Abstract

Due to its various biological activities, the roots of Brassica rapa (turnip), has been applied as a therapeutic agent in traditional medicine. The current study aimed to purify a plant peroxidase (POD; designated as TRP) from Algerian white turnip (B. rapa, variety rapa) roots, to homogeneity and to characterise it biochemically. The molecular weight of the purified TRP was determined to be ∼58 kDa as estimated by sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE) and high-performance liquid chromatography (HPLC). The TRP Reinheitzahl values (RZ) and specific activity were 2.9 and 14,500 U/mg, respectively. Its N-terminal sequence exhibited high identity with those of class III-PODs. TRP showed optimal activity at 55 °C and pH 6 (guaiacol), was completely inhibited by sodium azide (NaN₃) and potassium cyanide (KCN) and exhibited greater catalytic efficiency than that of the well-known horseradish peroxidase (HRP) from Armoracia rusticana. TRP demonstrated antioxidant activities with 45% and 61.49% of 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS^•) and hydroxyl (^•OH) radical scavenging, respectively, as well as ferrous ion chelating (52.96%) and reducing (48.32%) powers. This study provides information regarding the potential role of TRP in enzyme therapy (as applied in the pharmaceutical and medicinal industries), with biological eradication of free radicals.

摘要

由于其多种生物活性，芸苔（芜菁）的根已被用作传统医学中的治疗剂。目前的研究旨在从阿尔及利亚白萝卜（B. rapa，品种rapa) 根、同质性和生化特征。经十二烷基硫酸钠聚丙烯酰胺凝胶电泳 (SDS-PAGE) 和高效液相色谱 (HPLC) 估计，纯化的 TRP 的分子量约为 58 kDa。TRP Reinheitzahl 值 (RZ) 和比活性分别为 2.9 和 14,500 U/mg。其 N 端序列与 III 类 POD 的序列具有高度一致性。_{TRP 在 55 °C 和 pH 6（愈创木酚）下表现出最佳活性，被叠氮化钠 (NaN 3} ) 和氰化钾 (KCN)完全抑制，并且表现出比Armoracia著名的辣根过氧化物酶 (HRP) 更高的催化效率乡村. TRP 表现出抗氧化活性，分别具有 45% 和 61.49% 的 2,2'-azino-bis(3-ethylbenzothiazline-6-sulfonic acid) (ABTS ^• ) 和羟基 ( ^• OH) 自由基清除剂以及亚铁离子螯合（52.96%）和减少（48.32%）的权力。这项研究提供了有关 TRP 在酶疗法（如应用于制药和医药行业）中的潜在作用的信息，以及生物根除自由基。