Baumeister W, Dahlmann B, Hegerl R, Kopp F, Kuehn L, Pfeifer G
Max-Planck-Institut für Biochemie, Martinsried, FRG.
FEBS Lett. 1988 Dec 5;241(1-2):239-45. doi: 10.1016/0014-5793(88)81069-x.
One electron micrographs, negatively stained multicatalytic proteinase molecules are viewed end-on (ring shaped) or side-on (rectangular shaped). For aurothioglucose, ammonium molybdate- and phosphotungstate-stained molecules, the dimensions measured are consistent. In contrast, uranyl acetate-staining reveals ring-shaped particles which vary in diameter between 12 and 16 nm. This is due to a partial collapse and substantial flattening of the structure. Digital image analysis of side-on views of the particles reveals a tripartite, reel-shaped structure. Within the ring-like, end-on projections of ammonium molybdate-stained molecules six local centres of mass can be discerned; their position appears to depart, however, from a true six-fold symmetry.
在电子显微镜照片中，经负染的多催化蛋白酶分子呈端视（环形）或侧视（矩形）。对于经金硫葡萄糖、钼酸铵和磷钨酸盐染色的分子，所测量的尺寸是一致的。相比之下，醋酸铀染色显示直径在12至16纳米之间变化的环形颗粒。这是由于结构的部分塌陷和大量扁平化所致。对颗粒侧视图的数字图像分析揭示了一种三方的、卷轴状结构。在钼酸铵染色分子的环状端视投影内，可以辨别出六个局部质心；然而，它们的位置似乎偏离了真正的六重对称性。
