Berman A E, Oborotova T A, Tarasova E A, Mazurov V I
Vopr Med Khim. 1983 Mar-Apr;29(2):109-15.
Among various membrane-bound polyribosomes from chicken embryos the polyribosomes loosely bound with membranes proved to be highly active in synthesis of total proteins as well as of collagens in vitro. These data suggest that polyribosomes loosely bound with membranes were not an impurity of free polyribosomes in the total preparation of the membrane-bound polyribosomes. These polyribosomes constituted a definite class of polyribosomes active in the synthesis of secreted proteins (i.e. of collagen). In polyribosome fractions identified by their size (monosomes, light and heavy polyribosomes) all the three fractions of loosely-bound polyribosomes as well as light and heavy fractions of tightly-bound polyribosomes were active in synthesis of total proteins. Differences between tightly-and loosely-bound polyribosomes were noted also in studies of cell-free synthesis of collagen proteins. Heavy fractions of tightly-bound polyribosomes were the most active in synthesis of these proteins, light fractions were less active and monosomes did not exhibit any collagen-synthesizing activity. Only monosomes of loosely-bound polyribosomes were responsible for the synthesis of collagen. Polyribosomes loosely-bound with membranes appear to participate at early steps of membrane-polyribosome complex formation.
在鸡胚的各种膜结合多核糖体中，与膜松散结合的多核糖体在体外总蛋白以及胶原蛋白的合成中表现出高活性。这些数据表明，在膜结合多核糖体的总制备物中，与膜松散结合的多核糖体并非游离多核糖体的杂质。这些多核糖体构成了一类在分泌蛋白（即胶原蛋白）合成中具有活性的特定多核糖体。在按大小鉴定的多核糖体组分（单体、轻多核糖体和重多核糖体）中，所有三个松散结合的多核糖体组分以及紧密结合的多核糖体的轻、重组分在总蛋白合成中均具有活性。在胶原蛋白的无细胞合成研究中也注意到紧密结合和松散结合的多核糖体之间的差异。紧密结合的多核糖体的重组分在这些蛋白质的合成中最具活性，轻组分活性较低，单体则未表现出任何胶原蛋白合成活性。只有松散结合的多核糖体的单体负责胶原蛋白的合成。与膜松散结合的多核糖体似乎参与了膜 - 多核糖体复合物形成的早期步骤。
