There is H-bond interactions between the CcTnT Lys280 and the phosphorylated Ser22 and 23 of NcTnI which are completely absent in the unphosphorylated state (Figure ). There is also an increased cumulative ionic interaction between cTnI Arg19, 20 and 21 and CcTnT Lys280 and 288 upon phosphorylation which like the interaction with the Ser22 and 23 is absent in the unphosphorylated state (Figure ). the helix. This is reflected in the reduction of its interactions with Glu95, Glu96 and Leu97. The overall effect is that the cTnC linker peptide lengthens upon phosphorylation increasing the distance between the NcTnC and CcTnC domains (Figure ). The increased distance is quantified in Table and Supplementary