Wägar G
Acta Endocrinol (Copenh). 1976 Jan;81(1):96-103.
The effect of cAMP and varying concentrations of potassium (18-72 mM) on the incorporation of L-14C-leucine into TCA-precipitable protein was studied in a cell-free system comprising rough thyroid microsomes. cAMP (2mM) alone or in combination with theopylline increased the incorporation of leucine into ribosome-bound (after DOC treatment) and extra-vesicular material, but had no significant effect on the DOC-released intravesicular material. Increase of the K+ concentration from 18 mM to 72 mM affected the incorporation of leucine into the microsomal compartments in much the same way as cAMP did. The effect of cAMP and potassium seems to be due in partly to enhanced activation of amino acids, since in a system of pH5 fraction and cell sap, both cAMP and K+ increased the incorporation of 14C-leucine into cold TCA-precipitable material. Experiments with 14C-leucyl-tRNA as a marker suggest that the effect of cAMP and K+ is a consequence not only of increased activation of amino acids, but also of increased binding of activated amino acyl-tRNA to ribosomes.
在由甲状腺粗面微粒体组成的无细胞系统中，研究了环磷酸腺苷（cAMP）和不同浓度钾离子（18 - 72 mM）对L - 14C - 亮氨酸掺入三氯乙酸（TCA）沉淀蛋白的影响。单独的cAMP（2mM）或与茶碱联合使用，均可增加亮氨酸掺入经去氧胆酸钠（DOC）处理后的核糖体结合物及囊泡外物质中，但对DOC释放的囊泡内物质无显著影响。钾离子浓度从18 mM增加到72 mM对亮氨酸掺入微粒体各部分的影响，与cAMP的影响方式大致相同。cAMP和钾离子的作用似乎部分归因于氨基酸活化的增强，因为在pH5组分和细胞液系统中，cAMP和钾离子均增加了14C - 亮氨酸掺入冷TCA沉淀物质中的量。以14C - 亮氨酰 - tRNA作为标记物的实验表明，cAMP和钾离子的作用不仅是氨基酸活化增加的结果，也是活化的氨酰 - tRNA与核糖体结合增加的结果。
