Hamuro J, Hadding U, Bitter-Suermann D
J Immunol. 1978 Feb;120(2):438-44.
Functionally active guinea pig factor B was purified by a combination of chromatographic steps including Sephadex G-25, QAE A25, QAE A50, CM C50, and Sepharose 4B coupled with purified cobra venom factor. Purified factor B had a m.w. of 106,000 daltons and a single subunit structure. It was heat labile. After cleavage of native B with cobra venom factor coupled to Sepharose 4B in the presence of D, the resulting two fragments, the larger one (Bb) and the smaller one (Ba), were further purified. The m.w. of Bb and Ba was determined as 64,000 and 53,000 daltons, respectively, by SDS-PAGE. Neither of the fragments evoked a contraction of guinea pig ileum or histamine release from rat mast cells. Only the smaller fragment Ba (at a concentration of 120 nM) stimulated guinea pig peritoneal polymorphonuclear leukocytes to respond with increased movement. This activity as well as the antigenicity of Ba were heat stable, but were sensitive to trypsin digestion, whereas the antigenicity of Bb was heat labile.
通过包括葡聚糖凝胶G - 25、季铵乙基纤维素A25、季铵乙基纤维素A50、羧甲基纤维素C50和与纯化的眼镜蛇毒因子偶联的琼脂糖4B在内的一系列色谱步骤，纯化了具有功能活性的豚鼠B因子。纯化后的B因子分子量为106,000道尔顿，具有单一亚基结构。它对热不稳定。在D存在下，用与琼脂糖4B偶联的眼镜蛇毒因子切割天然B因子后，得到的两个片段，较大的片段（Bb）和较小的片段（Ba），被进一步纯化。通过SDS - PAGE测定，Bb和Ba的分子量分别为64,000和53,000道尔顿。这两个片段均未引起豚鼠回肠收缩或大鼠肥大细胞释放组胺。只有较小的片段Ba（浓度为120 nM）刺激豚鼠腹腔多形核白细胞增加运动反应。Ba的这种活性以及抗原性对热稳定，但对胰蛋白酶消化敏感，而Bb的抗原性对热不稳定。
