Rivett A J
Department of Biochemistry, University of Leicester, UK.
Enzyme Protein. 1993;47(4-6):210-9. doi: 10.1159/000468680.
Proteasomes are cylindrical particles which have a pseudohelical arrangement of subunits. On 2D-PAGE gels, rat liver proteasome preparations give rise to up to 25 proteins which are encoded by at least 16 different genes that are all members of the same family. Proteasomes are able to degrade protein substrates to acid soluble peptides. They have at least five different catalytic components which can be distinguished by the use of synthetic peptide substrates and inhibitors which have very different reactivity at the different sites. Proteasomes can undergo conformational changes when treated with various effectors of their multiple peptidase activities. They are found in the nucleus and in the cytoplasm and, in cultured cells, show changes in localization during the course of the cell cycle.
蛋白酶体是由亚基呈假螺旋排列的圆柱形颗粒。在二维聚丙烯酰胺凝胶电泳上，大鼠肝脏蛋白酶体制剂可产生多达25种蛋白质，这些蛋白质由至少16个不同的基因编码，而这些基因均为同一家族的成员。蛋白酶体能够将蛋白质底物降解为酸溶性肽。它们至少有五种不同的催化成分，可通过使用在不同位点具有非常不同反应性的合成肽底物和抑制剂来区分。当用其多种肽酶活性的各种效应物处理时，蛋白酶体可发生构象变化。它们存在于细胞核和细胞质中，在培养细胞中，在细胞周期进程中显示出定位变化。
