Alscher R, Patterson R, Jagendorf A T
Division of Biological Sciences, Cornell University, Ithaca, New York 14853.
Plant Physiol. 1978 Jul;62(1):88-93. doi: 10.1104/pp.62.1.88.
Pea (Pisum sativum) chloroplast thylakoid membranes were prepared by washing in hypotonic buffers. These membranes contained bound ribosomes which were active in protein synthesis when supplemented with soluble components from a strain of Escherichia coli low in ribonuclease. After dissolving the membranes by Triton and purification of the ribosomes, sucrose density gradient profiles indicated the presence of polysomal material as well as monomeric ribosomes. Most of the products of protein synthesis remained associated with the thylakoid membranes even after ribosomes were removed completely by high salt concentrations in the absence of Mg(2+). Of the newly formed products, 50% could be digested by pronase, while the remainder were protected by their association with the thylakoid membranes. The products are likely to be a mixture of intrinsic and extrinsic membrane proteins, with only the former completely protected by the membranes from attack by proteases.
豌豆（Pisum sativum）叶绿体类囊体膜通过在低渗缓冲液中洗涤制备。这些膜含有结合核糖体，当补充来自核糖核酸酶含量低的大肠杆菌菌株的可溶性成分时，它们在蛋白质合成中具有活性。用 Triton 溶解膜并纯化核糖体后，蔗糖密度梯度图谱表明存在多聚核糖体物质以及单体核糖体。即使在不存在 Mg(2+) 的情况下通过高盐浓度完全去除核糖体后，大部分蛋白质合成产物仍与类囊体膜结合。在新形成的产物中，50% 可被链霉蛋白酶消化，而其余部分则因与类囊体膜结合而受到保护。这些产物可能是内在膜蛋白和外在膜蛋白的混合物，只有前者完全受到膜的保护，免受蛋白酶的攻击。
