THYLAKOID MEMBRANE POLYPEPTIDES OF CHLAMYDOMONAS-REINHARDTII - WILD-TYPE AND MUTANT STRAINS DEFICIENT IN PHOTOSYSTEM 2 REACTION CENTER
THYLAKOID MEMBRANE POLYPEPTIDES OF CHLAMYDOMONAS-REINHARDTII - WILD-TYPE AND MUTANT STRAINS DEFICIENT IN PHOTOSYSTEM 2 REACTION CENTER
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DOI：
10.1073/pnas.72.6.2175
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发表时间：
1975-01-01
影响因子：
11.1
通讯作者：
BENNOUN, P
中科院分区：
文献类型：
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作者：
CHUA, NH;BENNOUN, P
通过在含有5 mM HEPES（N-2-羟乙基哌嗪-N-2-乙磺酸）-10mM EDTA（pH 7.5）的1.8M蔗糖层中浮选，从莱茵衣藻的匀浆中获得未堆叠的类囊体膜囊泡。十二烷基硫酸钠梯度凝胶电泳显示，野生型膜具有总共至少33种多肽，分子量范围从68，000到小于10，000。野生型和三个非光合突变株进行了研究，就其光合电子传递特性，荧光上升动力学，和他们的膜多肽组合物。结果表明，膜多肽（分子量= 47，000）的存在与光系统II反应中心的活性之间存在强相关性。这种多肽从F34（缺少光系统II的主要电子受体Q的孟德尔突变体）中缺失，但在F34的抑制菌株中部分恢复，其中存在光系统II活性的不完全恢复。在温度敏感突变体T4中，相同的多肽仅在35度生长的细胞中以减少的量存在，而在25度生长的细胞中不存在。从荧光上升动力学和部分光化学反应的证据表明，在25 ℃下生长的细胞与野生型细胞相似，但在35 ℃下生长的细胞严重缺乏Q。
Unstacked thylakoid membrane vesicles were obtained from a homogenate of Chlamydomonas reinhardtii by flotation in a 1.8 M sucrose layer containing 5 mM HEPES (N-2-hydroxyethylpiperazine-N-2-ethanesulfonic acid)-10 mM EDTA (pH 7.5). Sodium dodecyl sulfate-gradient gel electrophoresis showed that the wildtype membranes have a total of at least 33 polypeptides ranging in molecular weights from 68,000 to less than 10,000. The wild-type and three non-photosynthetic mutant strains were studied with respect to their photosynthetic electron transport properties, their fluorescence rise kinetics, and their membrane polypeptide compositions. The results showed a strong correlation between the presence of a membrane polypeptide (molecular weight = 47,000) and the activity of the photosystem II reaction center. This polypeptide is missing from F34 (a mendelian mutant lacking Q, the primary electron acceptor of photosystem II), but is partially restored in a suppressed strain of F34 in which there is an incomplete recovery of photosystem II activity. In a thermosensitive mutant, T4, the same polypeptide is present in reduced amount only in cells grown at 35 degrees but not in those grown at 25 degrees. Evidence from fluorescence rise kinetics and partial photochemical reactions show that the cells grown at 25 degree are similar to wild-type cells but the cells grown at 35 degrees are greatly deficient in Q.