萱草花粉微管蛋白的生物化学性质

Biochemical Characters of Tubulin in Pollens from Day Lily

以萱草花粉为材料,采用丙酮粉法、QAE-Sephadex A50离子交换层析及FPLC技术作为主要分离纯化手段,纯化了毫克数量的萱草花粉微管蛋白,并研究了微管蛋白的生物化学及生物物理学部分性质。试验结果表明:纯化的微管蛋白在20℃时沉降系数为6.2 S;α、β2个亚基的分子量分别为56,58 kD;凝胶扫描分析纯度为93.7%;等电聚焦电泳测定等电点(PI)为5.35。光谱学性质研究表明其最大紫外吸收峰为280.8 nm;荧光光谱研究表明其最大激发波长为282 nm,此时的最大发射峰为338 nm;圆二色光谱分析二级结构是α-螺旋占27.24%、β-折叠占24.48%、无规则卷曲为48.28%,呈典型球蛋白特征。

With day lily pollen as material, by adopting acetone powder method, QAE- Sephadex A50 ion exchange chromatography and FPLC technology, we purified milligram day lily pollen tubulin and studied their biochemical characters. The results showed the tubulin has a sedimentation coefficient of 6.2 S at 20℃ and the molecular weight of α-and that of β-tubulin of pollen from day lily are 56 kD and 58 kD respectively on SDS - PAGE. The purity is 93.7% by scanning analysis. The isoelectric point is about 5.35. Further fractionation has been finished by two dimensional gel electrophoresis. The maximum ultraviolet absorption is 280.8 nm. Fluorescence emission wave length of day lily tubulin is 338nm by excitation at 282 nm. Circular dichmism （CD） spectrum analysis showed that the percentage of α-helix, β- sheet and random coil of day lily tubulin are 27.24%, 24.48% and 48.28%, respectively, indicating a typical feature of globulin.