Heterogeneous Cationic Liposomes Modified with 3β-{N-[(N′,N′-Dimethylamino)ethyl]carbamoyl}cholesterol Can Induce Partial Conformational Changes in Messenger RNA and Regulate Translation in an Escherichia coli Cell-Free Translation System

July 28, 2017

Title

Heterogeneous Cationic Liposomes Modified with 3β-{N-[(N′,N′-Dimethylamino)ethyl]carbamoyl}cholesterol Can Induce Partial Conformational Changes in Messenger RNA and Regulate Translation in an Escherichia coli Cell-Free Translation System

Author

Keishi Suga, Tomoyuki Tanabe, Hiroshi Umakoshi

Year

2013

Journal

Langmuir

Abstract

The effect of cationic liposomes (CLs) on messenger RNA(mRNA) conformation and translation was studied, focusing on membrane heterogeneity. CLs, composed of 1,2-dioleoyl-sn-glycerol-3-phosphocholine/1,2-dioleoyl-3-timethylammonium propane (DOPC/DOTAP) and DOPC/3β-{N-[(N′,N′-dimethylamino)ethyl]carbamoyl}cholesterol (DOPC/DC-Ch), inhibited mRNA translation in an Escherichia coli cell-free translation system. Analysis of the membrane fluidity and polarity indicated a heterogeneous DOPC/DC-Ch (70/30) membrane, while other CLs exhibited homogeneous disordered membranes. mRNA adsorbed onto DOPC/DC-Ch liposomes showed translational activity, while DOPC/DOTAP liposomes inhibited mRNA translation in proportion to its adsorption onto membranes. Dehydration of DOPC/DOTAP (70/30) and DOPC/DC-Ch (70/30) was observed in the presence of mRNA but not in the case of zwitterionic DOPC liposomes, indicating that mRNA binds in regions between the phosphate [-PO2–-] and carbonyl [-C=O-] moieties of lipids. UV resonance Raman spectroscopy suggests that adenine, cytosine, and guanine interact with DOPC/DOTAP (70/30) and DOPC/DC-Ch (70/30) but not with DOPC. Circular dichroism indicates that DOPC/DOTAP (70/30) extensively denatured the mRNA. In contrast, heterogeneous DOPC/DC-Ch (70/30) induced partial conformational changes but maintained the translational activity of mRNA.

Instrument

J-820

Keywords

Circular dichroism, RNA structure, Vesicle interactions, Biochemistry