pap-c inactivates ribosomes in a less-than-equimolar ratio , thus inhibiting protein synthesis by a rabbit reticulocyte lysate with an ic50 ( concentration causing 50 % inhibition ) of 0.067 nm ( 2 ng/ml ) , and modifies rrna in a manner apparently identical to that of ricin and other ribosome-inactivating proteins .
C0035553
ribosomes
C0035701
rrna