[Nucleoside diphosphate kinase from bovine retina is a glycoprotein]. / Nukleoziddifosfatkinaza setchatki byka iavliaetsia glikoproteinom.

Nucleoside diphosphate (NDP) kinase from bovine retina was found to contain carbohydrates. The subunits of NDP kinase were separated by SDS-PAGE, blotted onto an Immobilon-P membrane, and their carbohydrate content was determined. Both subunits contained equal amounts of Gal, Man, Fuc, Gal-NAc, and Glc-NAc. The total carbohydrate content was 2 to 3% of the protein weight.

[Inhibition of human MS and BRO melanoma cell proliferation by alpha melanocyte stimulating hormone]. / Ingibirovanie proliferatsii melanomnykh kletok cheloveka MS i BRO alpha-melanotsitstimuliruiushchim gormonom.

Effect of alpha-melanocyte stimulating hormone (MSH) on proliferating activity of MS and BRO melanoma cell strains with dissimilar phenotype was studied. MSH, apart from the effect on melanomagenesis, influenced the cell proliferation. Growth of MS cells was inhibited at 10(-8)-10(-9) M concentrations of the hormone (IC50 = 2.10(-8) M), while BRO cells were activated. The higher concentrations of MSH inhibited also BRO cells growth (IC50 = 9.10(-7) M). Ligand-receptor interaction of 125I = MSH with plasmatic membranes and cytosol fraction of the cells was studied at 4 degrees and 37 degrees.

[Heterogeneity of tyrosinases isolated from rat skin, normal human skin, and human melanoma tumors]. / Geterogennost' preparatov tirozinazy, vydelennykh iz kozhi krys, kozyi i melanomnykh opukholei cheloveka.

An electrophoretically homogeneous preparation of tyrosinase (Mr = 61 kDa) was isolated from rat skin. The purification procedure which consisted in chromatographic separation of Triton X-100-solubilized proteins included four main steps, namely: gel filtration, anion-exchange chromatography and two consecutive affinity chromatography steps. Isoelectrofocusing revealed the presence of 9 isoforms possessing an L-DOPA oxidase activity, of which proteins with pI of 4.26 and 4.33 were the major ones. The specific activity of the preparation was 43 nmol/min/mg of protein. Human skin epidermis was practically devoid of the L-DOPA-oxidase activity which was due not only to the absence of tyrosinase but also to the presence of a large amount of a 66 kDa protein able to inhibit the oxidation of L-DOPA to DOPA-chrom. The tyrosinase preparation from human melanoma consisted, predominantly, of two isoforms (48 and 69 kDa) which upon isoelectrofocusing displayed a high heterogeneity at pH around 3-5. The specific activity of the melanoma preparation markedly exceeded that of normal skin tyrosinase and was equal to 290 nmol/min/mg of protein.

[The expression of P-glycoprotein in leukemia P388 cells with induced doxorubicin resistance]. / Ekspressiia P-glikoproteina v kletkakh leikoza P 388 s indutsirovannoi ustoichivost'iu k doksorubitsinu.

beta-D-galactose-containing glycoproteins were prepared from cells P-388 leukemia and from P-388 leukemia cells with induced resistance to doxorubicin. It was shown by HPLC method that plasma membranes from resistant cells contain 4-4.5% P-glycoproteins and plasma membranes from sensitive cells contain P-glycoproteins about 10 times lower.

[Initiation of nonenzymatic lipid peroxidation in a Fe2+-ascorbate-linolenate system]. / Initsiirovanie nefermentativnogo perekisnogo okisleniialipidov v sisteme Fe2+-askorbat-linolenat.

Using spin trapping method there were discovered and identified the radicals of linolenic acid formed when initiating its peroxidation by the system Fe2+-ascorbate. Mechanism of formation of linolenic acid radicals and their role in initiation of peroxidation were studied. A scheme of reactions of peroxidation initiation in the system Fe2+-ascorbate. linolenic acid is proposed.

[Study of radicals formed in the interaction of organic hydroperoxides with ferric ions using the spin trap method]. / Issledovanie radikalov, obrazuiushchikhsia pri vzaimodeistvii organicheskikh gidroperekisei s ionami zheleza, metodom spinovykh lovushek.

The mechanism of free radical generation in the reaction of ferrous ion with t-butyl and linolenic acid hydroperoxide was investigated by spin trapping method. The t-butoxyl, methyl, linolenic acid alkoxyl and alkyl radical spin adducts EPR spectra were observed and identified.