nteractions of the cytotoxic RNase A dimers with the cytosolic ribonuclease inhibitor.

RNase A dimers have been recently found to be endowed with some of the special, i.e., non-catalytic biol. activities of RNases, such as antitumor and aspermatogenic activities. These activities have been so far attributed to RNases which can escape the neutralizing action of the cytosolic RNase inhibitor (cRI). However, when the interactions of the two cytotoxic RNase A dimers with cRI were investigated in a quant. fashion and at the mol. level, the dimers were found to bind cRI with high affinity and to form tight complexes.