卷 60, 编号 6 (2024)

The Gag polyprotein is the main structural protein of the human immunodeficiency virus (HIV). It is responsible for the assembly of new viral particles in the infected cell. This process occurs on the plasma membrane of the cell and is largely regulated by the interactions of Gag with the lipid matrix of the cell membrane. In this work, using the inner field compensation method and electrokinetic measurements of the zeta potential in a liposome suspension, we studied the binding of the HIV non-myristoylated Gag polyprotein to model lipid membranes. To quantify protein affinity for charged and uncharged lipid bilayers, Gag adsorption isotherms were obtained and binding constants were calculated. It has been shown that this protein is able to interact with both types of membranes with approximately the same binding constants (K_PC = 8 × 10⁶ M^–1 and K_PS = 3 × 10⁶ M^–1). However, the presence of the anionic lipid phosphatidylserine in the lipid bilayer significantly enhances protein adsorption on the membrane due to the additional influence of the surface potential jump it creates near the membrane (K_PS^eff = 37.2 × 10⁶ M^–1). Thus, the interaction of Gag with membranes is determined rather by hydrophobic interactions and the area per lipid molecule, while the presence of a negative surface charge only increases the concentration of the positively charged protein near the membrane.

In this work, the electrochemical and electrocatalytic behavior of gold electrodes modified with nickel(II) (NiPc) and copper(II) (CuPc) tetra-4-sulfophthalocyaninates in an aqueous alkaline solution was studied using cyclic voltammetry. A comparative assessment of the electrocatalytic activity of the studied metal phthalocyaninates in the oxidation reaction of hydroxide ions with the formation of molecular oxygen is given, and a comparison is made with literature data.

Photosensitive hybrid layers were obtained by electrochemical polymerization of pyrrole and 3,4-ethylenedioxythiophene (EDOT) in the presence of water-soluble sodium salt of zinc octa(3ʹ,5ʹ-dicarboxyphenoxy)phthalocyaninate (ZnPc) containing 16 ionogenic carboxylate groups. It was found that the process of electrodeposition of hybrid layers most effectively occurs in galvanostatic and potentiostatic modes on the sublayer of the PEDOT-polyacid complex. The electronic and chemical structure and morphology of hybrid layers of polypyrrole (PPy) obtained in the presence of ZnPc were studied. Possible reasons are considered that the measured values of photosensitivity and external quantum yield of charge carrier generation in PPy-ZnPc are several times higher than in PEDOT-ZnPc.

Silver(I) oxide is considered as one of the promising materials for photoelectrochemical technologies, since it is characterized by an optimal band gap, relatively low cost, and a wide range of production methods. However, its characteristics such as quantum efficiency, morphology and crystal structure parameters require optimization, which can be achieved by applying the most suitable method for obtaining the material. One of the fairly simple methods is the anodic oxidation of silver or its alloys in an alkaline medium, which makes it possible to obtain oxide phases with a controlled composition and predictable properties by varying the concentration of alloy components and electrolysis mode. The purpose of this work is to reveal the features of anodic formation and to determine the photoelectrochemical characteristics of silver (I) oxide on silver alloys with palladium in deaerated 0.1 M KOH. The regularities of the anodic formation of Ag(I) oxide on alloys of the Ag-Pd system with an atomic fraction of palladium from 0.05 to 0.20 in deaerated 0.1 M KOH were studied by non-stationary electrochemical methods of cyclic voltammetry, chronoamperometry with synchronous recording of photocurrent, and measurement of photopotential. The phase composition of the alloys (alpha phase) was determined from the results of X-ray diffractometry. Сhemical composition was determined by energy dispersive microanalysis. Photoelectrochemical parameters were calculated from the results of measuring the photocurrent and photopotential. It was established that the Ag(I) oxide anodically formed on silver-palladium alloys is characterized by n-type conductivity and the predominance of donor defects. On alloys with a relatively low concentration of palladium (5 and 10 at. %), Ag(I) oxide with a higher concentration of defects is formed, while on alloys with a relatively high concentration of palladium (15 and 20 at. %), with a lower concentration of defects than on silver.