Schultz P, Weiss E, Colin P, Régnier E, Oudet P
Chromosoma. 1986;94(3):189-98. doi: 10.1007/BF00288493.
Direct mass determination of purified SV40 minichromosomes was obtained by scanning transmission electron microscopy. Twenty to thirty percent of the minichromosomes were found with an Mr of 6.9 +/- 0.4 X 10(6). The rest of the molecules formed a spread Mr distribution ranging from 7.3 X 10(6) to 9.5 X 10(6) due possibly to different contents of the virus-coded proteins, mainly VP1. The apparent mass histogram of individual SV40 nucleosomes presents three maxima at Mr 2.1 X 10(5), 2.6 X 10(5) and 3.1 X 10(5) that could correspond to partially unravelled nucleosomes, complete nucleosomes and complete nucleosomes with the addition of VP1. Beaded structures with a higher mass were also measured; some were found at either side of the open nucleosome-free region.
通过扫描透射电子显微镜对纯化的SV40微型染色体进行直接质量测定。发现20%至30%的微型染色体的分子量为6.9±0.4×10⁶。其余分子形成了一个分子量分布范围从7.3×10⁶到9.5×10⁶的分布图谱，这可能是由于病毒编码蛋白（主要是VP1）的含量不同所致。单个SV40核小体的表观质量直方图在分子量2.1×10⁵、2.6×10⁵和3.1×10⁵处呈现三个最大值，这可能分别对应部分解开的核小体、完整的核小体以及添加了VP1的完整核小体。还测量了质量更高的串珠状结构；在无核小体的开放区域两侧发现了一些此类结构。
