Abstract
The presence of high ADP hydrolysis activity in Mimosa pudica was previously reported. However, biochemical characteristics of the enzyme were not studied in detail. In the present study, we purified ADP hydrolysis enzyme (ADPase) from Mimosa plant by sequential column chromatography. The purified ADPase was detected as smear bands on SDS-PAGE gels with relative molecular masses of 67 kDa, indicating that some isoforms of ADPase resulted from the post-translational modification such as glycosylation. The determined partial amino acid sequences of the peptides showed similarity with other plant apyrases. Inhibition of NTP/NDP hydrolysis activity with triflupromazine (TFP) indicates that Mimosa ADPase belongs to the ecto-apyrase group. The ratio of the rate of ATPase/ADPase of apyrases from the other plants range from 0.7 to 1.5, whereas the ratio of the Mimosa ADPase is more than 4. Thus, Mimosa ADPase is a novel enzyme. I plan to elucidate a physiologic functions in detail.
