Gonzales L W, Geel S E
J Neurosci Res. 1976;2(5-6):373-84. doi: 10.1002/jnr.490020505.
A time-decay colchicine-binding assay was used under optimal conditions for measuring tubulin concentration in the cerebral cortex and cerebellum during postnatal development. In both brain areas soluble tubulin concentration (pmoles colchicine bound/mg tissue) declined by about 35% between 4 and 12 days of age after which the decrease was more gradual up to adulthood. Colchicine-binding protein concentration of particulate fractions, on the other hand, increased between 4 and 12 days of age followed by relatively little change. The concentration of tubulin in the soluble and particulate fractions of the cerebral cortex was 45% and 75% greater, respectively, than corresponding fractions of the cerebellum. The expression of tubulin on the basis of DNA, revealed marked regional differences which can be considered a reflection of differences in the relative extent of morphological differentiation in these areas during the postnatal period. Tubulin in both soluble and particulate fractions exhibited a marked increase in lability for colchicine binding from approximately 12 days of age. The half-life for loss of colchicine-binding activity was 2,5-fold greater in particulate compared to soluble fractions. An analysis of the characteristics of the particulate colchicine-binding reaction provides additional support for the hypothesis that it represents a functionally significant association of tubulin with the membranous components.
在产后发育过程中，采用时间衰减秋水仙碱结合试验在最佳条件下测量大脑皮层和小脑微管蛋白的浓度。在这两个脑区，可溶性微管蛋白浓度（每毫克组织结合的秋水仙碱皮摩尔数）在4至12日龄之间下降了约35%，此后下降更为缓慢，直至成年。另一方面，颗粒部分的秋水仙碱结合蛋白浓度在4至12日龄之间增加，随后变化相对较小。大脑皮层可溶性和颗粒部分的微管蛋白浓度分别比小脑相应部分高45%和75%。基于DNA的微管蛋白表达显示出明显的区域差异，这可被视为产后时期这些区域形态分化相对程度差异的反映。可溶性和颗粒部分的微管蛋白从大约12日龄开始对秋水仙碱结合的不稳定性显著增加。颗粒部分秋水仙碱结合活性丧失的半衰期比可溶性部分大2.5倍。对颗粒秋水仙碱结合反应特征的分析为以下假设提供了额外支持，即它代表微管蛋白与膜成分的功能上重要的结合。
