Mohapatra Anasuya, Tripathy Baishnab C
School of Life Sciences, Jawaharlal Nehru University, New Delhi, 110067, India.
Photosynth Res. 2007 Nov-Dec;94(2-3):401-10. doi: 10.1007/s11120-007-9209-6. Epub 2007 Jul 19.
Stroma, envelope and thylakoid membranes were prepared from chloroplasts isolated from leaves of Beta vulgaris. Out of total plastidic protochlorophyllide, envelope membranes contained 1.5%, thylakoids had the maximum 98.48% and stroma had a trace fraction of 0.02%. Distribution of the Mg-protoporphyrin IX and its monoester was 89.0% in thylakoids, 10.0% in stroma and 1.0% in envelope. A substantial fraction (33.77%) of plastidic protoporphyrin IX was partitioned into stroma. Envelope contained 0.66% and thylakoids had 65.57% of the total plastidic protoporphyrin IX pool. The proportion of monovinyl and divinyl forms of protochlorophyllide was almost similar in intact plastid, thylakoids, and outer and inner envelope membranes suggesting a tight regulation of vinyl reductase enzyme. The significance of differential distribution of chlorophyll biosynthetic intermediates among thylakoids, envelope and stroma is discussed.
从甜菜叶片中分离出叶绿体，制备了基质、包膜和类囊体膜。在总的质体原叶绿素酸酯中，包膜膜含有1.5%，类囊体含量最高，为98.48%，基质中仅有痕量的0.02%。镁原卟啉IX及其单酯的分布情况为：类囊体中占89.0%，基质中占10.0%，包膜中占1.0%。相当一部分（33.77%）的质体原卟啉IX分配到了基质中。包膜含有质体原卟啉IX总量的0.66%，类囊体含有65.57%。在完整质体、类囊体以及外膜和内膜中，原叶绿素酸酯的单乙烯基和二乙烯基形式的比例几乎相似，这表明乙烯还原酶受到严格调控。文中讨论了叶绿素生物合成中间体在类囊体、包膜和基质之间差异分布的意义。
