条斑紫菜藻胆蛋白性质的研究Ⅲ.不同环境条件下R-藻红蛋白吸收光谱类型的转变

STUDY OF PHYCOBILIPROTEINS IN PORPHYRA YEZOENSIS Ⅲ. THE TRANSFORMATION OF ABSORPTION SPECTRA TYPE IN R-PHYCOERYTHRIN UNDER THE CONDITION OF DIFFERENT ENVIRONMENTS

条斑紫菜的R-藻红蛋白在pH:5.8—8.4的几种缓冲液中保存,经过大约4个星期,其吸收光谱由原有的双峰型转变为三峰型;在pH=8.4的聚丙烯酰胺梯度凝胶电泳后或在微量四甲基乙二胺作用下发生了同样的变化。但在变性剂SDS或尿素存在下,吸收光谱中540nm和565nm的峰强度比逐渐改变,直至565nm吸收峰消失,始终没有从双峰型转变为三峰型的迹象。显然,条斑紫菜R-藻红蛋白吸收光谱类型的转变不是变性引起的。

During the storage period of the R-phycoerythrin from Porphyra yezoensis in various buffer solutions at pH 5.8-8.4, the absorption spectra lost the original characteristic diade type at the very beginning and changed to triade type after an elapse of about four weeks. After the polyacrylamide gradient gel electrophoresis at pH 8.4 or under the action of trace amount of tetramethylethylenediamine, the same change of types took place. However, in the presence of the denaturing agent SDS or urea by varying the concentrations of the denaturing agent, the ratio of the strengths of the peaks 540nm and 565nm in the absorption spectra gradually un-derwent alternation until the disappearance of the 565nm peak, there was no indication at all about the transformation from diade to triade type. If is apparent that the changes of types of the absorption spectrum of R-phycoerythrin from Porphyra yezoensis in comparison with the results obtained from the action of denaturing agent are of different mechanisms, in other words, the change from diade to triade is not due to denaturation.An explanation for the cause of the transformation from diade to triade will be given when more experimental facts are obtained.