Dephosphorylation of Nucleic Acids, Mononucleotides and Casein by Lanthanum and Cerium Hydroxide Gels

Abstract 1. The dephospkorylation reaction of RNA by lanthanum hydroxide gel was further studied. The activation energy of the reaction is 20,200∼20,400 cal. Optimal pH is between 8 and 9. 2. RNA is hydrolysed almost completely into nucleosides and inorganic phosphate at 90° in 40 hours at pH 8. The formation of nucleosides as the final product of hydrolysis was shown from the reducing power measurements and periodate consumption of products. 3. DNA is not dephosphorylated at all under conditions where RNA is almost completely dephosphorylated. This may be related to the structural difference of DNA and RNA. 4. Preparative method for ribonucleosides from RNA under catalytic effect of lanthanum hydroxide was described. Ribonucleosides are obtained in good yields. 5. Desoxyribo-, a-ribo-, b-ribo-, and 5′-ribocytidylic acid are all subject to catalytic dephosphorylation. 5′-Ribocytidylic acid is dephosphorylated most slowly. 6. Cerium hydroxide can be used as catalyst of the reaction in the same way with lanthanum hydroxide. 7. The dephosphorylation of casein is considerably accelerated by lanthanum hydroxide at 70° but not at 25°.