title: [Interconvertibility of molecular forms of 3'5' cyclic AMP phosphodiesterase of human platelets].
abstract: Three forms of cyclic AMP phosphodiesterase from human platelets are resolved upon sucrose gradient centrifugation : 2.5S (monomer), 4.8S (dimer) and 7S (tetramer). They are interconvertible and form an association-dissociation equilibrium depending on the concentration of enzyme. The dissociated form has a high Km for cyclic AMP (Km : 3-5.10(-4) M) whereas the associated form has a low Km (Km : 3-5.10(-5) M).
mesh_terms: D015105:3',5'-Cyclic-AMP Phosphodiesterases; D001792:Blood Platelets / Q000201:enzymology*; D002499:Centrifugation, Density Gradient; D006801:Humans; D007700:Kinetics; D008970:Molecular Weight; D010727:Phosphoric Diester Hydrolases; D011487:Protein Conformation; D013329:Structure-Activity Relationship; D013696:Temperature
chemical_list: D010727:Phosphoric Diester Hydrolases; D015105:3',5'-Cyclic-AMP Phosphodiesterases
vernacular_title: Interconvertibilité des formes moléculaires de l'AMP 3'-5' cyclique phosphodiestérase des plaquettes humaines