title: The cyclic nucleotide phosphodiesterase inhibitory protein of Dictyostelium discoideum. Purification and characterization.
abstract: We have purified the glycoprotein inhibitor of the extracellular cyclic nucleotide phosphodiesterase of Dictyostelium discoideum to apparent homogeneity. The inhibitor has a molecular weight of 47,000 measured by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The interaction of the inhibitor and the cyclic nucleotide phosphodiesterase occurs with 1:1 stoichiometry and with a dissociation constant of about 10(-10) M. Periodate oxidation of the inhibitor or of the enzyme destroys concanavalin A binding ability but does not affect the formation of the enzyme-inhibitor complex. Inhibitor is not produced by cells during logarithmic growth but appears in quantity during stationary phase and after transfer from growth medium to phosphate buffer.
mesh_terms: D015105:3',5'-Cyclic-AMP Phosphodiesterases / Q000302:isolation & purification / Q000378:metabolism*; D000596:Amino Acids / Q000032:analysis; D002241:Carbohydrates / Q000032:analysis; D003208:Concanavalin A / Q000494:pharmacology; D004023:Dictyostelium / Q000201:enzymology* / Q000254:growth & development; D007700:Kinetics; D008970:Molecular Weight; D010504:Periodic Acid / Q000494:pharmacology
chemical_list: D000596:Amino Acids; D002241:Carbohydrates; D010504:Periodic Acid; D003208:Concanavalin A; D015105:3',5'-Cyclic-AMP Phosphodiesterases