Table III.

Substrate specificity for selected peroxidase isoforms

Plant Source	Isoform	Substrate					Reference
		p-Coumarate 1a	Caffeate 2a	Ferulate 3a	Sinapate 4a	Coniferyl Alcohol 6a
Cationic peroxidases
Potato		4.9	33	100	12	105	Present work
Horseradish	IX	121	NAa	100	1.7	NA	Takahama (1995)
V. myrtillus	C1	14	64	100	NA	150	Melo et al. (1997)
	C2	61	69	100	NA	128	Melo et al. (1997)
Soybean	Leaf	NA	174	100	NA	NA	Schmitz et al. (1997)
	Stem	NA	466	100	NA	NA	Schmitz et al. (1997)
Anionic peroxidases
Potato		3.1	53	100	11	57	Present work
Horseradish	VII	44	NA	100	3.6	NA	Takahama (1995)
	VIII	18	NA	100	6.6	NA	Takahama (1995)
	VIII	6.3	64	100	5.1	64	Present work
Soybean	Leaf-1	NA	160	100	NA	NA	Schmitz et al. (1997)
	Leaf-2	NA	0b	100	NA	NA	Schmitz et al. (1997)
	Stem	NA	0	100	NA	NA	Schmitz et al. (1997)

Values represent relative rates of oxidation of the substrates listed, with ferulic acids arbitrarily set to 100%. Isoforms are grouped as either cationic or anionic.

^aNA, Data not available. 

^b0, No measurable activity.