An alternative method for a fast separation of phosphotyrosine.

A simple and rapid procedure is described for fully separating phosphotyrosine from phosphoserine and phosphothreonine through one-dimensional thin-layer chromatography. The migration properties of these phosphoamino acids are compared with those of CMP, UMP, ATP, ribose phosphate, and inorganic orthophosphate, considered the most frequent comigrating products derived from 32P-labeling experiments. We demonstrate that Rf values for the three phosphoamino acids differ from those displayed by the mentioned contaminating compounds. One of the most relevant advantages of this procedure is that a complete separation of phosphotyrosine can be achieved in only 90 min.