Breast cancer protein StarD10 identified by three-dimensional separation using free-flow electrophoresis, reversed-phase high-performance liquid chromatography, and sodium dodecyl sulfate-polyacrylamide gel electrophoresis

Abstract

A 35 kDa protein present in mammary tumors from Neu/ErbB2 transgenic mice was detected on the basis of its cross-reactivity with a phosphoserine-specific antibody against the transcription factor FKHR. To isolate this protein from cytosolic extracts derived from human breast carcinoma cells, we used free-flow electrophoresis in the first dimension to separate proteins according to their charge, followed by reversed-phase high-performance liquid chromatography (RP-HPLC) in the second and sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) in the third dimension. Tryptic digests of Coomassie-stained bands were analyzed by nano-spray ionization-quadrupole quadrupole-time of fli..