Effect of Stearylguanidinium-Modified POPC Vesicles on the Melting Behavior of tRNA Molecules
详细信息 查看全文
- 作者：Keishi Suga ; Nozomi Watanabe ; Hiroshi Umakoshi
- 刊名：Journal of Physical Chemistry B
- 出版年：2016
- 出版时间：June 30, 2016
- 年：2016
- 卷：120
- 期：25
- 页码：5662-5669
- 全文大小：407K
- 年卷期：0
- ISSN：1520-5207
文摘
Lipid membranes interact with biomolecules via noncovalent bonding interactions, wherein the physicochemical membrane properties are key factors in the recognition and rearrangement of biomolecule conformation. In this study, vesicles were prepared using 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC) and stearylguanidinium (SG) to improve the affinity between the membrane and tRNA. Membrane fluidity decreased and dehydration of the membrane surface increased with increasing SG levels, suggesting that SG molecules could make the membrane rigid and induce a liquid-ordered (lo)-like phase. The binding constant (Ka) between nucleotide and lipid was evaluated by turbidity analysis; the Ka value for POPC/SG = (86/14) was 2.9 × 104 M–1 but was slightly decreased by vesicles in the lo-like phase. CD spectra of tRNA by the presence of POPC/SG vesicles showed C–G selective base cleavage in tRNA during heat denaturation. POPC/SG = (61/39) and POPC/SG = (40/60) effectively led to C–G base pair cleavage at the melting temperature of tRNA.