Molecular Recognition of Nucleotides by the Guanidinium Unit at the Surface of Aqueous Micelles and Bilayers. A Comparison of Microscopic and Macroscopic Interfaces

Citations Over TimeTop 10% of 1996 papers

Abstract

Molecular recognition of the guanidinium/phosphate pair was investigated at microscopic interfaces of aqueous micelles and bilayers. Monoalkyl and dialkyl amphiphiles with guanidinium head groups were synthesized and dispersed in water to form micelles and bilayers having guanidinium groups at the aggregate surface. Binding of nucleotides such as AMP to these functionalized aggregates was evaluated by using an equilibrium dialysis (ultrafiltration) method. The observed binding constants of 102−104 M-1 are much larger than the corresponding binding constant reported for a monomerically dispersed pair in the aqueous phase (1.4 M-1) but are smaller than those found at the macroscopic air−water interface (106−107 M-1). Therefore, the macroscopic interface promotes guanidinium−phosphate interaction more effectively than the microscopic interface. The present finding indicates that the microscopic interface can strengthen hydrogen bonding and/or electrostatic interaction even in the presence of water. Saturation binding phenomena were different between micelles and bilayers. All of the guanidinium groups in fluid micelles are effective for phosphate binding, but part of the guanidinium group in bilayers are not effective probably because of steric restriction.

Related Papers

• → Interactions between Hydrophobic and Ionic Solutes in Aqueous Guanidinium Chloride and Urea Solutions: Lessons for Protein Denaturation Mechanism(2007)372 cited
• → Unfolding of Hydrophobic Polymers in Guanidinium Chloride Solutions(2010)76 cited
• → Effects of the protein denaturant guanidinium chloride on aqueous hydrophobic contact-pair interactions(2014)23 cited
• → Dissociation of hydrophobic and charged nano particles in aqueous guanidinium chloride and urea solutions: A molecular dynamics study(2011)21 cited
• → Hydrophobic Interaction Chromatography of Proteins, Nucleic Acids, Viruses, and Cells on Noncharged Amphiphilic Gels(1981)58 cited