A comparative kinetic study on β-amylase and its antioxidant property in germinated and non germinated seeds of Glycine max. L

Abstract

Enzyme activity plays a key role in each stage of plant development starting from the initial seed germination responses. A comparative analysis of beta amylase activity was performed, isolated from germinated and non germinated Glycine max seeds, which was partially purified by dialysis. The optimum pH and temperature for germinated seeds was found to be 4.5 and 37⁰ C and that for non germinated seeds were 5.5 and 75⁰ C respectively. MnCl₂ and CoCl₂ exhibited marked activating effect on the enzyme, while HgCl₂ was a potent inhibitor for both seeds. The K_m and Vmax value for β-amylase with soluble starch as substrate was found to be 3.03mg/ml and 6.6micromol/min/ml for germinated seed and for non germinated seeds it was found to be 5mg/m and 10micromole/min/ml respectively. The molecular weight of partially purified enzyme was 57±1kDa on SDS PAGE with 1.918 fold purification and 27.98% yield for germinated seeds and for non germinated seeds the purification fold was 1.507 with 26.65% yield. The enzyme showed highest amount of total antioxidant activity of 304µg/ml in partially purified germinated seed. For ABTS free radical scavenging activity, partially purified enzyme from germinated seed showed the highest of 76.09% activity with an IC₅₀ value of 58.20µg/ml. Germinated seeds have highest enzymatic activity which can be considered for several industrial purposes.