Hoschützky H, Nimmich W, Lottspeich F, Jann K
Max-Planck-Institut für Immunbiologie, Freiburg, F.R.G.
Microb Pathog. 1989 May;6(5):351-9. doi: 10.1016/0882-4010(89)90077-6.
The non-fimbrial adhesin NFA-4 from uropathogenic Escherichia coli O7:K98:H6 mediates the agglutination of human red cells (RBC), notably of blood group MM. The adhesin can be separated from the bacteria by heat extraction and was purified to homogeneity by ammonium sulphate precipitation and anion exchange chromatography in the presence of 8 M urea. NFA-4 consists of non-covalently linked 28 kDa subunits which tend to form aggregates of an apparent molecular weight in excess of 10(6) Da. The first 23 amino-terminal amino acids were sequenced, and no homology of this region was found with that of the blood group M specific non-fimbrial adhesin of an unrelated uropathogenic E. coli. It has, however, an about 70% homology to the corresponding region of the K88 antigen from animal-pathogenic enterotoxic E. coli. Both polyclonal and monoclonal antibodies against NFA-4 were prepared. One of the monoclonal antibodies strongly inhibits the hemagglutinating activity of both whole bacteria and purified NFA-4.
来自致病性大肠杆菌O7:K98:H6的非菌毛黏附素NFA-4介导人红细胞（RBC）的凝集，尤其是血型为MM的红细胞。该黏附素可通过热提取从细菌中分离出来，并在8M尿素存在下通过硫酸铵沉淀和阴离子交换色谱法纯化至同质。NFA-4由非共价连接的28kDa亚基组成，这些亚基倾向于形成表观分子量超过10(6)Da的聚集体。对前23个氨基末端氨基酸进行了测序，未发现该区域与无关致病性大肠杆菌的血型M特异性非菌毛黏附素的该区域具有同源性。然而，它与动物致病性肠毒素大肠杆菌的K88抗原的相应区域具有约70%的同源性。制备了针对NFA-4的多克隆抗体和单克隆抗体。其中一种单克隆抗体强烈抑制全菌和纯化的NFA-4的血凝活性。
