Extraction, Partial Purification and Characterization of 5’-Phosphodiesterase from Germinated Phaseolus mungo (Mung Bean)

5’-Phosphodiesterase (5’-PDE) is an enzyme that hydrolyses RNA to a mixture of ribonucleotide, from which 5’-guanosine monophosphate (5’-GMP) and 5’-Inosine monophosphate (5’-IMP) can be isolated. In the present work 5’PDE was extracted and partially purified from germinated mung bean. 5’-PDE activity was monitored using bis-(p-nitro phenyl phosphate) disodium salt as the substrate. The enzyme acts on substrate and releases the p-nitrophenol, which is measured at 420 nm. Purification was carried out by centrifugation, Ammonium sulphate precipitation followed by membrane filtration and heat shock treatment which gave 6.41-fold concentration. The enzyme had a pH optimum of 6.0 and showed good stability over pH range from 4 to 7.The optimum temperature for enzyme activity was found to be 600C and was also found stable at 40C.5’-PDE activity was enhanced up to 147% in the presence of Mg++. MichelisMenten equation with km 0.48 and Vmax 19230 was determined from Lineweaver Burke plot. This partially purified enzyme could be used for hydrolysis of RNA to produce 5’-GMP and 5’-adenosine monophosphate, a precursor of 5’-IMP.