Gaining insights into charge transport related to conformational changes and ion transport in valinomycin(VM)is crucial for understanding the underlying physiological processes and advancing ion carrier applications.O...Gaining insights into charge transport related to conformational changes and ion transport in valinomycin(VM)is crucial for understanding the underlying physiological processes and advancing ion carrier applications.Observing these processes in single molecules provides deeper insights and precision than those obtained through conventional ensemble measurements.Herein,we employed a single-molecule conductance measurement method based on the scanning tunneling microscopy break-junction(STM-BJ)to measure the charge transport of individual VM molecules in both non-polar and polar solvents,as well as when mediated by K^(+)ions.Single-molecule conductance measurements revealed that the bracelet and propeller-type conformations of VM in both non-polar and polar solvents significantly affect its conductance.In polar solvents,the propeller-type conformation of VM demonstrated a well-defined conductance signature,single-molecule rectification feature,and through-space transmission mechanism.Specifically,the introduction of K^(+)ions in polar solvents induced a conformational transition from the propeller-type to the bracelet-type form,facilitating K^(+)binding recognition.These observations were further supported by density functional theory combined with non-equilibrium Green’s function calculations.This study enhanced the fundamental understanding of the electronic transport mechanisms in VM and valinomycin-K^(+)molecular junctions,offering insights into VM ionophores and promoting supramolecular sensing applications.展开更多
The aim of this work is to estimate the value of the electric field (potentials) for the system of valinomycin + К+ and Na+ ions based on a molecular dynamics (MD) study. An analysis has been performed of the interac...The aim of this work is to estimate the value of the electric field (potentials) for the system of valinomycin + К+ and Na+ ions based on a molecular dynamics (MD) study. An analysis has been performed of the interaction processes for the system of valinomycin + К+(Na+) ion in water solvent. It is obtained that capturing a К+(Na+) ion in the valinomycin cavity is not possible for all values of the electric field strength. Each of the two kinds of ions (К+ or Na+) has its own critical electric field associated with ion binding to valinomycin, for which to exist, the ion has to remain localized inside the valinomycin cavity. The results obtained for the electrical potential reveal a stronger valinomycin binding—especially with the potassium ion. Valinomycin’s molecular structure efficiently surrounds the K+ ion, as this structure has to exactly correspond to the K+ ion in size. MD simulation results could be a prerequisite for studying a more complex scenario—for estimating ion transport in the cell membrane or physiological electric potential which is formed in the membrane or inside the cell relative to its surrounding medium.展开更多
Fused-silica capillary column containing valinomycin and OV-1701(mass ratio 15∶85) as a new stationary phase component was(prepared.) The column was thermal stable below 176 ℃,the average value of McReynold constant...Fused-silica capillary column containing valinomycin and OV-1701(mass ratio 15∶85) as a new stationary phase component was(prepared.) The column was thermal stable below 176 ℃,the average value of McReynold constants was 157,and its column efficiency was 2 083 plate/m when the retention factor was(2.20.) Some aromatic(positional) isomers and chiral compounds,such as cresol,xylene,nitrotoluene,D,L-valine,D,L-leucine,(±)isopinocampheol,(±)roseoxide,(±)dihydrocaruvyl acetate were separated.It showed excellent(selectivity) toward aromatic positional(isomers) and chiral compounds.展开更多
基金supported by the National Key R&D Program of China(Nos.2022YFB3204402,2020YFA0714703 and 2022YFC2205003)the National Natural Science Foundation of China(No.22204135)+2 种基金Hunan Provincial Natural Science Foundation of China(No.2023JJ40619)the Education Department of Hunan Province(No.23A0114)the Science and Technology Innovation Program of Hunan Province(No.2022RC3027)。
文摘Gaining insights into charge transport related to conformational changes and ion transport in valinomycin(VM)is crucial for understanding the underlying physiological processes and advancing ion carrier applications.Observing these processes in single molecules provides deeper insights and precision than those obtained through conventional ensemble measurements.Herein,we employed a single-molecule conductance measurement method based on the scanning tunneling microscopy break-junction(STM-BJ)to measure the charge transport of individual VM molecules in both non-polar and polar solvents,as well as when mediated by K^(+)ions.Single-molecule conductance measurements revealed that the bracelet and propeller-type conformations of VM in both non-polar and polar solvents significantly affect its conductance.In polar solvents,the propeller-type conformation of VM demonstrated a well-defined conductance signature,single-molecule rectification feature,and through-space transmission mechanism.Specifically,the introduction of K^(+)ions in polar solvents induced a conformational transition from the propeller-type to the bracelet-type form,facilitating K^(+)binding recognition.These observations were further supported by density functional theory combined with non-equilibrium Green’s function calculations.This study enhanced the fundamental understanding of the electronic transport mechanisms in VM and valinomycin-K^(+)molecular junctions,offering insights into VM ionophores and promoting supramolecular sensing applications.
文摘The aim of this work is to estimate the value of the electric field (potentials) for the system of valinomycin + К+ and Na+ ions based on a molecular dynamics (MD) study. An analysis has been performed of the interaction processes for the system of valinomycin + К+(Na+) ion in water solvent. It is obtained that capturing a К+(Na+) ion in the valinomycin cavity is not possible for all values of the electric field strength. Each of the two kinds of ions (К+ or Na+) has its own critical electric field associated with ion binding to valinomycin, for which to exist, the ion has to remain localized inside the valinomycin cavity. The results obtained for the electrical potential reveal a stronger valinomycin binding—especially with the potassium ion. Valinomycin’s molecular structure efficiently surrounds the K+ ion, as this structure has to exactly correspond to the K+ ion in size. MD simulation results could be a prerequisite for studying a more complex scenario—for estimating ion transport in the cell membrane or physiological electric potential which is formed in the membrane or inside the cell relative to its surrounding medium.
文摘Fused-silica capillary column containing valinomycin and OV-1701(mass ratio 15∶85) as a new stationary phase component was(prepared.) The column was thermal stable below 176 ℃,the average value of McReynold constants was 157,and its column efficiency was 2 083 plate/m when the retention factor was(2.20.) Some aromatic(positional) isomers and chiral compounds,such as cresol,xylene,nitrotoluene,D,L-valine,D,L-leucine,(±)isopinocampheol,(±)roseoxide,(±)dihydrocaruvyl acetate were separated.It showed excellent(selectivity) toward aromatic positional(isomers) and chiral compounds.
