Biopolymers and cell. 1991. Volume 7. № 5. 37 - 42

VLASSOV V. V., ZARYTOVA V. F., IVANOVA E. M., KRENDELEV Yu. D., OVANDER M. N., RYTE A. S.

The Effect of Modification of Terminal Groups of Oligonucleotides on Their Stability in Mycoplasma Culture

Summary

    The effect of modification of terminal groups of deoxyribooligonucleotides on their sta¬bility in culture medium and mycoplasma cells A. laldlawii PQ-8 and M. capricolum California kid has been investigated. The oligonucleotides and their derivatives were stable in culture medium with 10 % horse serum during 24 hours. In the medium with mycoplasms, orthophosphates were rapidly removed from the 5'-ends and the oligo¬nucleotides degraded to mononucleotides. In the cells, the scission of 5'-phosphomono-ester bonds was accompanied by reutilization of the phosphate. Attachment of the cho¬lesterol or phenazinium residues to oligonucleotides 3'- or 5'-ends protected them from nucleases. The modification of oligonucleotides 5'-ends by 5'-phosphoramides formati¬on, protect the oligonucleotides from dephosphorylation and slower the degradation down. Oligonucleotides protected from 3'- or 5'-ends are more stable to mycoplasma nucleases.