A New Variant of Emissive RNA Alphabets
Paul T. Ludford, Shenghua Yang, Marcela S. Bucardo, Yitzhak Tor
Abstract
Abstract A new fluorescent ribonucleoside alphabet ( mth N) consisting of pyrimidine and purine analogues, all derived from methylthieno[3,4‐ d ]pyrimidine as the heterocyclic core, is described. Large bathochromic shifts and high microenvironmental susceptibility of their emission relative to previous alphabets derived from thieno[3,4‐ d ]pyrimidine ( th N) and isothiazole[4,3‐ d ]pyrimidine ( tz N) scaffolds are observed. Subjecting the purine analogues to adenosine deaminase, guanine deaminase and T7 RNA polymerase indicate that, while varying, all but one enzyme tolerate the corresponding mth N/ mth NTP substrates. The robust emission quantum yields, high photophysical responsiveness and enzymatic accommodation suggest that the mth N alphabet is a biophysically viable tool and can be used to probe the tolerance of nucleoside/tide‐processing enzymes to structural perturbations of their substrates.