Beltramo D M, Nuñez M, Alonso A D, Barra H S
Centro de Investigaciones en Quimica Biológica de Córdoba (CIQUIBIC), Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Argentina.
Mol Cell Biochem. 1994 Dec 7;141(1):57-63. doi: 10.1007/BF00935591.
Brain membrane preparations contain tubulin that can be extracted with Triton X-114. After the extract is allowed to partition, 8% of the total brain tubulin is isolated as a hydrophobic compound in the detergent-rich phase. Cytosolic tubulin does not show this hydrophobic behaviour since it is recovered in the aqueous phase. Membrane tubulin can be released by 0.1 M Na2 CO3 treatment at pH > or = 11.5 in such a way that the hydrophobic tubulin is converted into the hydrophilic form. These results suggest that tubulin exists associated with some membrane component that confers the hydrophobic behaviour to tubulin. If the tissue is homogenized in microtubule-stabilizing buffer containing Triton X-100, the hydrophobic tubulin is isolated from the microtubule fraction. This result indicates that the hydrophobic tubulin isolated from membrane preparations belongs to microtubules that in vivo are associated to membranes. Therefore, hydrophobic tubulin (tubulin-membrane component complex) can be obtained from membranes or from microtubules depending on the conditions of brain homogenization.
脑膜制剂中含有可被 Triton X - 114 提取的微管蛋白。提取物进行分配后，总脑微管蛋白的 8% 以疏水化合物的形式分离在富含去污剂的相中。胞质微管蛋白不表现出这种疏水行为，因为它在水相中被回收。膜微管蛋白可通过在 pH≥11.5 的条件下用 0.1 M Na2CO3 处理而释放，使得疏水微管蛋白转化为亲水形式。这些结果表明，微管蛋白与某些赋予其疏水行为的膜成分相关联存在。如果在含有 Triton X - 100 的微管稳定缓冲液中对组织进行匀浆，疏水微管蛋白会从微管部分分离出来。这一结果表明，从膜制剂中分离出的疏水微管蛋白属于在体内与膜相关联的微管。因此，根据脑匀浆的条件，疏水微管蛋白（微管蛋白 - 膜成分复合物）可从膜或微管中获得。
