Differential in vitro inhibition of polyphenoloxidase from a wild edible mushroom Lactarius salmonicolor |
| |
Authors: | Nurcan Dedeoglu Ozen Ozensoy Guler |
| |
Institution: | 1. Department of Chemistry, Balikesir University Science &2. Art Faculty, Cag?s-Kampus10100, Balikesir, Turkey |
| |
Abstract: | The polyphenol oxidase (LsPPO) from a wild edible mushroom Lactarius salmonicolor was purified using a Sepharose 4B-L-tyrosine-p-amino benzoic acid affinity column. At the optimum pH and temperature, the KM and VMax values of LsPPO towards catechol, 4-methylcatechol and pyrogallol were determined as 0.025 M & 0.748 EU/mL, 1.809 × 10? 3 M & 0.723 EU/mL and 9.465 × 10? 3 M & 0.722 EU/mL, respectively.Optimum pH and temperature values of LsPPO for the three substrates above ranged between the pH 4.5–11.0 and 5–50°C. Enzyme activity decreased due to heat denaturation with increasing temperature. Effects of a variety of classical PPO inhibitors were investigated opon the activity of LsPPO using catechol as the substrate. IC50 values for glutathione, p-aminobenzenesulfonamide, L-cysteine, L-tyrosine, oxalic acid, β-mercaptoethanol and syringic acid were determined as 9.1 × 10? 4, 2.3 × 10? 4 M, 1.5 × 10? 4 M, 3.8 × 10? 7 M, 1.2 × 10? 4 M, 4.9 × 10? 4 M, and 4 × 10? 4 M respectively. Thus L-tyrosine was by far the most effective inhibitor. Interestingly, sulfosalicylic acid behaved as an activator of LsPPO in this study. |
| |
Keywords: | Lactarius salmonicolor affinity chromatography inhibition enzymatic browning polyphenoloxidase |
|
|