Lung phosphodiesterase isoenzymes.
The distinct phosphodiesterase isoenzyme activities in guinea-pig lung were identified and characterised. We demonstrate that protein kinase A catalyses the activation of lung Type V cyclic GMP phosphodiesterase. This occurs via a marked change in the Vmax for cyclic GMP hydrolysis. The sensitivity of the activated PDE to inhibition by zaprinast is also markedly reduced (zaprinast inhibits in PDE activity via a mixed mechanism). We suggest that activation of the PDE by protein kinase A involves a mechanism that leads to alteration in the regulatory action of a non-catalytic cyclic GMP binding site.
Department of Physiology and Pharmacology, University of Strathclyde, Glasgow, UK.
N J
NJ
Pyne
F
F
Burns
D015106:3',5'-Cyclic-GMP Phosphodiesterases / Q000037:antagonists & inhibitors; D000818:Animals; D002384:Catalysis; D004789:Enzyme Activation; D006168:Guinea Pigs; D007527:Isoenzymes / Q000032:analysis*; D008168:Lung / Q000201:enzymology*; D009130:Muscle, Smooth / Q000187:drug effects; D010477:Perfusion; D010727:Phosphoric Diester Hydrolases / Q000032:analysis*; D011688:Purinones / Q000494:pharmacology; D011719:Pyrazines / Q000494:pharmacology
D007527:Isoenzymes; D011688:Purinones; D011719:Pyrazines; C048350:5-(4-acetamidophenyl)pyrazin-2(1H)-one; D010727:Phosphoric Diester Hydrolases; D015106:3',5'-Cyclic-GMP Phosphodiesterases; C011145:zaprinast