Kitavtsev B A, Shishkin S S
Biokhimiia. 1977 Jun;42(6):1045-51.
Degradation of autolyzed (72 hrs of autolysis) and non-autolyzed RNP particles from rat skeletal muscles was studied. Distribution of the RNP particles in sucrose gradient and the amount of rRNAs present in the particles were determined. It was shown that in both cases incubation of preparations for 20 min at 60 degrees C is accompanied by an almost complete degradation of RNA extracted from the RNP particles. After 24 hour storage in a buffer, containing Mg2+ at a concentration less than 0.006 M, partial degradation of polysomes and rRNAs occurs. Incubation in the presence of 0.5 mM p-chloromercurybenzoate results in a rapid degradation of polysomes down to monosomes, whereas no additional degradation of rRNAs occurs after 24 hrs of incubation at 18 degrees C. Autolyzed RNP particles when heated up to 50-55 degrees C for 20 min, reveal a much lower stability to p-chloromercurybenzoate than do the non-autolyzed ones. Possible existence of two forms of endoribonucleases in the RNP particles from rat skeletal muscles is discussed.
研究了大鼠骨骼肌中自溶（自溶72小时）和未自溶的核糖核蛋白（RNP）颗粒的降解情况。测定了RNP颗粒在蔗糖梯度中的分布以及颗粒中存在的核糖体RNA（rRNA）的量。结果表明，在两种情况下，制剂在60℃孵育20分钟都会伴随着从RNP颗粒中提取的RNA几乎完全降解。在含有浓度低于0.006M的Mg2+的缓冲液中储存24小时后，多核糖体和rRNA会发生部分降解。在0.5mM对氯汞苯甲酸存在下孵育会导致多核糖体迅速降解为单核糖体，而在18℃孵育24小时后rRNA没有额外降解。自溶的RNP颗粒在加热至50 - 55℃ 20分钟时，与未自溶的颗粒相比，对对氯汞苯甲酸的稳定性要低得多。讨论了大鼠骨骼肌RNP颗粒中可能存在两种形式的核糖核酸内切酶。
