Direct Observation of Dynamic Mechanical Regulation of DNA Condensation by Environmental Stimuli
Amy Lee, Adam Karcz, Ryan Akman, Tai Zheng, Sara Kwon, Szu-Ting Chou, Sarah Sucayan, Dr. Lucas J. Tricoli, Jason M. Hustedt, Dr. Qixin Leng, Prof. Jason D. Kahn, Prof. A. James Mixson and Prof. Joonil Seog
Article first published online: 21 AUG 2014 | DOI: 10.1002/anie.201403499
Optical tweezers were used to directly measure single-molecule mechanical properties of DNA condensed using 19-mer poly-L-lysine (PLL) or branched histidine–lysine (HK) peptides. Force–extension profiles indicate that both carriers condense DNA actively. As the carrier concentration, pH, and the presence of zinc ions changes, DNA:HK complexes showed dynamically regulated mechanical properties at multiple force levels.