Kawakami M, Ihara I, Ihara S, Suzuki A, Fukui K
J Immunol. 1984 May;132(5):2578-81.
A complement-dependent bactericidal factor (RaRF) specific for the Ra chemotype strains of Salmonella and for the Ra-like strains of other enterobacteria has been found in sera of mice. We show here that the anti-Ra bactericidal factors are present in sera of all species, so far tested, of mammals, birds, reptiles, amphibians, and bony and cartilaginous fish. Certain properties, such as binding specificity, requirement of divalent cations for binding, and sensitivities to heat and reducing agents, of the factor in the representative animals were the same as or similar to those of the mouse RaRF. These results indicate that these factors have been conserved by vertebrates for more than 300 million years as a result of the necessity for the resistance to rough mutants of Gram-negative bacteria.
在小鼠血清中发现了一种对沙门氏菌Ra化学型菌株以及其他肠杆菌科Ra样菌株具有特异性的补体依赖性杀菌因子（RaRF）。我们在此表明，迄今为止所测试的所有哺乳动物、鸟类、爬行动物、两栖动物以及硬骨鱼和软骨鱼物种的血清中都存在抗Ra杀菌因子。代表性动物体内该因子的某些特性，如结合特异性、结合所需的二价阳离子、对热和还原剂的敏感性，与小鼠RaRF相同或相似。这些结果表明，由于对革兰氏阴性菌粗糙突变体产生抗性的必要性，这些因子在脊椎动物中已保存了超过3亿年。
