Thermodynamics of 7-methylguanosine cation stacking with tryptophan upon mRNA 5' cap binding to translation factor eIF4E

All eukaryotic nuclear transcribed mRNAs possess the cap structure, consisting of 7-methylguanosine linked by the 5'-5' triphosphate bridge to the first nucleoside. The goal of the present study is to dissect the enthalpy and entropy changes of association of the mRNA 5' cap with eIF4E into contributions originating from the interaction of 7-methylguanosine with tryptophan. The model results are discussed in the context of the thermodynamic parameters for the association of eIF4E with synthetic cap analogues.