Biochemical characteristics of a calmodulin-phosphodiesterase activator increased in spontaneously hypertensive mice and rats.
The biochemical characteristics of calmodulin-phosphodiesterase (CaM-PDE) are described. It is a cytosolic, hydrophobic, and heat-, acid-, and base-stable compound sensitive to proteases. It is optimally extracted from neutral supernatants by CHCl3/MeOH (2:1 or 1:1). It partitions into the organic fraction of CHCl3/MeOH extracts, whereas the aqueous fraction contains a component that potentiates the activator's capacity to stimulate CaM-PDE. The activator interacts with PDE by increasing its apparent affinity for CaM. Size partition chromatography of CHCl3/MeOH extracts from spontaneously hypertensive rats produces two activity peaks, one eluting at void volume with the second eluting at a position corresponding to a 4-kDa peptide. The compound at void volume can be converted to the 4-kDa entity by sonication. The CaM-PDE activator behaves as a lipopeptide that shares several characteristics with parathyroid hypertensive factor.
Chang
E
E
Centre de Recherche Hôtel-Dieu de Montréal, Université de Montréal, Québec, Canada.
Hamet
P
P
Tremblay
J
J
D000136:Acid-Base Equilibrium / Q000187:drug effects; D000818:Animals; D002147:Calmodulin / Q000378:metabolism*; D002846:Chromatography, Affinity; D002850:Chromatography, Gel; D002918:Chymotrypsin; D004789:Enzyme Activation; D006321:Heart / Q000502:physiology; D006863:Hydrogen-Ion Concentration; D006868:Hydrolysis; D006973:Hypertension / Q000097:blood / Q000378:metabolism* / Q000503:physiopathology; D051379:Mice; D009206:Myocardium / Q000378:metabolism; D010727:Phosphoric Diester Hydrolases / Q000378:metabolism*; D051381:Rats; D011918:Rats, Inbred SHR; D011921:Rats, Inbred WKY; D014020:Tissue Extracts / Q000494:pharmacology; D014357:Trypsin
D002147:Calmodulin; D014020:Tissue Extracts; D010727:Phosphoric Diester Hydrolases; D002918:Chymotrypsin; D014357:Trypsin