Stadnichuk I N, Mineeva L A, Gusev M V
Biokhimiia. 1980 Sep;45(9):1560-7.
It was shown that phycobiliproteins are native pigment complexes, in which the protein quaternary structure is responsible for the aggregation of the chromophore groups covalently bound to the apoprotein. The main factor determining the structure of the phycobiliprotein absorption spectra is the excitone interaction of the chromophores, in which the number of bands in the spectrum is proportional to the number of interacting chromophores. In accordance with the number of bands (4) in the phycocyanobilin spectrum, i. e. chromophore of allophycocyanin and C-phycocyanin, and with the number of chromophores covalently linked to each one of the apoprotein molecules (2 for allophycocyanin and 3 for C-phycocyanin) their absorption spectra split into eight (2 X 4) and twelve (3 X 4) and twelve (3 X 4) bands, respectively. It is concluded that allophycocyanin is a native aggregate--dimer, while C-phycocyanin is a trimer of phycocyanobilin.
结果表明，藻胆蛋白是天然色素复合物，其中蛋白质四级结构负责与脱辅基蛋白共价结合的发色团基团的聚集。决定藻胆蛋白吸收光谱结构的主要因素是发色团的激子相互作用，其中光谱中的谱带数量与相互作用的发色团数量成正比。根据藻蓝胆素光谱中的谱带数量（4条），即别藻蓝蛋白和C-藻蓝蛋白的发色团，以及与每个脱辅基蛋白分子共价连接的发色团数量（别藻蓝蛋白为2个，C-藻蓝蛋白为3个），它们的吸收光谱分别分裂为8条（2×4）和12条（3×4）谱带。得出的结论是，别藻蓝蛋白是天然聚集体——二聚体，而C-藻蓝蛋白是藻蓝胆素的三聚体。
