Binding of zinc cations to human serum gamma-globulin.

Binding of zinc cations to human serum gamma-globulin was studied by molecular ultrafiltration. The content of free metal in the filtrate was evaluated by reaction with o-phenanthroline. Conformation characteristics of the protein were determined by UV spectrophotometry. Our findings suggest that gamma-globulin molecule contains several zinc binding sites differing by corresponding constants and successively occupied with increase in the content of bound metal. The parameters of zinc binding correspond to those obtained in experiments with copper. Conformation status of protein with bound zinc differs significantly from that of protein with bound copper cations.

Human serum gamma-globulin binds copper cations.

Binding of copper cations to human serum gamma-globulin was studied using molecular ultrafiltration. The content of free metal in the filtrate was evaluated by the reaction with sodium diethyldithiocarbamate. Conformation characteristics of the protein were evaluated by UV spectrophotometry. gamma-Globulin molecule has several copper-binding sites differing by binding constants and filled one-by-one as the content of bound metal increased.

Preparation of specimens of human serum gamma-globulin modified by copper and zinc and its immunochemical characteristics.

Specimens of human serum gamma-globulin modified by molar excess of copper and zinc cations were obtained by molecular ultrafiltration. Conformation characteristics of the protein were determined by UV spectrophotometry. Immunochemical study included radial immunodiffusion test and direct and sandwich enzyme-linked immunosorbent assay. After binding of copper and zinc, the gamma-globulin molecule underwent conformation changes modifying presentation of antigenic determinants on the globule surface and their availability for recognition by specific antibodies. The effects of copper were much more pronounced than those of zinc cations.

Reactions between human serum gamma-globulin and zinc cations.

Interactions of human serum gamma-globulin with zinc cations in solution were studied by differential spectrophotometry in UV light. Supraphysiological concentrations of zinc caused an increment in optical density of protein solution reflecting the effect of gamma-globulin saturation with the metal. Zinc concentrations below physiological led to hypochromism in the protein absorption spectrum. Conformation changes in gamma-globulin during interactions with zinc are analyzed for the surface and intramolecular binding sites and are compared with the effects of copper cations.

Biphasic interaction of gamma-globulin with copper cations.

Interactions of human serum gamma-globulin with copper cations in solution were studied by differential ultraviolet spectrophotometry. Copper in supraphysiological concentrations increases optical density of protein solution, reflecting the effect of gamma-globulin saturation with metal. In physiological and lower concentrations of copper cations we observed hypochromia in the protein absorption spectrum. Conformational changes in g-globulin molecule during interactions with copper by the surface and intramolecular binding sites and possible role of bivalent metal cations in the maintenance of certain conformations of immunoactive serum proteins are discussed.

Formation of supramolecular aggregations of gamma-globulin as a metal-dependent process.

The presence of copper cations in the solution of human serum gamma-globulin induced the formation of supramolecular forms of the protein. The intensity of this reaction increased with increasing copper concentration. The mechanisms of g-globulin aggregate formation under normal conditions and the possible role of bivalent metal cations in the regulation of protein effector functions are discussed.

[Association of Candida albicans fungi with some opportunistic microorganisms in intestinal dysbiosis in patients of different age groups].

The occurrence of C. albicans in association with opportunistic microorganisms (Staphylococcus aureus and Klebsiella) in intestinal dysbiosis in patents of different age groups (from 6 days to 31 years) was analyzed. The data on the comparative evaluation of the results of the bacteriological examination of patients with intestinal dysbiosis, carried out during the periods of 2000-2001 and 2001-2002 (388 and 467 patients respectively), are presented. During the period of 2000-2001 the detection rate of C. albicans in monoculture was 6-33% of cases (in the examined group). A higher detection rate was registered with respect to the association of C. albicans with staphylococci (42-65% of cases). The associations of C. albicans with staphylococci and Klebsiella were observed in 13-46% of cases. Similar results were registered during the period of 2001-2002, but during this period a reliable decrease in the detection rate of the association of C. albicans with staphylococci (practically by 20% in the group of infants) and the 1 1/2-fold increase of the detection rate of C. albicans in monooulture (in all age groups) were observed.

Activity of human lymphocytes in the presence of carbohydrate-containing compounds.

Treatment with chelating agent abolished stimulation of human lymphocyte blast transformation observed in the presence of native microbial glycoproteins. Heparin passed through a column packed with aluminum hydroxide inhibited cytotoxic activity in natural killer cells. We discuss the possibility of regulation of cell functions via modulation of the vector of transport and exchange of metal cations in cell microenvironment and the role of macromolecular compounds containing carbohydrate components in this process.

[Antigenic determinants of normal serum proteins bound to the surface antigen structures of the serum hepatitis B virus (HBsAg)]. / Antigennye determinanty normal'nykh syvorotochnykh belkov, sviazanny so strukturami poverkhnostnogo antigena virusa syvorotochnogo gepatitia B (HBsAg).

The coprecipitation test under conditions of rocket immunoelectrophoresis was used for the analysis of human normal serum antigens associated with HBsAg structures. Antigenic determinants of human serum albumin were detected in the HBsAg composition. In the multicomponent test system, 125I-HBsAg coprecipitated with some more distinct antigenic systems in addition to albumin. Possible mechanisms of formation of classes of HBsAg structures differing in host antigens are discussed.

[Host antigens in the composition of the surface antigen structures of the serum hepatitis virus type B(HBsAg)]. / Antigeny khoziaina v sostave struktur poverkhnostnogo antigena virusa syvorotochnogo gepatita tipa B(HBsAg).

In competitive radioimmunoassay of purified HBsAg preparations less than 1% of normal human serum antigens was found in weight equivalents. In radioimmune precipitation 125I-HBsAg was precipitated by antiserum to normal human serum proteins. The use of successive precipitation of the label with virus-specific and polyprecipitating antisera established the association of the detected antigenic determinants of the host with some portion (52%) of HBsAg structures.

A vaccine prepared from the 22 nm particles of surface hepatitis B antigen (HBsAg).

A method for obtaining a subunit inactivated vaccine preparation from the 22-nm particles of HBsAg is proposed. For inactivation of the residual infectious hepatitis B virus (HBV) the preparations were successively treated with 1% sodium dodecyl sulfate (SDS) and nucleases. In addition, thermal denaturation and ultraviolet irradiation of HBV DNA were used. As a control the biologic activity of a reference virus (SV40) was tested after the same treatment. The effectiveness of DNA inactivation was monitored by adding 3H-thymidine labeled reference virus to the vaccine preparations. The purified and inactivated HBsAg was adsorbed on Al2O3. Antigenicity was calculated on the basis of the determination of antibody in guinea pigs immunized with various doses of the vaccine, and the release of 125I- HBsAg from blood and kidneys in immunized and control mice was analyzed. Possible methods of inactivation and control of HBV vaccine is discussed.

[Isolation of hepatitis B (HBSAg) from donor blood plasma]. / Vydelenie poverkhnostnogo antigena gepatita B (HBSAg) iz plazmy krovi donorov.

An original method for purification of HBsAg from the blood plasma of donors is described. Preparations have been obtained containing structures 22 nm in size the proteins of which form 9 bands in polyacrylamide gel electrophoresis and containing no detectable amounts of admixtures accompanying HBsAg. The purified HBsAg meets the requirements for test-antigens for radioimmuniassay and immune autoradiography. The reported method may be used for preparation of HBsAg under production conditions.

[Radioimmunoassay for detection of hepatitis B surface antigen]. / Radioimmunologicheskii metod indikatsii poverkhnostnogo antigena gepatita B.

A modification of radioimmunoassay (RIA) for detection of HBsAg is described. The schedule for purification and the method of iodinization of purified HBsAg are presented. The sensitivity of RIA and other immunological methods for detection of HBsAg was analysed comparatively. RIA in the modification described detected HBsAg in a concentration of 50 mg/ml.

[Comparative analysis of gamma globulin preparations isolated by means of DEAE-Sephadex and DEAE-cellulose]. / Sravnitel'nyi analiz preparatov gamma-globulina, vydelennykh s pomoshch'iu DEAE-sefadeksa i DEAE-tselliulozy

Preparations of rabbit gamma-globulin obtained with the aid of ion-exchange chromatography on DEAE-Sephadex contained an admixture of other serum proteins revealed by disc-electrophoresis in acrylamide gel. This impurity can be eliminated by rechromatography of gamma-globulin preparations of DEAE-cellulose in the same buffer solutions which were used for purification of gamma-globulin on DEAE-Sephadex. Better purification of gamma-globulin on DEAE-cellulose can supposedly be attributed to the effective absorption on cellulose basis of euglobulin aggregates which form in the solutions with a low ionic power used for chromatographic isolation of gamma-globulin on ion-exchangers.