亚基的分子量略高于14，400。用吸附的抗血清进行免疫印迹，结果表明该蛋白与交叉免疫电泳所检测到的蛋白一致。来自灰色链霉菌的蛋白酶，而不是胰蛋白酶，消化蛋白质。加热到100摄氏度并不影响它。通过免疫电子显微镜的包埋和切片的细菌，已首先处理的特异性抗血清和铁蛋白标记的抗兔免疫球蛋白，蛋白质粘附素抗体复合物被发现包围的细菌作为一个沉重的胶囊。用乙酸铀酰（pH约为4）负染色后，胶囊显示为非常细的细丝网。讨论了这种胶囊在疾病发病机制中的可能作用。
The nature of the adhesive capacity of three hemagglutinating Escherichia coli strains that had earlier been described as nonfimbriated was studied. The strains that were isolated from human disease adhered to human buccal and urinary tract epithelial cells, an adhesion that was not inhibited by D-mannose. By crossed immunoelectrophoresis it was shown that the three strains produced a common antigen, Z1, developed after growth at 37 degrees C but not 18 degrees C. One of the strains produced an additional antigen, Z2, of almost the same electrophoretic mobility in crossed immunoelectrophoresis. A mutant of this strain deficient of its polysaccharide K antigen had maintained the adhesive capacity, indicating that the K antigen was not responsible for adhesion. A further mutant of the acapsular mutant produced a strongly reduced amount of the Z antigens and had lost the ability to adhere. The Z1 (and Z2?) antigens were therefore deemed to be responsible for adhesion. In sodium dodecyl sulfate-polyacrylamide gel electrophoresis of extracts of cells of the three strains, a heavy Coomassie-blue stained line was seen, indicating the presence of a protein subunit of molecular weight slightly above 14,400. By immunoblotting with absorbed antiserum, it was shown that this protein was the same as that detected by crossed immunoelectrophoresis. Protease from Streptomyces griseus, but not trypsin, digested the protein. Heating to 100 degrees C did not affect it. By immunoelectron microscopy of embedded and sectioned bacteria that had first been treated with specific antisera and ferritin-labeled antirabbit immunoglobulin, the protein adhesin-antibody complex was found to surround the bacteria as a heavy capsule. After negative staining with uranylacetate (pH approximately 4), the capsule appeared as a mesh of very fine filaments. The possible role of this capsule in the pathogenesis of disease is discussed.