Chaturvedi M M, Kanungo M S
Biochem Int. 1983 Mar;6(3):357-63.
Micrococcal nuclease (MCN) and DNase I were used to study the conformational changes in chromatin of the brain of rats of different ages. Purified nuclei and chromatin were digested separately by MCN and DNase I. Kinetics of digestion of chromatin by MCN are similar for young, adult and old rats. Also agarose gel electrophoresis of DNA fragments do not show any differences. The kinetics of digestion with DNase I, on the other hand, are greater and faster for 20-week old rats than for 90-week old rats. High performance denaturing polyacrylamide gel electrophoresis reveals that a greater amount of smaller fragments of DNA are produced in the 20-week old rats than in the 90-week. These conformational changes occur in the chromatin during aging.
使用微球菌核酸酶（MCN）和脱氧核糖核酸酶I（DNase I）研究不同年龄大鼠大脑染色质的构象变化。纯化的细胞核和染色质分别用MCN和DNase I进行消化。MCN对年轻、成年和老年大鼠染色质的消化动力学相似。此外，DNA片段的琼脂糖凝胶电泳未显示任何差异。另一方面，DNase I对20周龄大鼠的消化动力学比对90周龄大鼠的更大且更快。高效变性聚丙烯酰胺凝胶电泳显示，20周龄大鼠产生的较小DNA片段比90周龄大鼠的更多。这些构象变化在衰老过程中发生在染色质中。
