The changes in peroxidase activity and its isozyme pattern in the different parts of mung bean sprout were investigated: The enzyme activity in cotyledon and root showed a tendency to increase at an early stage and then decreased gradually as germination continued. However, the crude homogenate of epicotyl and hypocotyl showed a continuous decline in the enzyme activity. In particular, the enzyme activity of the root was 1.5∼3.5 times higher than that of other parts.
Gel electrophoresis of the crude homogenate revealed that the number of isozyme in every part of the mung bean sprout increase during germination up to 6th days.
Two isozymes from root were partially purified by ammonium sulfate fractionation, gel filtration by Sephadex G-75 and DEAE-cellulose column chromatography. One of the isozymes (A) was purified 16-fold by the present procedure, but the purity of the other isozyme (B) was not increased, significantly.
Isozyme A was the most active at 65℃ and isozyme B at 70℃, while both isozyme (A, B) have a optimal pH of 5.6. The Km values of isozyme A and B for 0-dianisidine as a hydrogen donor determined to be 0.071 mM and 0.052 mM, respectively, and those for isozyme A and B using H₂O₂ as a hydrogen acceptor were 0.28 mM and 0.23 mM, respectively.
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