Binding of Lipids onto Polypeptides of the Thylakoid Membrane I. Galactolipids and Sulpholipid as Prosthetic Groups of Core Peptides of the Photosystem II Complex
Binding of Lipids onto Polypeptides of the Thylakoid Membrane I. Galactolipids and Sulpholipid as Prosthetic Groups of Core Peptides of the Photosystem II Complex
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脂质与类囊体膜多肽的结合 I. 半乳糖脂和硫脂作为光系统 II 复合体核心肽的辅基
DOI：
10.1515/znc-1992-0615
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发表时间：
1992
期刊：
影响因子：
--
通讯作者：
G. Schmid
中科院分区：
文献类型：
--
作者：
R. Voss;A. Radunz;G. Schmid
以野生型烟草Nicotiana tabacum var. John William 'sBroadleaf及其衍生的两个叶绿素突变体N. tabacum Su/su和N.烟草奥瑞亚通过单特异性脂质抗血清分析这些复合物的疏水肽的结合脂质分子。通过聚丙烯酰胺凝胶电泳比较三种叶绿体类型的复合物的肽组成表明，肽组成是定性相同的。一个主要的定量差异是指66 kDa的肽，这似乎是更强的凝胶中的光系统II肽来源于黄绿色和黄色烟草品种。此外，我们能够表明，不同的SDS聚丙烯酰胺凝胶电泳运行相同的PS II制剂产生的差异，在该肽的带强度。比较光密度测量表明，在这66 kDa的肽的增加总是与D1和D2肽的减少。显然，66 kDa肽是D1和D2的异二聚体。来自3种烟草的光系统II制剂的肽组成的差异首先是指分子量为28和26 kDa的捕光复合物的肽。将肽从聚丙烯酰胺凝胶转移到硝酸纤维素膜后，将其与单半乳糖脂、双半乳糖脂或硫脂的单特异性抗血清一起孵育。这些实验表明，66 kDa肽与双半乳糖脂抗体和磺脂抗体反应。在Western印迹方法中，66 kDa肽也与抗66 kDa肽的抗血清反应，所述抗66 kDa肽是先前制备和表征的，并且显示出在光系统II的反应中心区域中抑制电子传递反应。单半乳糖脂的单特异性抗血清与D1和D2肽以及与质量为42和48 kDa的叶绿素结合多肽反应，并且还与捕光复合物的26和28 kDa肽以及与表现出分子量为33、21 - 23和18 kDa的外源肽反应。而脂肪酶处理显然破坏了脂质作为硝酸纤维素膜上肽的抗原决定簇，高碘酸盐处理或用有机溶剂处理光系统II制剂不能阻止66 kDa肽与硫脂抗血清的反应。这些实验表明，由于66 kDa肽似乎是D1和D2的异二聚体，因此半乳糖脂单甘酯和双半乳糖基二甘酯以及硫脂与辅基非常相似地结合到核心肽上。
Photosystem II complexes were prepared from chloroplasts of wild type tobacco Nicotiana tabacum var. John William’s Broadleaf and from two chlorophyll mutants derived from it, namely N. tabacum Su/su and N. tabacum Su/su var. Aurea. The hydrophobic peptides of these complexes were analyzed for bound lipid molecules by means of monospecific lipid antisera. A comparison of the peptide composition of the complexes of the three chloroplast types by means of polyacrylamide gel electrophoresis showed that the peptide composition was qualitatively identical. A major quantitative difference referred to a 66 kDa peptide which appeared to be much stronger in gels of photosystem II peptides originating from the yellowgreen and the yellow tobacco variety. Furthermore, we were able to show that different SDS polyacrylamide gel electrophoresis runs of the same PS II preparation yielded differences in the band strength of this peptide. Comparative densitometric measurements showed that an increase in this 66 kDa peptide was always correlated with a decrease in the D1 and D2 peptides. Obviously, the 66 kDa peptide is the heterodimer of D1 and D2. Differences in the peptide composition of photosystem II preparations from the 3 tobacco species refer above all to peptides of the light-harvesting complex with molecular masses of 28 and 26 kDa. After the transfer of the peptides from the polyacrylamide gel to nitrocellulose membranes, they were incubated with monospecific antisera to monogalactolipid, digalactolipid or sulfolipid. These experiments showed that the 66 kDa peptide reacted with antibodies to digalactolipid and with those to sulfolipid. The 66 kDa peptide reacts in the Western blot procedure also with an antiserum to a 66 kDa peptide prepared and characterized earlier and which was shown to inhibit electron transport reactions in the region of the reaction center of photosystem II. The monospecific antiserum to monogalactolipid reacts with the D1 and D2 peptide as well as with the chlorophyll-binding polypeptides of the masses 42 and 48 kDa, and also with the 26 and 28 kDa peptides of the light-harvesting complex as well as with the extrinsic peptides exhibiting the molecular masses, 33 ,21 -23 and 18 kDa. Whereas lipase treatment apparently destroys the lipids as antigenic determinants of the peptides on the nitrocellulose membrane, periodate treatment or treatment of the photosystem II preparations with organic solvents do not prevent the reaction of the 66 kDa peptide with the sulfolipid antiserum. These experiments show as the 66 kDa peptide appears to be the heterodimer of D1 and D2, that the galactolipids mono- and digalactosyldiglyceride as well as the sulfolipid are bound, much like prosthetic groups, onto the core peptides.