Protein synthesis has been studied in a cell-free system from chick embryo, in the presence of homologous RNA isolated from free and endoplasmic reticulum-bound polyribosomes. The two RNA fractions showed equal activities in total protein synthesis. However, while the RNA from bound polyribosomes mainly supported synthesis of high molecular weight, TCA-insoluble polypeptides, the RNA from free polyribosomes was more active in the synthesis of low molecular weight, TCA-soluble polypeptides. Optimal conditions for translation of the two RNA's under study were different when studied in a cell-free system with reduced content of endogenous matrix. Collagen synthesized in the system was identified by collagenase digestion. Collagen synthesis was demonstrated only in the presence of RNA from endoplasmic reticulum-bound polyribosomes, and represented 16-19% of total protein synthesis.

中文翻译：

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在存在从游离的和膜结合的多核糖体中分离出的鸡胚RNA的情况下，在同源，无细胞的系统中进行蛋白质生物合成。

在从游离的和内质网结合的多核糖体中分离出的同源RNA存在下，在无细胞系统中从鸡胚中研究了蛋白质合成。这两个RNA馏分在总蛋白合成中显示出相同的活性。然而，尽管来自结合的多核糖体的RNA主要支持高分子量TCA不溶性多肽的合成，但是来自游离多核糖体的RNA在低分子量TCA可溶多肽的合成中更具活性。在无细胞系统中内源性基质含量降低的情况下，研究中两种RNA的最佳翻译条件有所不同。通过胶原酶消化鉴定系统中合成的胶原。仅在存在内质网结合的多核糖体的RNA的情况下证明了胶原蛋白的合成，