3.1.4.17	Ba2+	40% stimulation at 0.25 mM	135213	
3.1.4.17	Ca2+	-	135233, 135234, 135235, 135236	
3.1.4.17	Ca2+	40% stimulation at 0.25 mM	135213	
3.1.4.17	Ca2+	activates in vivo	715153	
3.1.4.17	Ca2+	Ca2+ activates	692191	
3.1.4.17	Ca2+	Ca2+/calmodulin dependent	135214, 135265, 135266, 135274	
3.1.4.17	Ca2+	Ca2+/calmodulin stimulated	135217, 135218, 135240, 135268	
3.1.4.17	Ca2+	Ca2+/calmodulin-dependent enzyme	667909	
3.1.4.17	Ca2+	differential effect on isozymes, activation only in complex with calimodulin, overeview	651468	
3.1.4.17	Ca2+	isoform PDE1B2 activity can be regulated by changes in Ca2+ levels	682531	
3.1.4.17	Ca2+	stimulation of phosphodiesterase II	135279	
3.1.4.17	CaCl2	entirely dependent on the presence of divalent cations, activity with 0.2 mM CaCl2 is 15.9% of maximal activity obtained with 2 mM MgCl2	668560	
3.1.4.17	Co2+	2 mM, 212% of initial activity	728995	
3.1.4.17	Co2+	activates	750557	
3.1.4.17	Co2+	activates isoform PdeB	750557	
3.1.4.17	Co2+	can substitute for Mg2+	135228	
3.1.4.17	Co2+	required, activates	715378	
3.1.4.17	Co2+	stimulates	135225	
3.1.4.17	Co2+	stimulates at 2.5 mM	135213	
3.1.4.17	Co2+	the enzyme activities of PdeA and PdeB in the hydrolysis of 3',5'-cAMP are stimulated 3.2fold and 1.98fold at pH 8.0 in 50 mM Tris-HCl buffer by the addition of Co2+ at 0.05 mM, respectively	692369	
3.1.4.17	Cu2+	stimulates at 2.5 mM	135232	
3.1.4.17	Fe2+	activates	750557	
3.1.4.17	Fe2+	required	750557	
3.1.4.17	Fe3+	-	681407	
3.1.4.17	Fe3+	2 mM, 121% of initial activity	728995	
3.1.4.17	Fe3+	activates	750557	
3.1.4.17	Fe3+	required	653848, 750557	
3.1.4.17	Mg2+	activates	750557	
3.1.4.17	Mg2+	dependent on	135228, 135235	
3.1.4.17	Mg2+	entirely dependent on the presence of divalent cations, maximal activity with 2 mM MgCl2	668560	
3.1.4.17	Mg2+	is coordinated to Asp564, two phosphate oxygen atoms, and three water molecules	716015	
3.1.4.17	Mg2+	required	135219, 135254	
3.1.4.17	Mg2+	stimulates	135225, 135235	
3.1.4.17	Mg2+	stimulates at 2.5 mM	135213	
3.1.4.17	Mn2+	-	681407	
3.1.4.17	Mn2+	activates	750557	
3.1.4.17	Mn2+	activates isoforms PdeA and PdeB	750557	
3.1.4.17	Mn2+	can substitute for Mg2+	135228	
3.1.4.17	Mn2+	entirely dependent on the presence of divalent cations, activity with 2 mM MnCl2 is 53.5% of maximal activity obtained with 2 mM MgCl2	668560	
3.1.4.17	Mn2+	Km value and Hill constant for wild-type 0.021 mM and 1, respectively, for mutant D21A 0.021 mM and 4.1, respectively, for mutant H23A 0.053 mM and 1, respectively, for mutant D66A, 0.072 and 6.4, respectively, for mutant H169A 0.022 and 1.7, respectively, for mutant H207A, 0.062 and 3.1, respectively	667641	
3.1.4.17	Mn2+	required	135219	
3.1.4.17	Mn2+	required, activates	715378	
3.1.4.17	Mn2+	stimulates	135225	
3.1.4.17	Mn2+	stimulates at 2.5 mM	135213	
3.1.4.17	Mn2+	the enzyme activities of PdeA and PdeB in the hydrolysis of 3',5'-cAMP are stimulated 4fold and 2.14fold at pH 8.0 in 50 mM Tris-HCl buffer by the addition of Mn2+ at 0.05 mM, respectively	692369	
3.1.4.17	additional information	-	135230	
3.1.4.17	additional information	no effect on enzyme activity by Mg2+	715378	
3.1.4.17	additional information	no metal ion required	135213, 135232	
3.1.4.17	additional information	no metal ion requirement	654017	
3.1.4.17	additional information	requires a divalent metal ion	653848	
3.1.4.17	Zn2+	contains 2.8 zinc atoms per molecule of purified enzyme	751582	
3.1.4.17	Zn2+	entirely dependent on the presence of divalent cations, activity with 0.03 mM ZnCl2 is 19.5% of maximal activity obtained with 2 mM MgCl2	668560	
3.1.4.17	Zn2+	is coordinated to His529, His563, Asp564, Asp674, and two phosphate oxygen atoms	716015