Oborotova T A, Berman A E, Mazurov V I
Biokhimiia. 1981 Jun;46(6):1142-6.
Fractionation of polyribosomes tightly and loosely bound to the endoplasmic reticulum membranes in a sucrose density gradient was carried out. The obtained fractions (mono- and disomes, light and heavy polyribosomes) were analyzed in a homologous cell-free protein-synthesizing system in order to determine their total protein- and collagen-synthesizing activities. All the three fractions prepared by fractionation of the loosely bound polyribosomes were found to be actively involved in protein synthesis translation. In case of tightly bound polyribosomes only the fractions of light and heavy polyribosomes could actively synthesize the protein. Study of collagen synthesis in the given fractions revealed that in tightly bound polyribosomes this synthesis is localized in the light and have polyribosomal fractions, while in loosely bound ones only the fractions of mono- and disomes are responsible for active collagen synthesis. Based on the present-day concepts on the nature of bonds formed by interaction between the endoplasmic reticulum membranes and polyribosomes the polyribosomes loosely bound to the membranes cna be considered as an early step in the formation of a membrane-polyribosome complex.
在蔗糖密度梯度中对紧密结合和松散结合在内质网膜上的多核糖体进行分级分离。对获得的级分（单核糖体和双核糖体、轻多核糖体和重多核糖体）在同源无细胞蛋白质合成系统中进行分析，以确定它们总的蛋白质合成和胶原蛋白合成活性。发现通过对松散结合的多核糖体进行分级分离得到的所有三个级分都积极参与蛋白质合成翻译。对于紧密结合的多核糖体，只有轻多核糖体和重多核糖体级分能够积极合成蛋白质。对给定级分中胶原蛋白合成的研究表明，在紧密结合的多核糖体中，这种合成定位于轻多核糖体级分，而在松散结合的多核糖体中，只有单核糖体和双核糖体级分负责活跃的胶原蛋白合成。基于目前关于内质网膜与多核糖体之间相互作用形成的键的性质的概念，松散结合在膜上的多核糖体可被视为膜 - 多核糖体复合物形成的早期步骤。
