Analysis of Nickel-Binding Peptides in a Human Hepidermoid Cancer Cell Line by Ni-NTA Affinity Chromatography and Mass Spectrometry

To elucidate whether eukaryotic elongation factor 1A (eEF-1A) in a human hepidermoid cancer cell line (H1355) belonged to the family of the Ni-interacting protein, we analyzed the sequence of peptides obtained by on-Ni- NTA-agarose tryptic digestion of proteins from H1355 cell extract. LC/MS analysis showed the presence of several peptides mainly from abundant cellular proteins corresponding to eEF-1A, tubulin and actin. The results indicated that F-actin strongly binds to Ni-NTA-agarose whereas the other proteins are indirectly bound to the resin because of the formation of a protein-protein complex with actin.