title: Amino acid sequence of P-57, a neurospecific calmodulin-binding protein.
abstract: The amino acid sequence was determined for bovine brain P-57, a neurospecific, membrane-associated, calmodulin-binding protein. It consists of a single 239-residue polypeptide chain blocked at its amino terminus and containing an unusually hydrophilic amino acid composition. Seventy percent of the molecule is composed of Glu/Gln, Ala, Lys, Asp/Asn, and Pro; there is only one aromatic residue. A lack of favorable cleavage sites required that a particularly wide variety of digests and subdigests be performed to obtain appropriate sets of overlapping peptides. This protein is clearly homologous with the cDNA-derived sequence of mouse brain P-57, although the bovine protein is 12 amino acid residues longer; the homology is less obvious in the middle sections of the two sequences. Bovine brain P-57 lacks homology with any other protein in an updated sequence database. A segment reported to interact with calmodulin (Arg-Gly-His-Ile-Thr-Arg-Lys-Lys-Leu) is placed at residues 43-51 within the only extended segment of P-57 that carries the net positive charge that would favor that interaction. There is no hydrophobic segment characteristic of many proteins that interact with membranes.
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001923:Brain Chemistry; D002148:Calmodulin-Binding Proteins; D002417:Cattle; D019922:GAP-43 Protein; D051379:Mice; D008969:Molecular Sequence Data; D009419:Nerve Tissue Proteins; D010446:Peptide Fragments / Q000032:analysis; D010447:Peptide Hydrolases; D013045:Species Specificity
chemical_list: D002148:Calmodulin-Binding Proteins; D019922:GAP-43 Protein; D009419:Nerve Tissue Proteins; D010446:Peptide Fragments; D010447:Peptide Hydrolases