\n\t\tSummary

\n\t\tStudy of Possibility to Express Cytotoxic Activity

\n\t\tof RNase from cobra (naja naja) venom

\n\t\tRecently interest in ribonucleases was renewed after some members of RNase A (bovine pancreatic ribonuclease) superfamily were shown to possess many other important biological activities besides their degrading action on RNAs. Among these new biological activities cytotoxicity seems to be the most interesting one because its structural basis can serve for creation of new pharmaceuticals for cancer therapy.

\n\t\tIn this paper we have investigated the influence of human placenta ribonuclease inhibitor (RI) on the activity of RNase in the whole cobra venom and of the two main RNase forms, purified from crude venom by chromatographic separation on the CM-cellulose column (These RNase forms were eluted from the column at salt concentrations of 0.60-0.65M and 0.80-0.85M NaCl and they were designated as SK-2 and SK-3, respectively). The obtained results showed that human placenta RI completely inhibited activity of RNase from pig pancreas, but had no effect on the activity of RNase in the whole snake venom and its separate forms. These data allowed to conclude that Vietnam cobra venom RNase did not interact with cytoplasmic RI and can express cytotoxic activity.