[Study of the substrate specificity of T4 RNA ligase: interaction of the enzyme with ATP analogs modified through the ribose residue and with affinity sorbents].

To elucidate the role of the ribose moiety in substrate binding, various ATP derivatives modified in ribose moiety were studied as probes for the T4 RNA ligase first stage reaction. The kinetic parameters for competitive inhibition were determined. Inhibition experiments using substrate analogs demonstrated that the major binding determinants of ATP analogs were purine and triphosphate moieties of ATP; modification of the ribose moiety was not critical. Adenosine triphosphates attached to agarose were used as affinity adsorbent for purification of T4 RNA ligase. These derivatives had been successfully used in reversible binding of the enzyme. Best results were achieved with agarose coupled via N6 of the purine moiety of ATP.