发育中大鼠脑制备物中与氨基酸掺入相关的微粒体成分

Microsomal components in relation to amino acid incorporation by preparations from the developing rat brain.

Lim L, Adams D H

Biochem J. 1967 Jul;104(1):229-38. doi: 10.1042/bj1040229.

Abstract

After incorporation of [(14)C]valine in vitro, cerebral microsomes were separated into membrane-bound and free ribosomes by sucrose-density-gradient centrifugation. 2. In preparations from both 4-day-old and adult rats, free and bound ribosomes incorporated [(14)C]valine. Free ribosomes could be found as polysomes, which were highly active. 3. Microsomes labelled with [(14)C]valine in vitro were fractionated after deoxycholate treatment into a preliminary sediment, sedimented at 105000g (5min.), and ribonucleoprotein particles, sedimented at 150000g (70min.), to determine the role of membrane-bound ribosomes. In the adult the ribonucleoprotein particles retained most of the radioactivity, whereas in the young the preliminary sediment was as highly labelled as the ribonucleoprotein particles. 4. The labelled preliminary sediment from young preparations was both ribonuclease- and deoxycholate-resistant, and the nature of this material is discussed in terms of a possible structural component of microsomal membranes.

摘要

在体外将[(14)C]缬氨酸掺入后，通过蔗糖密度梯度离心将脑微粒体分离为膜结合核糖体和游离核糖体。2. 在4日龄大鼠和成年大鼠的制备物中，游离核糖体和结合核糖体都掺入了[(14)C]缬氨酸。游离核糖体可以以多核糖体的形式存在，其活性很高。3. 体外用[(14)C]缬氨酸标记的微粒体在脱氧胆酸盐处理后被分离成一个初步沉淀物（在105000g下沉淀5分钟）和核糖核蛋白颗粒（在150000g下沉淀70分钟），以确定膜结合核糖体的作用。在成年大鼠中，核糖核蛋白颗粒保留了大部分放射性，而在幼鼠中，初步沉淀物的放射性与核糖核蛋白颗粒一样高。4. 来自幼鼠制备物的标记初步沉淀物对核糖核酸酶和脱氧胆酸盐都有抗性，并且根据微粒体膜可能的结构成分对这种物质的性质进行了讨论。