Exploring the potential of 3′-O-carboxy esters of thymidine as inhibitors of ribonuclease A and angiogenin

Abstract

In this study, compounds with a carboxy ester in lieu of the phosphate ester at the 3′-position have been employed to inhibit the ribonucleolytic activity of ribonuclease A (RNase A). Phosphates at the 3′-position of pyrimidine bases are well-known inhibitors of the protein. We have investigated the inhibition of RNase A by 3′-O-carboxy esters of thymidine. The compounds behave as competitive inhibitors with inhibition constants ranging from 42 to 95 μM. The mode of inhibition has also been confirmed by ¹H NMR studies of the active site histidines of RNase A. Docking studies have further substantiated the experimental results. The compounds are also found to inhibit the ribonucleolytic activity of angiogenin, a homologous protein and potent inducer of blood vessel formation.