海生红藻多管藻R-藻蓝蛋白亚基组成及特性

Subunit Components and Characteristics of R-phycocyanin in Marine Red alga Polysiphonia urceolata

以海生大型红藻多管藻(Polysiphonia urceolata)为材料,经Sephadex G-150凝胶过滤和DEAE-Sepharose FF离子交换层析,从藻胆蛋白提取液中分离纯化出在非变性电泳和非变性等电聚焦中均表现单一条带的R-藻蓝蛋白(R-phycocyanin,R-PC),等电点为5.6.SDS-PAGE、变性等电聚焦及二维电泳分析表明,所得R-PC含有1种分子质量为18.2kD、pI为6.5的α亚基α16.85.2,含有分子质量为20.0kD和20.9kD、pI为5.5和5.6的4种β亚基β52.05.0、β52.05.9、β52.06.0和β250..69.该结果为深化R-PC的结构功能研究提供了有价值的实验依据.

R-phycocyanin is isolated and purified from the phycobiliprotein extract of marine red alga Polysiphonia urceolata using gel filtration through Sephadex G-150 and ion exchange chromatography on DEAE-Sepharose FF. The purified R-PC appears as a single band in native PAGE and in native isolectrie focusing （IEF） gels with pI = 5.6. Subunit analysis of the R-PC using SDS-PAGE, denaturing IEF and two-dimensional electrophoresis demon strates that the R-PC has one α subunit α65 with molecular mass of 18.2 kD and pI of 6. 5, and contains four 15 subunits with molecular mass of 20. 0 kD and 20. 9 kD and pI of 5.5 and 5.6,β5.5^20.0、β5.5^20.9、β5.6^20.0 and β5.6^20.9 These results provide valuable experimental information for improving the investigation of R-PC structure and function.