Initial experiments of a technique for detecting the strength of certain ion-electron interactions in water yielded unexpected results. When it comes to power, the interactions between positively charged ions (cations) and negatively charged pi(π)-electrons are considered to be the most important influence. Such interactions are common in biological systems and are involved in a variety of water-based activities, including protein folding, molecular recognition, and ion transport. However, researchers have had difficulty studying cation-pi(π) interactions in such aqueous environments. A group of scientists from China has developed a technique that allows to study how water molecules affect the strength of cation-pi(π) interactions.
According to the team, this approach could be modified to measure the strength of other mysterious interactions.
Earlier techniques were created to monitor cation-pi(π) interactions in gas conditions where the environment has little effect on the system. Water is present in all biological systems, but only semi-quantitative techniques have been used to evaluate cation-pi(π) interactions in liquid media.
Using Atomic Force Microscopy (AFM)
To circumvent this problem, the team studies the cation-pi(π) interaction for a single molecule using atomic force microscopy (AFM). Researchers have previously shown that the intensity of repulsive contact between a single hydrophobic polymer and water can be evaluated using an AFM. Today, they discovered that it can also be used to investigate the cation-pi(π) interaction.
While the research team was measuring this interaction for lithium, sodium, potassium, and ammonium cations, they discovered that the "togram" of cation-pi(π) binding energy in water was different from that in air.
The team explains this surprising sequence with changes in the hydration properties of the cations. According to the researchers, the findings could guide the creation of materials with greater binding ability and drugs with enhanced efficacy.
Source: physics.aps.org/articles/v16/s36
Günceleme: 18/03/2023 17:34