Antimitotic action of cornin as a biologically active polypeptide. II. Physiological effects of cornin on dividing cell

Both the cornea and muscle cornins have no effect at all on oxygen uptake of tissue, and likewise they catalase affect Qctivity not in any way. The corneacornin has an effect to reduce P/O ratio to about one half, but the muscle cornin does not show such an effect. Both comins decrease thc incorporation of P³² into nucleic acid fraction and DNA synthesis. In the ultracentrifugal analysis of nucleic acids during development of sea urchin eggs, cornins inhibit the polymerization of nucleic acids. In addition, both of these comins depress the incorporation of P³² into DNA and ribosome RNA of regenerating rat liver. Both comins inhibit the increase of -SH quantities before the cleavage of sea urchin eggs.