Veenhuis M, Harder W, van Dijken J P, Mayer F
Mol Cell Biol. 1981 Oct;1(10):949-57. doi: 10.1128/mcb.1.10.949-957.1981.
The substructural organization of completely crystalline peroxisomes present in Hansenula polymorpha cells grown under methanol limitation in a chemostat was investigated by different cytochemical and ultrastructural techniques. Time-dependent cytochemical staining experiments indicated that activities of the two main constituents of these organelles, namely, alcohol oxidase and catalase, were present throughout the crystalline matrix. Catalase was completely removed from isolated peroxisomes by osmotic shock treatment. After such treatment, the ultrastructure of the crystalline matrix of the organelles remained virtually intact. Because alcohol oxidase activity was still present in this matrix, it was concluded that alcohol oxidase protein is the only structural element of the peroxisomal crystalloids. The molecular architecture of the crystalloids was investigated in ultrathin cryosections which permitted recognition of individual molecules in the crystalline matrix. Depending on the plane of sectioning, different crystalline patterns were observed. Tilting experiments indicated that these images were caused by superposition of octameric alcohol oxidase molecules arranged in a tetragonal lattice. A three-dimensional model of the crystalloid is presented. The repeating unit of this structure is composed of four alcohol oxidase molecules. The crystalloid represents an open structure, which may explain the observed free mobility of catalase molecules.
利用不同的细胞化学和超微结构技术，研究了在恒化器中甲醇受限条件下生长的多形汉逊酵母细胞中完全结晶的过氧化物酶体的亚结构组织。时间依赖性细胞化学染色实验表明，这些细胞器的两种主要成分，即乙醇氧化酶和过氧化氢酶的活性，在整个结晶基质中都存在。通过渗透休克处理，过氧化氢酶从分离的过氧化物酶体中被完全去除。经过这样的处理后，细胞器结晶基质的超微结构几乎保持完整。由于乙醇氧化酶活性仍存在于该基质中，因此得出结论，乙醇氧化酶蛋白是过氧化物酶体类晶体的唯一结构成分。在超薄冷冻切片中研究了类晶体的分子结构，这使得能够识别结晶基质中的单个分子。根据切片平面的不同，观察到了不同的结晶模式。倾斜实验表明，这些图像是由排列在四方晶格中的八聚体乙醇氧化酶分子的叠加引起的。给出了类晶体的三维模型。这种结构的重复单元由四个乙醇氧化酶分子组成。类晶体代表一种开放结构，这可能解释了观察到的过氧化氢酶分子的自由移动性。
