STUDY OF NUCLEOSIDE DEGRADING ENZYME ACTIVITIES IN BEAN, ORGANIC BEAN, OKRA, ORGANIC OKRA, SQUASH AND ORGANIC SQUASH

Abstract

Pyrimidine and purine nucleotide metabolism are essential for development and growth of all organisms. Nucleoside degradation reactions have been found in virtually all organisms. Many enzymes are involved in the degradation and salvage of nucleotides, nucleobases and nucleosides. Deaminases contribute in interconversion of one nucleoside into another by removing amino groups from the base. Nucleoside hydrolase is a glycosidase that catalyzes the cleavage of the N-glycosidic bond in nucleosides to facilitate recycling of nucleobases.

The nucleoside degrading enzyme activity was tested by adding a crude protein extract from 5-9 day old bean, organic bean, okra, organic okra, squash and organic squash seedlings to reaction mixtures containing either inosine, uridine, cytidine, adenosine, or 2'-deoxyadenosine. The activities of the enzyme were determined on a Dionex Ultimate 3000 High Performance Liquid chromatography system (HPLC). Nucleosidases were found to be active in all six plants and specific activities are reported.

There are variations in the level of activities observed between bean, organic bean, okra, organic okra, squash and organic squash. Based on the specific activities the highest activity was recorded for uridine, cytidine and adenosine in different types of seeds while inosine and 2'deoxyadenosine had the lowest activity. Bean was the lowest in activity with all five nucleosidases compared to nucleosidase metabolizing activities in organic bean, okra, organic okra, squash and organic squash.