[The modification of the internucleotide relations of antisignature oligodeoxyribonucleotides as a means of increasing their resistance to nuclease cleavage in mollicute cells].

Modifications in 5'- and 3'-ends and internucleotide bondings of antisignature oligodesoxyribonucleotides have been studied for their resistance to nuclease cleavage in cells of Acholeplasma laidlawii PG-8 and Mycoplasma fermentans PG-18. It is shown that adding of benzylamide grouping to the 5'-end of oligonucleotides increases their half-life period in the studied mollicute cells to 15 h. S-methyl modification of 3'-end of antisignature oligonucleotides did not take essential effect on the process of degradation of the given compounds in the mollicute cells. Considerable increase of stability in the studied cels of thio- and dithiophosphate analogues of oligodesoxyribonucleotides has been detected.