Adenosine Deaminating/ Hydrolyzing Enzymes from Alaska pea seeds (Pisum sativum)

Abstract

Nucleoside deaminases and nucleoside hydrolases are essential within the purine salvage pathway to recycle purine bases to promote cellular functions such as DNA synthesis, cytokinin metabolism, and more. Plants such as the Alaska pea (Pisum sativum) rely heavily on these enzymes, yet the enzymatic and structural characterizations of these proteins are limited. A 67 kilodalton (kDa) protein was isolated from germinated Alaska pea seeds with a 103 fold purification and 2.8 % recovery. The analysis of the enzymatic activity of this protein revealed adenosine is metabolized to inosine, adenine, and hypoxanthine suggesting a bifunctional enzyme combining nucleosidase and deaminase activities. This dimeric protein had an inosine Michaelis constant of 268 μM 78 μM. The optimum pH for enzymatic activity was determined to be pH 6. Research involving plant based nucleoside deaminases and nucleoside hydrolases can provide an origin of reference in the development of compounds that can be used as herbicides.