TABLE 2.

Effect of different monovalent and divalent cations on alginate lyase activity assay^a

Cation added	Alginate lyase activity (A548)
None	0.010
K+	0.173
Na+	0.014
Mg2+	0.017
K+ plus Mg2+	0.927
Mg2+ plus Na+	0.018
K+ plus Mg2+ plus Na+	1.059

^aAliquots of a purified A. chroococcum alginate lyase preparation (30 mU) were assayed for enzyme activity in the presence of the indicated cations at 100 mM (final concentration) each. Other experimental conditions were as in the thiobarbituric acid assay, except that 10 mM Tris-HCl buffer (pH 7.5) was used.