Electrophoretic pattern of purified perMn-SOD and mitMn-SOD from watermelon cotyledons in native gels. 1, Purified perMn-SOD (1 μg); 2, partially purified mitMn-SOD (1 μg); 3, purified perMn-SOD (80 μg); 4, whole peroxisomes from watermelon cotyledons (50 μg); 5, peroxisomal membranes from watermelon cotyledons (25 μg); 6, mitochondria from watermelon cotyledons (50 μg); 7, partially purified mitMn-SOD (10 μg). Subcellular fractions from watermelon cotyledons were purified as indicated in the Materials and methods. A 1:1000 dilution of the antibody against pea leaf Mn-SOD was used.