羽藻叶绿体膜的纯化与多肽的初步研究

STUDY ON THE PURIFICATION OF THE MEMBRANE AND THE POLYPEPTIDE OF CHLOROPLAST MEMBRANE FROM BRYOPSIS CORTICULANS

细胞膜系统,是细胞许多生命现象如收缩运动、信息传递、物质运输等的场所和调节关键部位。七十年代首先在红细胞发现了膜骨架。八十年代大多数红细胞膜蛋白已经提纯,其功能亦已清楚。在植物中,Palevitz等(1974年)

Thylakoids and intact chloroplasts, as well as chloroplast membrane of Bryopsis corticu-lans collected from Huiquan Bay of Qingdao in 1988 were purified by discontinuous sucrose density gradient centrifugation. The intactness of chloroplasts was measured by a oxygen electrode. About 86% of chloroplasts were intact in the obtained chloroplast preparation. The activities of cytochrome oxidase and catalase in the purified chloroplasts showed that there were slightly contamination caused by mitochondria and peroxisomes in this purified chloroplasts. The purity fulfiled the requirement for the study of polypeptides of chloroplast membranes.The polypeptides of chloroplast membranes from Bryopsis coniculans and spinach (Spina-cia oleracea L.) were compared by SDS-PAGE.The 45 KD (MW of actin) protein bands were found in the intact chloroplast membrane of spinach and Bryopsis coniculans, but not in the two thylakoids. The 240 KD and 220 KD (MW of the α band and β band of spectrin) bands were obvious in the intact chloroplast membrane of Bryopsis coniculans, but only weaker 240 KD protein band in the chloroplast membrane of spinach. There were no 240 KD and 220 KD polypeptides bands in the two thylakoids.It seems likely that the main proteins of membrane skeleton may be in envelope of chloroplast. These results will be further confirmed by immunotechnique.