Hefti A, Ford R C, Miller M, Cox R P, Engel A
M.E. Muller Institute for High Resolution Electron Microscopy, University of Basel, Switzerland.
FEBS Lett. 1992 Jan 13;296(1):29-32. doi: 10.1016/0014-5793(92)80396-x.
Using electron microscopy of negatively stained specimens, we have investigated the shape and degree of association of photosystem (PS) I complexes in cyanobacterial thylakoid membranes. When incubated at high concentrations of magnesium chloride (greater than 0.15 M), the PSI complexes form small ordered arrays in the membrane composed of monomeric complexes in a P1 square lattice of dimensions a = b = 11 nm. Averaged projections of the complex resemble those found for the purified PSI reaction centre after reconstitution (Ford, R.C, Hefti, A. and Engel, A. (1990) EMBO J. 9, 3067-3075). Some small differences in its shape are discussed, with particular reference to the differences in the polypeptide composition of the 2 preparations. We find that the complex remains in the monomeric form in the thylakoid membrane under all the conditions tested.
利用负染标本的电子显微镜技术，我们研究了蓝藻类囊体膜中光系统（PS）I复合物的形状和缔合程度。当在高浓度氯化镁（大于0.15M）中孵育时，PSI复合物在膜中形成由单体复合物组成的小有序阵列，这些单体复合物排列在尺寸为a = b = 11nm的P1正方形晶格中。该复合物的平均投影类似于重组后纯化的PSI反应中心的投影（Ford，R.C，Hefti，A.和Engel，A.（1990）EMBO J. 9，3067 - 3075）。讨论了其形状上的一些小差异，特别提及了两种制剂多肽组成的差异。我们发现在所有测试条件下，该复合物在类囊体膜中均保持单体形式。
