[Negative cooperativity of 6-phosphogluconate dehydrogenase in rat liver]. / Ob otritsatel'noi kooperativnosti 6-fosfogliukonatdegidrogenazy pecheni krys.

The effect of various NADPH concentrations on the activity of rat liver 6-phosphogluconate dehydrogenase (EC 1.1.1.44) has been studied. The influence of NADPH concentrations on the enzyme cooperativity was observed. NADPH used at concentration up to 200 microM appeared to be a competitive inhibitor with respect to NADP+ without any cooperative effect towards the coenzyme (NADP+) binding. At high concentrations of NADPH (above 300 microM) the negative cooperativity displayed by the enzyme was confirmed by a significant decrease of the Hill coefficient for NADP(+)-from 1.1 +/- 0.2 down to 0.6 +/- 0.1 (p < 0.05).

[Creatine kinase as an index of the body functional state]. / Kreatinkinaza kak pokazatel' funktsional'nogo sostoianiia organizma.

Factors affecting activity and isoenzyme pattern of creatinine kinase in animal tissues, were analysed. Based on the analysis and study of creatine kinase systems at the molecular, cellular, tissue and organism levels, the activity and isoenzyme pattern of creatinine kinase was shown to be able to serve as an indicator of the organism functional state.

[The effect of OCl- and Ag+ on active and passive calcium transport in the sarcoplasmic reticulum]. / Deistvie OCl- i Ag+ na aktivnyi i passivnyi transport kal'tsiia v sarkoplazmaticheskom retikulume.

After hypochlorite (OCl-) treatment of the aortic smooth muscle sarcoplasmic reticulum (SR), the membrane microviscosity increases considerably in "bound" lipid regions in comparison with protein-free regions. OCl- induces the inhibition of active and the enhancement of passive calcium transport in SR. Treatment of SR vesicles with Ag+ and then with OCl- (but not in the reverse order) leads to the enhancement of the activating effect of OCl- on passive calcium release from the vesicles. It is concluded that the enhancement effect is due to the OCl(-)-induced increase in the passive permeability of the SR membrane for Ca2+ as a result of pore formation in the lipid bilayer.

Carnosine as a potential scavenger of oxidants generated by stimulated neutrophils.

Luminol-dependent chemiluminescence of PMA-stimulated human neutrophils decrease more than by 50% in the presence of physiological concentrations of carnosine (20 mM). This inhibition is the result of carnosine ability to scavenge hypochlorite (OCl-), since carnosine exerts a similar effect on chemiluminescence produced by myeloperoxidase-H2O2-Cl- and OCl(-)-H2O2 systems. The previously undocumented property of this dipeptide to scavenge active oxygen species requires further experiments.

Serum protein degradation by hypochlorite.

The structural integrity of serum proteins: albumin, immunoglobulin G, transferrin, ceruloplasmin and superoxide dismutase, and the functional activity of the latter two enzymes after their interaction with hypochlorite were studied. It was shown that the interaction between the proteins and hypochlorite resulted in protein injury and degradation of their native structure. In the case of ceruloplasmin and transferrin, a practically complete protein "dissipation" occurred, the albumin and superoxide dismutase structures being injured in a lesser degree. The inactivation of ceruloplasmin was slower than that of superoxide dismutase. The protein degradation by hypochlorite seems to be the main factor restricting the ability of the proteins to act as antiinflammatory drugs.

[Erythrocyte oxidative damage by myeloperoxidase. The protective action of serum proteins]. / Okislitel'noe povrezhdenie éritrotsitov mieloperoksidazoi. Zashchitnoe deistvie syvorotochnykh belkov.

Influence of main serum proteins (albumin, immunoglobulin G) and proteins-antioxidants (ceruloplasmin, transferrin, superoxide dismutase) on the oxidative damage of erythrocytes by myeloperoxidase and hypochlorite was investigated. The proteins were determined to act as protectors and decrease the degree of hemoglobin oxidation, ceruloplasmin and albumin possessing the highest antioxidant activity.

[Antigenic properties of BB creatine kinases from various tissues in hens]. / Antigennye svoistva BB-kreatinkinaz raznykh tkanei kur.

Studies have been made on interaction between rabbit antiserum to BB creatine kinase from hen gizzard and BB creatine kinases from the brain, heart and gizzard of hen. The degree of interaction was evaluated by the intensity of fluorescence of the immune complexes labeled by a fluorescent dye. It was shown that the intensity of fluorescence of the immune complexes formed by BB creatine kinases from the brain and gizzard of hen is approximately the same, whereas that formed by BB creatine kinase from the heart is twice lower. The data obtained indicate that structural differences in the region of antigenic determinants exist between BB creatine kinase from the heart and those from the brain and gizzard of hen.

A comparative study of serum proteins ability to scavenge active oxygen species: O2-. and OCl-.

The ability of serum proteins (albumin, immunoglobulin G) and protein antioxidants (ceruloplasmin, superoxide dismutase and transferrin) to react with O2-. and OCl-, was studied. The interaction between serum proteins and OCl- was shown to be non-specific. Ceruloplasmin is the most effective OCl- trapping protein, and it reacts with O2-. with a considerable efficiency. Therefore, ceruloplasmin is supposed to be the main scavenger of toxic oxygen species generated by stimulated neutrophils.

[Comparative enzymologic analysis of the creatine kinases from the skeletal muscles of the cod, frog and rabbit]. / Sravnitel'no-énzimologicheskii analiz kreatinkinaz iz skeletnykh myshts treski, liagushki i krolika.

Electrophoretic studies have been made of the protein composition and isozymic pattern of the creatine kinase from muscles of the cod. It was shown that this enzyme constitutes up to 40% of total water-soluble proteins of muscle tissue. Isolation and purification procedures were suggested for the creatine kinase from cod muscles which allow to obtain the enzyme with the specific activity 250-350 IU/mg. Comparative enzymic analysis of creatine kinases from muscle tissue of the cod, lake frog, and rabbit was also made. Studies were carried out on temperature dependence of the reaction, kinetic constants at temperatures 5 and 30 degrees C were determined together with other physicochemical properties of the enzymes. The revealed species specific differences are discussed in relation to the structure and function of the enzymes in lower vertebrates in vivo.

[Antioxidative properties and degradation of serum proteins by active oxygen forms (O2-., OCl-) generated by stimulated neutrophils]. / Antiokislitel'nye svoistva i degradatsiia belkov syvorotki aktivnymi formami kisloroda (O2-., OCl-), generiruemymi stimulirovannymi neitrofilami.

The ability of major serum proteins (albumin, immunoglobulin G) and free radical scavenger proteins (ceruloplasmin, superoxide dismutase, transferrin) to interact with O2-. and OCl- was studied. The interaction between serum proteins and OCl- was shown to be nonspecific and cause protein degradation. During SDS polyacrylamide gel electrophoresis ceruloplasmin and transferrin were degraded in the highest degree. Protein damage was also recorded by fluorescence changes. It is suggested that the damaging influence of active oxygen species secreted by stimulated neutrophils into the extracellular space can be abolished only by ceruloplasmin.

[Various properties of cathepsin G and elastase from swine peripheral blood neutrophils]. / Nekotorye svoistva katepsina G i élastazy iz neitrofilov perifericheskoi krovi svin'i.

Using gel filtration through Sephadex G-100 and bioaffinity chromatography on contrical-Sepharose, cathepsin G and elastase were isolated from pig peripheral blood neutrophil granules and purified to homogeneity. Both enzymes hydrolyzed the total histone from calf thymus as well as synthetic substrates--tert-butoxy-L-alanine p-nitrophenyl ester (elastase) and benzoyltyrosine ethyl ester (cathepsin G). The use of natural and synthetic protease inhibitors showed that both enzymes were related to the group of serine proteases. The molecular mass of the cathepsin G subunit as determined by SDS polyacrylamide gel electrophoresis is 28-29 kD, that of elastase--30-31 kD. The pH optima for the hydrolysis of proteinaceous and synthetic substrates for cathepsin G and elastase are 8.0-8.5 and 7.0-7.5, respectively. The isoelectric points for elastase and cathepsin G are 9.7-10.0 and greater than 10, respectively; the temperature optima--30-40 degrees C and 50-60 degrees C, respectively. The amino acid composition of the two enzymes from pig granulocytes revealed a high content of arginine and was similar to that of human granulocytes.

[Characteristics of luminol chemiluminescence induced by the catalytic action of myeloperoxidase]. / Osobennosti khemiliuminestsentsii liuminola, vozbuzhdaemoi kataliticheskim deistviem mieloperoksidazy.

The effects of pH, luminol myeloperoxidase and hydrogen peroxide concentrations on the intensity of luminol chemiluminescence induced by myeloperoxidase catalysis were investigated. It was found that the intensity of luminescence is proportional to the enzyme concentration (up to 8.10(-8) M) and reaches the saturation level at higher enzyme concentrations. The dependence of chemiluminescence intensity on [H2O2] is bell-shaped: at H2O2 concentrations above 1.10(-4) M the luminescence is inhibited with a maximum at neutral values of pH. Luminol at concentrations above 5.10(-5) M inhibits this process. It was demonstrated that the effects of singlet oxygen, superoxide and hydroxyl radicals on the chemiluminescence reaction are insignificant. Luminol oxidation in the course of the myeloperoxidase reaction is induced by hypochlorite.

[Differences in properties of creatine kinase BB from chicken tissues]. / Razlichiia v svoistvakh BB-kreatinkinaz iz tkanei kur.

BB-creatine phosphokinases (CPK-BB, EC 2.7.3.2) were isolated and purified from the chicken brain, heart and gizzard with specific activities 250-300 IU/mg and equal electrophoretic mobilities. Certain differences in thermal stability, activation energy, Km and optimal temperature of the CPK reaction are shown. The amino acid analysis has also revealed different content of certain amino acids in CPK-BB molecules. The obtained results confirm the existence of tissue-specific heterogeneity in CPK-BB which may be significant for functioning of the phosphocreatine-creatine phosphokinase system in different types of tissues.

[Lysosomal proteins of neutrophils--factors of antimicrobial protection of cells]. / Lizosomal'nye belki neitrofilov--faktory antimikrobnoi zashchity kletok.

Lysosomal antimicrobial factors in neutrophilic granulocytes, components of oxygen-dependent and oxygen-independent mechanisms are considered. Physico-chemical and biological properties om myeloperoxidase, cooperative effect of myeloperoxidase and other cation proteins in neutrophilic lysosomes, interrelation and interaction between various antimicrobial factors in phagocytosis are discussed. Inhibition of the oxygen active forms by means of blood serum proteins is considered.