Hysteretic interaction of NADH and Mg2+ with mammalian NADH:CoQ reductase from beef heart.

Preincubation of submitochondrial particles (SMP) from beef heart in a reaction mixture containing low concentrations of Mg2+ induces a time lag in the NADH:oxidase activity. Preconditioning of the SMP by NADH, but not by NAD+, prevents the Mg2+-related time lag. The data obtained show that there exists a tight binding site for Mg2+ regulating the rate of electron transfer from NADH to the natural acceptor. The ability of Mg2+ to form a catalytically inactive complex with the enzyme is regulated by NADH.

[Change in lipid peroxidation, structural status and level of phospholipids in the blood of patients with fibroma and cancer of the uterus]. / Izmenenie perekisnogo okisleniia lipidov, strukturnogo sostoianiia i soderzhaniia fosfolipidov v krovi bol'nykh fibromoi i rakom tela matki.

Study of physicochemical properties of lipids in the donor blood and blood of patients with fibroma and uterus cancer showed that the progress of pathological processes may lead to the rise of peroxidation and peroxide accumulation, phospholipid balance disturbance, that causes drastic changes in biomembranes. As a result of this the disturbance of the structure and change in the functional activity of the membranes take place.

[Phospholipid composition of blood lipids in breast and uterine cancer]. / Izuchenie fosfolipidnogo sostava lipidov krovi pri rake molochnoi zhelezy i tela matki.

A comparative analysis of quantitative changes in phospholipids, as well as peroxidation of undiluted blood lipids, plasma and blood cells in healthy women, those suffering from breast and uterus cancer, and from nonmalignant tumours (breast fibroadenoma and uterus fibroma) does not show any specific regularity typical of only malignant neoplasma and not typical of nonmalignant ones. Disturbances in the balance of negative charge phospholipids are supposed to change the electrostatic interaction in the lipid-protein complexes of supramolecular structures during the malignant growth.

[Characteristic of the sites of benz(a)pyrene binding with lysosomal membranes]. / O prirode tsentrov sviazyvaniia benz(a)pirena s membranami lizosom.

Formation of complexes between carcinogenic polycyclic hydrocarbons and lysosomal membranes, exhibiting high inhibitory activity, was studied. Separation of lysosomal membranes into protein and lipid moities and further study of their inhibitory activity enabled to demonstrate that the fraction of lysosomal lipids was responsible for the phenomenon. Elimination of membrane lipids decreased the binding of benz(alpha)pyrene with lysosomes. The carcinogen entering into lysosomal membrane appears to substitute cholesterol in the phospholipid complex, being introduced in the fatty acid chain of phospholipids, thus altering the conformation of protein and protein-lipid complexes in the lysosomal membrane with the subsequent liberation of the lysosomal hydrolytic enzymes into cytoplasm.

[DNA-cholesterol complex studied by fluorescent probes]. / Izuchenie kompleksa DNK--kholesterin metodom fluorestsentnykh zondov.

DNA interaction with cholesterol at various lipid concentrations has been investigated by the fluorescent probes method. It has been shown that the intensity of acridine orange fluorescence in the DNA-cholesterol complex decreases at 24 micrograms/ml cholesterol and at 45 micrograms/ml it increases. The number of binding sites and the degree of polarization of fluorescence change simultaneously. Binary mechanism of cholesterol binding with DNA has been suggested: surface binding takes place at low concentrations, intercalation--at high lipid concentrations.

[Thermoinduced structure reconstructions in lysosomal membranes and lipids during experimental carcinogenesis]. / Izuchenie termoindutsirovannykh strukturnykh perestroek v membranakh i lipidakh lizosom pri éksperimental'nom kantserogeneze.

Thermoinduced structural transitions in lyzosome membranes and lipids during experimental cancerogenesis were considered. Unlike lipid aqeous systems the structural transitions in lipids were investigated in inside out turned with hydrophobic side vesicles in apolar and aproton solvent. Relationship between the structure change and the function of lyzosome membranes is discussed.