TABLE 2.

Comparison of the four KTBA-oxidizing peroxidases isolated from liquid cultures (peroxidases PL1 and PL2) and SSF cultures (peroxidases PS1 and PS3) of P. eryngii: enzymatic activities, KTBA oxidation, and degradation of β-O-4 dimers (effects of Mn²⁺ and veratryl alcohol)

Peroxidase	Enzymatic activities (U/mg) ona:			Ethylene release (μmol/mg)b			% Dimer transformationc
							Phenolic dimer		Nonphenolic dimer
	Mn2+	DMP	Veratryl alcohol	Direct	Veratryl alcohol	Mn2+	Direct	Mn2+	Direct	Veratryl alcohol
PL2	125	44	10	0	54	22	65	100	19	19
PL1	109	57	14	0	52	26	+d	+	+	+
PS1	174	38	3	0	30	29	0	100	0	0
PS3	356	65	0	0	0	88	0	100	0	0

^aOxidation of 0.1 mM Mn²⁺ was determined at pH 5, and oxidation of 10 mM DMP or 10 mM veratryl alcohol was determined at pH 3. 

^bEthylene concentration resulting from KTBA oxidation in the presence of 1 mM veratryl alcohol or 3 mM Mn²⁺. 

^cLevel of transformation of 0.25 mM phenolic dimer (pH 4.5; 0.5 U/liter; estimated on the basis of Mn²⁺ oxidation) and nonphenolic dimer (pH 3.5; 0.5 U/liter estimated on the basis of veratryl alcohol oxidation) after 70 min. 

^d+, Peroxidase PL1, an allelic variant of peroxidase PL2, has degradation abilities with model dimers similar to those of peroxidase PL2 (the transformation rates were not calculated).