7.3.2.1	K+	stimulates 5fold	698749	
7.3.2.1	Mg2+	-	669115, 669126, 670171, 670533	
7.3.2.1	additional information	no activation with Ca2+, Mg2+	659162	
7.3.2.1	Na+	25 mM	711256	
7.3.2.1	Na+	required only at pH higher than 5.5, stimulates 15fold	698749