Effect of headgroup on DNA-cationic surfactant interactions.
The interaction behavior of DNA with different types of hydroxylated cationic surfactants has been studied. Attention was directed to how the introduction of hydroxyl substituents at the headgroup of the cationic surfactants affects the compaction of DNA. The DNA-cationic surfactant interaction was investigated at different charge ratios by several methods like UV melting, ethidium bromide exclusion, and gel electrophoresis. Studies show that there is a discrete transition in the DNA chain from extended coils (free chain) to a compact form and that this transition does not depend substantially on the architecture of the headgroup. However, the accessibility of DNA to ethidium bromide is preserved to a significantly larger extent for the more hydrophilic surfactants. This was discussed in terms of surfactant packing. Observations are interpreted to reflect that the surfactants with more substituents have a larger headgroup and therefore form smaller micellar aggregates; these higher curvature aggregates lead to a less efficient, "patch-like" coverage of DNA. The more hydrophilic surfactants also presented a significantly lower cytotoxicity, which is important for biotechnological applications.
Dasgupta
Antara
A
Department of Biological Chemistry, Centre for Advanced Materials, Indian Association for the Cultivation of Science, Jadavpur, Kolkata 700032, India.
Das
Prasanta Kumar
PK
Dias
Rita S
RS
Miguel
Maria G
MG
Lindman
Björn
B
Jadhav
Vaibhav M
VM
Gnanamani
Muthaiah
M
Maiti
Souvik
S
D000818:Animals; D002412:Cations / Q000737:chemistry; D002417:Cattle; D002470:Cell Survival / Q000187:drug effects; D004247:DNA / Q000737:chemistry*; D004586:Electrophoresis; D004996:Ethidium / Q000737:chemistry; D013501:Surface-Active Agents / Q000737:chemistry* / Q000633:toxicity; D014466:Ultraviolet Rays
D002412:Cations; D013501:Surface-Active Agents; D004247:DNA; D004996:Ethidium