title: Effect of Stearylguanidinium-Modified POPC Vesicles on the Melting Behavior of tRNA Molecules.
abstract: 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 × 10(4) 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.
authors.affiliation: Division of Chemical Engineering, Graduate School of Engineering Science, Osaka University , Osaka 565-0871, Japan.
authors.forename: Keishi
authors.initials: K
authors.lastname: Suga
authors.affiliation: Division of Chemical Engineering, Graduate School of Engineering Science, Osaka University , Osaka 565-0871, Japan.
authors.forename: Nozomi
authors.initials: N
authors.lastname: Watanabe
authors.affiliation: Division of Chemical Engineering, Graduate School of Engineering Science, Osaka University , Osaka 565-0871, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Umakoshi
mesh_terms: D002942:Circular Dichroism; D019791:Guanidine / Q000737:chemistry*; D008051:Lipid Bilayers / Q000737:chemistry*; D008560:Membrane Fluidity; D009391:Nephelometry and Turbidimetry; D009690:Nucleic Acid Conformation; D009691:Nucleic Acid Denaturation; D010713:Phosphatidylcholines / Q000737:chemistry*; D012343:RNA, Transfer / Q000737:chemistry* / Q000378:metabolism; D044366:Transition Temperature
chemical_list: D008051:Lipid Bilayers; D010713:Phosphatidylcholines; D012343:RNA, Transfer; D019791:Guanidine; C028694:1-palmitoyl-2-oleoylphosphatidylcholine