利用时间分辨冷冻透射电子显微镜观察聚（酰胺胺）树枝状大分子诱导的DNA凝聚。

Watching DNA condensation induced by poly(amido amine) dendrimers with time-resolved cryo-TEM.

作者信息

Carnerup Anna M, Ainalem Marie-Louise, Alfredsson Viveka, Nylander Tommy

机构信息

Division of Physical Chemistry, Center for Chemistry and Chemical Engineering, Lund University, P.O. Box 124, 221 00 Lund, Sweden.

出版信息

Langmuir. 2009 Nov 3;25(21):12466-70. doi: 10.1021/la903068v.

DOI:10.1021/la903068v

PMID:19856988

Abstract

The condensation of DNA by poly(amido amine) dendrimers of generation 1, 2, and 4 has been followed by time-resolved cryogenic transmission electron microscopy (cryo-TEM). The recorded images show that significant morphological rearrangement occurs for DNA condensed with the lower generation dendrimers leading to the formation of toroidal aggregates. Higher charge density dendrimers, on the other hand, give rise to globular aggregates, where no transient morphologies are observed. We suggest that the dendrimers in this case are kinetically trapped as soon as they bind to the DNA strand.

摘要

利用时间分辨低温透射电子显微镜（cryo-TEM）对第1代、第2代和第4代聚（酰胺胺）树枝状大分子介导的DNA凝聚过程进行了跟踪研究。记录的图像显示，较低代数树枝状大分子凝聚的DNA会发生显著的形态重排，形成环形聚集体。另一方面，电荷密度较高的树枝状大分子则会产生球状聚集体，在其中未观察到瞬态形态。我们认为，在这种情况下，树枝状大分子一旦与DNA链结合就会在动力学上被捕获。