Analysis of the major polypeptides of spectrin by tryptic digestion.
The two major polypeptides of erythrocyte membrane spectrin have been isolated by preparative polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulfate. The tryptic peptide maps of the two polypeptides have been prepared by thin-layer chromatography and electrophoresis. Radioactive peptides have been prepared by 14C-carboxymethylation and chloramine T-catalysed 125I iodination. Maps of both sets of peptides demonstrate a marked similarity between the two parent polypeptides.