title: Inability of parvalbumin to function as a calcium-dependent activator of cyclic nucleotide phosphodiesterase activity.
abstract: The calcium-sensitive phosphodiesterase-stimulating activity sometimes associated with parvalbumin preparations is due to contaminating (less than 0.1%) amounts of carp muscle CDR (calcium-dependent regulator)-like protein. This protein can be resolved from parvalbumins by Sephadex G-75 chromatography and has many characteristics of the CDR. Parvalbumin itself causes a nonspecific stimulation of phosphodiesterase at all calcium concentrations which, in the presence of CDR, can cause an apparent shift to a lower concentration of the calcium level required for half-maximal stimulation.
mesh_terms: D015105:3',5'-Cyclic-AMP Phosphodiesterases / Q000378:metabolism*; D000818:Animals; D002118:Calcium / Q000494:pharmacology*; D002347:Carps; D004789:Enzyme Activation; D009124:Muscle Proteins / Q000302:isolation & purification / Q000502:physiology*; D009132:Muscles / Q000378:metabolism; D010320:Parvalbumins / Q000302:isolation & purification / Q000502:physiology*
chemical_list: D009124:Muscle Proteins; D010320:Parvalbumins; D015105:3',5'-Cyclic-AMP Phosphodiesterases; D002118:Calcium