Biochemical and physicochemical characterization of mouse B cell growth factor: a lymphokine distinct from interleukin 2.
Biochemical and physicochemical characterization of mouse B cell growth factor: a lymphokine distinct from interleukin 2.
复制标题
小鼠 B 细胞生长因子的生化和物理化学特征：一种不同于白细胞介素 2 的淋巴因子。
作者：
J. Farrar;M. Howard;J. Fuller;W. Paul
C57BL/6 小鼠 EL-4 胸腺瘤的一个亚系在佛波醇肉豆蔻酸酯乙酸酯 (PMA) 刺激下产生 B 细胞生长因子 (BCGF)，共同刺激抗 IgM 刺激的脾 B 细胞。根据多种色谱标准，EL-4 胸腺瘤培养物上清液中存在的 BCGF 与 IL 2 不同。未处理的BCGF表现出等电点的异质性(pH 6.4至6.6、7.4至7.6、8.5至8.7)，所有这些均比IL 2的等电点(pH 3.5至4.8)更碱性。神经氨酸酶处理的 BCGF 表现出 9.3 的单一主要 pl，这也不同于类似处理的 IL 2。此外，IL 2 和 BCGF 表现出不同的单体分子量。在非还原条件下通过 SDS 凝胶电泳（IL 2 为 21,000；BCGF 为 11,000 和 15,000）。 IL 2 的生物活性与 BCGF 活性一样对胰蛋白酶失活敏感。因此，BCGF和IL 2似乎是生物学和生化上不同的糖蛋白。
A subline of the C57BL/6 mouse EL-4 thymoma produces upon stimulation with phorbol myristate acetate (PMA) a B cell growth factor (BCGF) that co-stimulates anti-IgM-stimulated splenic B cells. The BCGF present in the EL-4 thymoma culture supernatants is shown to be distinct from IL 2 by a variety of chromatographic criteria. Untreated BCGF exhibits a heterogeneity of isoelectric points (pH 6.4 to 6.6, 7.4 to 7.6, 8.5 to 8.7) all of which are more alkaline than that of IL 2 (pl 3.5 to 4.8). Neuraminidase-treated BCGF exhibits a single major pl of 9.3 that is also distinct from similarly treated IL 2. Moreover, IL 2 and BCGF exhibit distinct monomeric m.w. by SDS gel electrophoresis under nonreducing conditions (IL 2 is 21,000; BCGF is 11,000 and 15,000). The biologic activity of IL 2 is sensitive to trypsin inactivation as is BCGF activity. Thus, BCGF and IL 2 appear to be biologically and biochemically distinct glycoproteins.