Abstract
The developmental transition in plant leaves, for example greening and senescence, is supported by precise regulation of protein synthesis and degradation. Therefore, investigation of proteases provides important information for plastid maturation. Previously we reported three types of protease activity in barley leaves. This activity was analyzed by Suc-Leu-Leu-Val-Tyr-MCA. These enzymes required sodium dodecyl sulfate (SDS) at concentrations of 0.1%, and 0.02%, in addition to no requirement. The activity with 0.1% SDS showed a good correlation with development and senescence of plastids. In this study, the enzyme was purified by DE52 anion exchange, Q Sepharose FF anion exchange, and Superdex 200 gel-filtration chromatography. Molecular weight of the enzyme was estimated to be approximately 50 k by Superdex 200 chromatography. Additionally, this enzyme had maximum activity in neutral pH region. We are now, under way on complete purification, inhibitor study and substrate specificity to reveal enzymatic properties of this enzyme.
