Albertsson P A, Larsson C
Mol Cell Biochem. 1976 Jun 15;11(3):183-9. doi: 10.1007/BF01744998.
Chloroplasts from spinach can be separated into at least three different populations by countercurrent distribution using polymer two-phase systems. The chloroplast particles of the three populations differ in protein/chlorophyll ratio, ultrastructure and metabolism. One population, peak I, consists of intact chloroplasts surrounded by the chloroplast envelope; the second population, peak II, consists of chloroplasts, which have lost their envelopes and much of their stromal material; the third population, peak III, consists of particles containing intact chloroplasts surrounded by a membrane-bound cytoplasmic layer including mitochondria and peroxisomes. Rapid batch procedures of peak I chloroplasts incorporated 14C almost entirely into glycolate and intermediates of the Calvin cycle and starch synthesis. Only small amounts were found in sucrose and amino acids. On the other hand preparations of peak III chloroplasts have a much broader spectrum of 14C-labelled products. Sucrose, malate and some amino acids contained about 40% of the 14C incorporated. It is concluded from these experiments that sucrose is formed not within the chloroplast but in the cytoplasm from intermediates exported by the chloroplast. The origin of peak III particles and their use for studying the cooperation between the chloroplast and the surrounding cytoplasm including mitochondria and peroxisomes is discussed.
利用聚合物双相系统通过逆流分配法可将菠菜叶绿体分离成至少三种不同的群体。这三个群体的叶绿体颗粒在蛋白质/叶绿素比率、超微结构和代谢方面存在差异。一个群体，即峰I，由被叶绿体包膜包围的完整叶绿体组成；第二个群体，即峰II，由失去包膜和大部分基质物质的叶绿体组成；第三个群体，即峰III，由包含被膜结合细胞质层（包括线粒体和过氧化物酶体）包围的完整叶绿体的颗粒组成。峰I叶绿体的快速批量程序几乎将14C完全掺入乙醇酸以及卡尔文循环和淀粉合成的中间产物中。在蔗糖和氨基酸中仅发现少量。另一方面，峰III叶绿体的制剂具有更广泛的14C标记产物谱。蔗糖、苹果酸和一些氨基酸含有约40%掺入的14C。从这些实验得出的结论是，蔗糖不是在叶绿体内形成的，而是由叶绿体输出的中间产物在细胞质中形成的。讨论了峰III颗粒的起源及其在研究叶绿体与包括线粒体和过氧化物酶体在内的周围细胞质之间合作中的用途。
