Determination of 5'-Nucleotidase Activity of Higher Plants by Using an Improved Method
The presence of relatively high non-specific phosphatase activities are known in various plant tissues. These enzymes also catalyze the removal of inorganic phosphate from nucleoside monophosphates. According to published reports, so far, the experimental investigations, concerning the 5'-nucleotidase activity, have been mostly carried out without consideration of the non-specific phosphatase activities in crude enzymic extracts. However, few researchers have been included some inhibitors of these phosphatases, such as NaMoO 4 or KF, in assay mixtures. But phosphatases are not completely inhibited by these inhibitors and, therefore, interfere the activity of 5'-nucleotidase. Thus, the non-specific phosphatase activities were determined in crude enzymic extracts by using p-nitro-phenyl phosphate as substrate and the apparent 5'-nucleotidase activity was, first time, corrected accordingly in this present work.