Interaction of beta-L-adenosine-5 '-triphosphate (L-ATP) with human deoxycytidine kinase, human DNA primase and T4 DNA ligase: Does the chance directenzymatic enantioselectivity?

We demonstrate that L-ATP: 1) as well as its natural D-enantiomer, acts as a phosphate donor in the reaction catalysed by human deoxycytidine kinase; 2) inhibits human DNA-primase and the ATP-dependent T4 DNA ligase. Thus, th e lack of enantioselectivity of the enzymes is more frequent than it was be lieved a few years ago and we suggest that it would depend on chance more t han on an evolutionary strategy.