The identification and partial purification of the actin-binding domain of human erythrocyte spectrin

he junctions of the red blood cell membrane cystoskeleton are formed by interactions between spectrin and actin protofilaments. A spectrin tryptic peptide of 16.5 kDa apparent molecular weight which binds specifically to actin in co-sedimentation experiments has been identified. Partial purification of the functional peptide has been achieved using gel filtration on Sepharose 4B followed by both anion (DE52) and cation (CM52) exchange chromatography. Comparison of the two-dimensional iodopeptide maps of the peptide with those of the spectrin...