Characterization of conformation kinetics of proteins at the interfaces is crucial for understanding the biornolecular functions and the mechanisms of interfacial biological action. But it requires to capture the dyna...Characterization of conformation kinetics of proteins at the interfaces is crucial for understanding the biornolecular functions and the mechanisms of interfacial biological action. But it requires to capture the dynamic structures of proteins at the interfaces with suffi- cient structural and temporal resolutions. Here, we demonstrate that a ferntosecond sum frequency generation vibrational spectroscopy （SFG-VS） system developed by our group provides a powerful tool for monitoring the real-tirne peptide transport across the membranes with time resolution of less than one second. By probing the real-time SFG signals in the arnide I and arnide A bands as WALP23 interacts with DMPG lipid bilayer, it is found that WALP23 is initially absorbed at the gel-phase DMPG bilayer with a random coil structure. The absorption of WALP23 on the surface leads to the surface charge reversal and thus changes the orientation of rnembrane-bound water. As the DMPG bilayer changes from gel phase into fluid phase, WALP23 inserts into the fluid-phase bilayer with its N-terminal end moving across the membrane, which causes the membrane dehydration and the transition of WALP23 conformation from random coil to mixed helix/loop structure and then to pure α-helical structure. The established system is ready to be employed in characterizing other interracial fast processes, which will be certainly helpful for providing a clear physical picture of the interracial phenomena.展开更多
基金supported by the National Natural Science Foundation of China(No.21473177,No.21633007)the National Key Research and Development Program of China(No.2017YFA0303500 and No.2018YFA0208700)+1 种基金Fundamental Research Funds for the Central Universities(No.WK2340000064)Anhui Initiative in Quantum Information Technologies(No.AHY090000)
文摘Characterization of conformation kinetics of proteins at the interfaces is crucial for understanding the biornolecular functions and the mechanisms of interfacial biological action. But it requires to capture the dynamic structures of proteins at the interfaces with suffi- cient structural and temporal resolutions. Here, we demonstrate that a ferntosecond sum frequency generation vibrational spectroscopy （SFG-VS） system developed by our group provides a powerful tool for monitoring the real-tirne peptide transport across the membranes with time resolution of less than one second. By probing the real-time SFG signals in the arnide I and arnide A bands as WALP23 interacts with DMPG lipid bilayer, it is found that WALP23 is initially absorbed at the gel-phase DMPG bilayer with a random coil structure. The absorption of WALP23 on the surface leads to the surface charge reversal and thus changes the orientation of rnembrane-bound water. As the DMPG bilayer changes from gel phase into fluid phase, WALP23 inserts into the fluid-phase bilayer with its N-terminal end moving across the membrane, which causes the membrane dehydration and the transition of WALP23 conformation from random coil to mixed helix/loop structure and then to pure α-helical structure. The established system is ready to be employed in characterizing other interracial fast processes, which will be certainly helpful for providing a clear physical picture of the interracial phenomena.
