title: Dictyostelium calmodulin: affinity isolation and characterization.
abstract: The Ca2+-binding regulatory protein calmodulin (CaM) has been purified from the cellular slime mold, Dictyostelium discoideum. Isolation of homogeneous Dictyostelium CaM was accomplished in high yield by ion-exchange chromatography and Ca2+-dependent affinity chromatography on phenothiazine-Sepharose 4B. This isolate has been demonstrated to possess the following physicochemical and functional properties characteristic of other CaM isolates: (i) a molecular weight ca. 16,000; (ii) an amino acid composition similar to other CaMs--with the notable exception that Dictyostelium CaM, as first determined by Bazari and Clarke [(1981) J. Biol. Chem. 256, 3598-3603] lacks the single trimethylated lysine (Tml) residue identified in nearly all CaMs purified to date; (iii) a CNBr peptide map similar to that of other CaMs; (iv) a Ca2+-dependent shift in migration during native- and sodium dodecyl sulfate-polyacrylamide gel electrophoretic analyses; (v) ability to form Ca2+-dependent complexes with rabbit skeletal muscle troponin I; and (vi) ability to activate in a Ca2+-dependent manner bovine brain cyclic nucleotide phosphodiesterase.
mesh_terms: D000596:Amino Acids / Q000302:isolation & purification; D000818:Animals; D001921:Brain / Q000201:enzymology; D002147:Calmodulin / Q000302:isolation & purification* / Q000378:metabolism; D002417:Cattle; D055598:Chemical Phenomena; D002621:Chemistry; D002846:Chromatography, Affinity; D004023:Dictyostelium / Q000032:analysis*; D004591:Electrophoresis, Polyacrylamide Gel; D004789:Enzyme Activation; D011485:Protein Binding; D011817:Rabbits
chemical_list: D000596:Amino Acids; D002147:Calmodulin