Table I.

Distribution of marker enzyme activities in a Mg²⁺ and a subsequent EDTA gradient

Enzyme	Specific Activitya								Ratio of B/EDTA:C/Mg2+
	A/Mg2+	B/Mg2+	C/Mg2+	D/Mg2+	A/EDTA	B/EDTA	C/EDTA	D/EDTA
	nkat mg−1 protein
NADH-Cyt c-reductaseb	0.69	0.12	0.46	1.19	0.13	0.68	0.48	0.45	1.48
Succinate dehydrogenasec	16.14	7.22	15.99	160.60	0.80	5.93	31.10	51.91	0.37
VO43−-inhibited ATPased	0.17	0.43	2.22	2.19	0.08	0.76	1.05	2.19	0.34
NO3−-inhibited ATPasee	0.22	0.22	0.48	0.27	0.14	0.47	0.34	0.27	0.98

Shown are the mean values of three gradients.

^aDensity zones: A, 1.059 to 1.077 g cm⁻³ (15%–19% Suc); B, 1.085 to 1.127 g cm⁻³ (21%–30% Suc); C, 1.132 to 1.176 g cm⁻³ (31%–40% Suc); and D, 1.182 to 1.224 g cm⁻³ (41%–49% Suc). 

^bAntimycin A-insensitive ER marker enzyme. 

^cMitochondrial marker enzyme. 

^dPlasma membrane marker enzyme. 

^eTonoplast marker enzyme.