[Specificity of synthetic polyribonucleotides hydrolysis by endoribonuclease from cobra (Naja oxiana) venom]. / Osobennosti gidroliza sinteticheskikh poliribonukleotidov éndoribonukleazoi iz iada kobry Naja oxiana.

An analysis of kinetic differences in homopolyribonucleotides hydrolysis by cobra venom endoribonuclease was carried out. It was concluded that the rate and intensity of hydrolysis as well as the length of the linear parts of the kinetic curves are correlated with the content of the nucleotide units with the C3'-endo conformation in the substrates. The structure factor was shown to predominate in some cases over the temperature factor. Protamine sulfate inhibits the enzyme by blocking its phosphodiether bonds. Study on the effects of divalent metal ions demonstrated the possibility that the enzyme-Me2+ complex is functionally active and that the ion-free polyribonucleotides are true substrates.

[Use of liposomes for incorporation of alkylating derivatives of mono- and oligonucleotides into mammalian cells]. / Ispol'zpvanie liposom dlia vvedeniia alkiliruiushchikh proizvodnykh monoi oligonukleotidov v kletki mlekopitaiushchikh.

It was shown that within the liposomes mono- and oligonucleotides and their alkylating derivatives penetrate the cells of Ehrlich ascite carcinoma and peritoneal exudate of the mice. Inside the cells the alkylating reagents are mainly utilized for modification of proteins (42--76%), RNA (5--16%) and DNA (3--9%). Presumably DNA modification is largely dependent on the penetration of the reagents into the nuclei. No significant differences in alkylation of the cell components by oligoadenylate derivatives, capable of complementary interactions with nucleic acids and mononucleotide derivatives, incapable of such interactions, were observed.