Enhancing the separation of phosphorylated proteins in gel electrophoresis with dinuclear bispyridylmethylamine–tyrosine–acrylamide complexes

Bispyridylmethylamine–tyrosine–acrylamide ligands were prepared from protected tyrosine and dipyridylmethylamine by a twofold Mannich reaction and converted into acryl amides. Their manganese complexes were used as gel additives to increase the specific phosphate affinity in SDS–PAGE protein separations. The modified gel showed a distinct mobility shift of phosphorylated α-casein in comparison to the dephosphorylated protein.