Wood D D
J Immunol. 1979 Nov;123(5):2395-9.
Human monocytes, when appropriately stimulated in vitro, release into the culture medium a factor (BAF) that stimulates the IgM response of T-depleted murine splenocytes to heterologous erythrocytes. The behavior of this factor on gel filtration, isoelectric focusing, ion exchange chromatography, and isopycnic centrifugation was studied. BAF appears to be a molecule of 15,000 daltons, pI 6.5, 1.33 g/ml with low solubility at low ionic strength. It is stable to acid, mild heating, and long-term storage. Activity is lost in alkali or by boiling. Papain may reduce BAF activity slightly, whereas trypsin and chymotrypsin have no significant effect. These properties are similar to those of other monokines reported to have a similar m.w.
人单核细胞在体外受到适当刺激时，会向培养基中释放一种因子（BAF），该因子可刺激去除T细胞的小鼠脾细胞对异源红细胞的IgM反应。研究了该因子在凝胶过滤、等电聚焦、离子交换色谱和等密度离心方面的行为。BAF似乎是一种分子量为15,000道尔顿、pI为6.5、密度为1.33 g/ml的分子，在低离子强度下溶解度较低。它对酸、温和加热和长期储存稳定。在碱中或煮沸会失去活性。木瓜蛋白酶可能会使BAF活性略有降低，而胰蛋白酶和糜蛋白酶则没有显著影响。这些特性与报道的其他具有相似分子量的单核因子的特性相似。
