Processing of a wheat light-harvesting chlorophyll a/b protein precursor by a soluble enzyme from higher plant chloroplasts.
Processing of a wheat light-harvesting chlorophyll a/b protein precursor by a soluble enzyme from higher plant chloroplasts.
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通过较高植物叶绿体的可溶性酶来处理小麦轻融合叶绿素A/B蛋白的前体。
DOI：
10.1083/jcb.105.6.2641
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发表时间：
1987-12
影响因子：
7.8
通讯作者：
Abad, M S
中科院分区：
文献类型：
--
作者：
Lamppa, G K;Abad, M S
已经在高等植物叶绿体中鉴定了切割捕光叶绿素a/B结合蛋白（LHCP）的前体的加工活性。先前表征的小麦LHCP基因（Lamppa，G.K.，G. Morelli和N.- H. Chua，1985年。摩尔Cell Biol.5：1370- 1378）用于合成RNA，随后在体外合成标记的前体多肽。孵育的LHCP前体与溶解的叶绿体的可溶性提取物，去除类囊体和膜囊泡后，导致在一个单一的25 kD肽的释放。与此相反，当LHCP前体用于与完整的豌豆或小麦叶绿体的输入反应时，发现两种形式（25和26 kD）的成熟LHCP。加工活性的性质表明它是一种内肽酶。豌豆和小麦这两种不同的高等植物的叶绿体都含有加工酶，表明其在LHCP组装成类囊体中的生理重要性。我们讨论了LHCP前体加工的可溶性酶，可能是在基质室的影响。
A processing activity has been identified in higher plant chloroplasts that cleaves the precursor of the light-harvesting chlorophyll a/b- binding protein (LHCP). A wheat LHCP gene previously characterized (Lamppa, G.K., G. Morelli, and N.-H. Chua, 1985. Mol. Cell Biol. 5:1370- 1378) was used to synthesize RNA and subsequently the labeled precursor polypeptide in vitro. Incubation of the LHCP precursors with a soluble extract from lysed chloroplasts, after removal of the thylakoids and membrane vesicles, resulted in the release of a single 25-kD peptide. In contrast, when the LHCP precursors were used in an import reaction with intact pea or wheat chloroplasts, two forms (25 and 26 kD) of mature LHCP were found. The peptide released by the processing activity in the organelle-free assay comigrated with the lower molecular mass form of mature LHCP produced during import. Properties of the processing activity suggest that it is an endopeptidase. Chloroplasts from both pea and wheat, two divergent higher plants, contain the processing enzyme, suggesting its physiological importance in LHCP assembly into the thylakoids. We discuss the implications of LHCP precursor processing by a soluble enzyme that may be in the stromal compartment.