원문정보
초록
영어
The mechanical nature of cation-p interactions in aqueous medium was directly measured by use of a surface forces apparatus in a model system: one surface is coated with poly-L-lysine(PLL) as cations, and the other surface is coated with three kinds of aromatic homo-polymers (poly-L-tryptophan, PTrp; poly-L-tyrosine, PTyr; polystyrene, PS) as p systems. The interaction energy between two surfaces are dependent on types of competing cations (NR4 +, NH4 +, K+, Li+, Na+), contact time, competing cation concentration, and types of aromatic side groups (indole, phenol, benzene).The adhesion to PLL in terms of strength follows the order of PTrp> PS >PTyr and the adhesion to PTrp surface follows the order ofNR4 +> NH3R+≥NH4 +»K+> Li+, Na+, qualitatively consistent with theoretical simulations. The results directly proved the theory of cation-p interactions in aqueous system and verified the hypotheses to explain the physiological phenomena (eg. potassium channel and neuroreceptor).