Article Document Academic Article Information Content Entity Continuant Continuant Journal Article Entity Entity Generically Dependent Continuant 2025-05-08T08:53:19 RDF description of Stimulation of guanylate cyclase by EDTA and other chelating agents - http://repository.healthpartners.com/individual/document-rn20396 Comparative Studies public 27960 658 2022-02-21T22:48:57.408-06:00 <p>The partially purified soluble guanylate cyclase (GTP pyrophosphatelyase(cyclizing), EC 4.6.1.2) from human caudate nucleus is stimulated from 2 to 4-fold by metal chelating agents. EDTA (K 1/2 - 4.8 microM) is more potent than CDTA (K 1/2 = 13.2 microM) or EGTA (K 1/2 = 21.8 microM) at stimulating activity. Stimulation by chelating agents is apparently not due to removal of inhibitory divalent cations which contaminate the enzyme or reaction mixture. EDTA increases guanylate cyclase activity in part by increasing the affinity of the enzyme for the substrate (MgGTP) 10-fold. Dopamine inhibits partially purified guanylate cyclase in the presence or absence of EDTA. Dopamine increases the Ka of guanylate cyclase for the activator, free Mn2+, more than 50-fold, from 3 to 150 microM.<p> 16720 document-rn20396 Drugs and Drug Therapy Biochimica et Biophysica Acta 10.1016/0005-2744(81)90307-7 2 Stimulation of guanylate cyclase by EDTA and other chelating agents