title: Nucleoside diphosphate kinase from human erythrocytes. Structural characterization of the two polypeptide chains responsible for heterogeneity of the hexameric enzyme.
abstract: Human erythrocyte nucleoside-diphosphate kinase (NDP kinase) is a hexameric enzyme consisting of two kinds of polypeptide chains, A and B. By random association (A6, A5B...AB5, B6) these polypeptides form isoenzymes differing in their isoelectric point. Chains A and B of NDP kinase were purified by ion-exchange chromatography under denaturing conditions. Upon mixing and renaturation, the isozymic pattern of NDP kinase obtained by conventional methods was restored. Antibodies raised against purified chains showed significant cross-reactivity, both in immunoblot experiments and activity inhibition studies. Sequence determination showed that both chains consisted of 152 amino acid residues corresponding to Mr or 17,143 (chain A) and 17,294 (chain B), respectively. There was high homology between the two sequences (88% identity). The phosphorylation site on the enzyme is located at His-118. Chain A was identical with human Nm23 protein, which has been reported as a potential suppressor protein in tumor metastasis and chain B was identical with Nm23-H2 protein.
authors.affiliation: Unité de Biochimie des Régulations Cellulaires, Institut Pasteur, France.
authors.forename: A M
authors.initials: AM
authors.lastname: Gilles
authors.forename: E
authors.initials: E
authors.lastname: Presecan
authors.forename: A
authors.initials: A
authors.lastname: Vonica
authors.forename: I
authors.initials: I
authors.lastname: Lascu
mesh_terms: D000595:Amino Acid Sequence; D015153:Blotting, Western; D004912:Erythrocytes / Q000201:enzymology*; D006801:Humans; D046911:Macromolecular Substances; D008969:Molecular Sequence Data; D009701:Nucleoside-Diphosphate Kinase / Q000097:blood* / Q000737:chemistry / Q000276:immunology; D010449:Peptide Mapping; D010766:Phosphorylation; D013045:Species Specificity; D013329:Structure-Activity Relationship
chemical_list: D046911:Macromolecular Substances; D009701:Nucleoside-Diphosphate Kinase