Using surface-enhanced infrared absorption spectroscopy in conjunction with electrochemical techniques,this study investigates the origins of variations in electrocatalytic activity of 4-nitrothiophenol(4-NTP)under the influence of three cations:Li+,Na+,and tetramethylammonium(TMA+).The findings highlight the significant impact of specific interactions between cations and the electrode surface on electrocatalytic activity.By constructing vibrational Stark spectra,the study reveals the impact of cations on the structure of the electric double layer and the interfacial electric field.Further spectroscopic and electrochemical characterizations demonstrate that differences in the hydrophilic and hydrophobic properties of cations influence their specific interactions with the interface.Notably,TMA+,through specific interactions,acts as a mediator for charge transfer,effectively reducing the charge transfer resistance of the system and thereby enhancing electrocatalytic activity to some extent.These results elucidate the influence of specific cation/interface interactions and cation properties on electrocatalytic reactions,contributing to a deeper understanding of cation effects at electrochemical charged interfaces.

OBJECTIVETo construct a yeast expression vector of hepatitis B virus (HBV) PreS1 gene using the Sos-recruitment system (SRS), and evaluate the effect of the expression product on the growth of the yeast cells and activation of the reporter gene.

METHODSThe coding sequence of HBV preS1 was amplified by PCR and cloned into the yeast expression plasmid pSos. The recombinant bait plasmid pSos- PreS1 was verified by sequencing before transformation into competent yeast cells. The effects of the expression product on the yeast cell growth and activation of the reporter gene were evaluated.

RESULTSThe yeast expression vector of HBV PreS1 gene was constructed successfully. The recombinant bait plasmid showed no toxic effect on yeast cdc25H cells without a self-activation of the reporter gene.

CONCLUSIONThe SRS can be used to study the proteins interacting with HBV PreS1 protein and provides a means for obtaining insight into the pathogenic mechanism of HBV.

Cloning, Molecular ; Genetic Vectors ; genetics ; Hepatitis B Surface Antigens ; biosynthesis ; genetics ; Humans ; Plasmids ; genetics ; Protein Precursors ; biosynthesis ; genetics ; Receptors, Virus ; metabolism ; Recombinant Fusion Proteins ; biosynthesis ; genetics ; Two-Hybrid System Techniques ; Yeasts ; genetics ; metabolism