Takada H, Ogawa T, Yoshimura F, Otsuka K, Kokeguchi S, Kato K, Umemoto T, Kotani S
Department of Microbiology and Oral Microbiology, Osaka University Dental School, Japan.
Infect Immun. 1988 Apr;56(4):855-63. doi: 10.1128/iai.56.4.855-863.1988.
From Fusobacterium nucleatum ATCC 10953 cell envelope fraction whose inner membranes had been removed by treatment with sodium N-lauroyl sarcosinate, an outer membrane protein (37,000 Mr in a native state) was prepared by extraction with lithium dodecyl sulfate. The protein thus obtained showed distinct porin activity, namely, the ability to form hydrophilic diffusion pores by incorporation into the artificial liposome membrane. The porin fraction exhibited strong immunobiological activities in the in vitro assays: B-cell mitogenicity and polyclonal B-cell activation on murine splenocytes, stimulatory effects on guinea pig peritoneal macrophages, and enhancement of the migration of human blood monocytes. The porin fraction also exhibited immunoadjuvant activity to increase the antibody production against sheep erythrocytes in the spleen of mice that were immunized by sheep erythrocytes with porin. Although chemical analyses revealed that the test porin fraction contained a considerable amount of lipopolysaccharide (LPS) (around 12% of the fraction), the studies with LPS-nonresponding C3H/HeJ mice and on the inhibitory effects of polymyxin B strongly suggest that most of the above bioactivities are due to porin protein itself, not to coexistent LPS in the porin fraction.
从具核梭杆菌ATCC 10953的细胞包膜组分中制备一种外膜蛋白（天然状态下分子量为37,000），该细胞包膜组分的内膜已通过用N-月桂酰肌氨酸钠处理去除，方法是用十二烷基硫酸锂提取。如此获得的蛋白质表现出明显的孔蛋白活性，即通过掺入人工脂质体膜形成亲水性扩散孔的能力。该孔蛋白组分在体外试验中表现出很强的免疫生物学活性：对小鼠脾细胞具有B细胞促有丝分裂活性和多克隆B细胞激活作用，对豚鼠腹腔巨噬细胞有刺激作用，以及增强人血单核细胞的迁移。该孔蛋白组分还表现出免疫佐剂活性，可增加在用孔蛋白与绵羊红细胞免疫的小鼠脾脏中针对绵羊红细胞产生的抗体。尽管化学分析表明测试的孔蛋白组分含有相当数量的脂多糖（LPS）（约占该组分的12%），但对LPS无反应的C3H/HeJ小鼠的研究以及多粘菌素B的抑制作用强烈表明，上述大多数生物活性是由于孔蛋白本身，而不是孔蛋白组分中共存的LPS。
