褐藻裙带菜中PSII复合物及其亚复合物的分离和特性研究

Study on Isolation and Characterization of PSII Pigment-protein Complex and Subcomplexes from a Brown Alga [Undaria pinnatifida (Harvey) Suringar]

用不连续梯度蔗糖密度超离心,从经TritonX-100增溶的褐藻裙带菜类囊体膜中分离到3种色素蛋白复合物条带,分别是捕光复合物、具有光氧化活性的PSII复合物颗粒(区带II)以及PSI(区带III)。PSII颗粒经毛地黄皂苷增溶后,再次超离心分离得到3条PSII的亚复合物条带。吸收和荧光激发谱显示其中的区带II-1为墨角藻黄素-Chla/c-蛋白复合物,区带II-2为Chla/c-蛋白复合物,两者都只含20kDa多肽;而鲜绿色的区带II-3为不含捕光复合物的活性PSII核心。

Three pigment-protein complexes which were light-harvesting complex and active PSⅡ （zone Ⅱ） and PSⅠ （zone Ⅲ） particles were isolated from a brown alga Undaria pinnatifida （Harvey） Suringar by Triton X-100 sucrose gradient centrifugation. The three subcomplexes were separated by further density gradient after digitonin solubilization of PSⅡ particle. Zone Ⅱ- 1 was a fucoxanthin-Chl a/c-protein complex, and zone Ⅱ- 2 was a Chl a/c-protein complex according to their absorption and fluorescence spectra. They all presented a major peptide component at 20 kDa. The fresh green fraction zone Ⅱ-3 was a active PSⅡ core complex depleting light-harvesting complexes.