The direct effect of phosphorylation at serines 22 and 23 is a local rearrangement in which basic amino acids, including neighbouring arginines in NcTnI (Arg19, 21 and 26) and cTnC lysine 39 tend to form a cluster of ionic bonds with the phosphate groups of phosphoserines 22 and 23 at the expense of interactions between cTnI and cTnC, particularly the cTnC Asp33 interaction with Arg19, 20 and 21 of NcTnI.