Liposome-mediated conformation transition of DNA detected by molecular probe: methyl green.
Recent studies have focused on the structural features of DNA-lipid assemblies. In this paper, we take methyl green (MG) as a probe molecule to detect the conformational change of DNA molecule induced by dimethyldioctadecylammonium bromide (DDAB) liposomes before the condensation process of DNA begins. DDAB-induced DNA topology changes were investigated by cyclic voltammetry (CV), circular dichroism (CD) and UV-VIS spectrometry. We find that upon binding to DNA, positively charged liposomes induce a conformational transition of DNA molecules from the native B-form to the C motif. Conformational transition in DNA results in the binding modes of MG to DNA, changing and being isolated from DNA to the solution. More stable complexes are formed between DNA and DDAB. That is also proved by the melting study of DNA.
Huang
Weimin
W
State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, China.
Zhang
Zheling
Z
Han
Xiaojun
X
Tang
Jilin
J
Wang
Jianguo
J
Dong
Shaojun
S
Wang
Erkang
E
D000818:Animals; D002417:Cattle; D002942:Circular Dichroism; D004396:Coloring Agents / Q000737:chemistry*; D004247:DNA / Q000032:analysis / Q000737:chemistry*; D004563:Electrochemistry; D008081:Liposomes; D008739:Methyl Green / Q000737:chemistry*; D015335:Molecular Probes; D009690:Nucleic Acid Conformation; D000644:Quaternary Ammonium Compounds / Q000737:chemistry; D013056:Spectrophotometry, Ultraviolet; D013950:Thymus Gland / Q000378:metabolism
D004396:Coloring Agents; D008081:Liposomes; D015335:Molecular Probes; D000644:Quaternary Ammonium Compounds; C046112:didodecyldimethylammonium; D008739:Methyl Green; D004247:DNA