Radiation Biology Laboratory, Smithsonian Institution, Washington, D. C. 20560.
Plant Physiol. 1969 Nov;44(11):1629-38. doi: 10.1104/pp.44.11.1629.
Phycoerythrin, a photosynthetic accessory pigment, was isolated from Porphyridium cruentum and examined by electron microscopy and disc gel electrophoresis. The absorption monomer, with maxima at 563, 545, and a shoulder at 500 nm, has a molecular weight of about 300,000. With phosphotungstic acid staining it appears as a tightly structured disc-shaped particle possessing a mean diameter of 101 +/- 0.4A and height of 54 +/- 0.7A. The absorption maxima remained the same in glutaraldehyde fixed material, and in dimer and trimer aggregates. Treatment with sodium dodecyl sulfate caused a breakdown into smaller units accompanied by a loss of the 563 nm peak. It is suggested that this absorption monomer is the in vivo functional species and comparable to the phycocyanin hexamer, but structurally distinguishable at the ultrastructural level. It has been calculated that about 35 phycobiliprotein molecules can be contained within each phycobilisome. There are 1.4 x 10(3) chlorophyll molecules per phycobilisome, but not contained within it.
藻红蛋白，一种光合辅助色素，从紫球藻中分离出来，并通过电子显微镜和盘状凝胶电泳进行了检查。吸收单体在 563、545nm 处有最大值，在 500nm 处有一个肩峰，分子量约为 300,000。用磷钨酸染色，它呈现出一种紧密结构的盘状颗粒，具有平均直径 101 +/- 0.4A 和高度 54 +/- 0.7A。戊二醛固定材料中的吸收最大值保持不变，二聚体和三聚体聚集体也是如此。用十二烷基硫酸钠处理会导致较小的单元分解，同时失去 563nm 峰。因此，该吸收单体是体内功能物种，与藻蓝蛋白六聚体相当，但在超微结构水平上具有结构可区分性。据计算，每个藻胆体可以包含约 35 个藻胆蛋白分子。每个藻胆体有 1.4 x 10(3)个叶绿素分子，但不包含在其中。
