title: Identification of the functional site of erythrocyte protein 4.1 involved in spectrin-actin associations.
abstract: Peptides produced by mild chymotryptic digestion of human erythrocyte protein 4.1 mimic the ability of intact 4.1 to promote the binding of spectrin to F-actin. This complex-promoting activity was found to reside in an 8-kDa peptide which was fully functional when dissociated from other protein 4.1-derived peptides, indicating that noncovalent complexes of multiple peptides were not essential for activity. The 8-kDa peptide was incorporated into a ternary complex with spectrin and F-actin in approximately stoichiometric amounts. Amino acid composition and two-dimensional peptide mapping show that the 8-kDa active peptide is located within the 10-kDa region of protein 4.1 which contains a cAMP-dependent phosphorylated site.
mesh_terms: D000199:Actins / Q000378:metabolism*; D000596:Amino Acids / Q000032:analysis; D001665:Binding Sites; D001798:Blood Proteins / Q000032:analysis*; D002851:Chromatography, High Pressure Liquid; D002918:Chymotrypsin / Q000378:metabolism; D003598:Cytoskeletal Proteins; D006801:Humans; D008565:Membrane Proteins; D008970:Molecular Weight; D009479:Neuropeptides; D010446:Peptide Fragments / Q000032:analysis / Q000378:metabolism; D013049:Spectrin / Q000378:metabolism*; D014357:Trypsin / Q000378:metabolism
chemical_list: D000199:Actins; D000596:Amino Acids; D001798:Blood Proteins; D003598:Cytoskeletal Proteins; D008565:Membrane Proteins; D009479:Neuropeptides; D010446:Peptide Fragments; C028841:erythrocyte membrane band 4.1 protein; C120557:erythrocyte membrane protein band 4.1-like 1; D013049:Spectrin; D002918:Chymotrypsin; D014357:Trypsin