MOLECULAR AND PHYSIOLOGICAL ANALYSIS OF A THYLAKOID K+ CHANNEL PROTEIN
MOLECULAR AND PHYSIOLOGICAL ANALYSIS OF A THYLAKOID K+ CHANNEL PROTEIN
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DOI：
10.1104/pp.108.4.1725
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发表时间：
1995-08-01
期刊：
影响因子：
7.4
通讯作者：
BERKOWITZ, GA
中科院分区：
文献类型：
--
作者：
FANG, ZW;MI, F;BERKOWITZ, GA
运输研究确定了纯化的菠菜（菠菜）类囊体膜的准备K+通道蛋白。这种蛋白质从天然膜中溶解，并重建成人工脂蛋白体，保持功能完整性。一个33 kD的类囊体多肽被确定为一个假定的组成部分，这种类囊体蛋白。使用针对代表K+通道蛋白的高度保守区域的合成肽产生的抗体进行该鉴定。K+通道活性共迁移的免疫反应性33-kD多肽时，溶解的类囊体膜蛋白分级Suc密度梯度。抗体用于免疫沉淀33-kD多肽。这种类囊体膜蛋白的生理功能，阐明通过测量光合电子传递的类囊体制剂的存在和不存在的K+通道阻断剂。结果表明，K+流出类囊体腔通过这个通道蛋白是所需的光合能力的优化。这种蛋白质对光合能力的影响可能是由于K+从类囊体腔流出的电荷平衡光诱导的质子泵过这层膜的要求。
Transport studies identified a K+ channel protein in preparations of purified spinach (Spinacea oleracea) thylakoid membrane. This protein was solubilized from native membranes and reconstituted into artificial proteoliposomes with maintenance of functional integrity. A 33-kD thylakoid polypeptide was identified as a putative component of this thylakoid protein. This identification was made using an antibody raised against a synthetic peptide representing a highly conserved region of K+ channel proteins. K+ channel activity co-migrated with the immunoreactive 33-kD polypeptide when solubilized thylakoid membrane protein was fractionated on a Suc density gradient. The antibody was used to immunoprecipitate the 33-kD polypeptide. Physiological function of this thylakoid membrane protein was elucidated by measuring photosynthetic electron transport of thylakoid preparations in the presence and absence of a K+ channel blocker. Results indicated that K+ efflux from the thylakoid lumen through this channel protein is required for the optimization of photosynthetic capacity. The effect this protein has on photosynthetic capacity is likely due to the requirement for K+ efflux from the thylakoid lumen to charge-balance light-induced proton pumping across this membrane.