Inhibitory effect of black cumin (Nigella sativa) seed essential oil on Fusobacterium nucleatum L-methionine-γ-lyase (L-methioninase) activity
Inhibitory effect of black cumin (Nigella sativa) seed essential oil on Fusobacterium nucleatum L-methionine-γ-lyase (L-methioninase) activity
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黑孜然 (Nigella sativa) 种子精油对具核梭杆菌 L-蛋氨酸-γ-裂解酶 (L-蛋氨酸酶) 活性的抑制作用
DOI：
10.1093/femsle/fnab041
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发表时间：
2021
影响因子：
2.1
通讯作者：
Shibuya Koji
中科院分区：
文献类型：
--
作者：
Ishikawa Masao;Murata Takatoshi;Okamoto Masaaki;Miyanohara Mayu;Yamashita Mamiko;Hanada Nobuhiro;Senpuku Hidenobu;Shibuya Koji
酶L-甲硫氨酸-γ-裂解酶通常存在于广泛的细菌中，催化L-甲硫氨酸的α-消除和γ-消除，以产生α-酮基丁酸甲酯、α-酮基丁酸酯和氨。据报道，黑孜然籽精油（BC油）对甲基异黄酮表现出抗氧化活性。因此，我们假设BC油也可以抑制甲基异麦芽糖的产生。在这项研究中，我们的目的是评估BC油的抑制作用L-蛋氨酸-γ-裂解酶活性的核梭杆菌。重组L-甲硫氨酸-γ-裂解酶在适当条件下与BC油及其组分百里醌一起孵育。为了分析L-甲硫氨酸-γ-裂解酶活性，测定α-酮丁酸和氨浓度。10 µg/mL BC油（P< 0.01）和16.4 µg/mL百里醌（P< 0.05）可显著降低α-酮丁酸和氨的浓度。酶动力学分析表明，L-蛋氨酸-γ-裂解酶与百里醌之间存在混合抑制作用。综上所述，BC油不仅对甲基蛋氨酸具有抑制作用，而且通过抑制L-蛋氨酸-γ-裂解酶的活性而抑制甲基蛋氨酸的产生。麝香草醌可能是BC油的这些作用的主要原因。因此，天然BC油的应用不仅适用于医疗用途，而且适用于生活的其他领域。
The enzyme L-methionine-γ-lyase is commonly found in a wide range of bacteria and catalyzes the α-elimination and γ-elimination of L-methionine to produce methyl mercaptan, α-ketobutyrate and ammonia. Black cumin seed essential oil (BC oil) reportedly exhibits deodorizing activity against methyl mercaptan. Therefore, we hypothesized that BC oil may also suppress methyl mercaptan production. In this study, we aimed to evaluate the inhibitory effect of BC oil on L-methionine-γ-lyase activity inFusobacterium nucleatum. Recombinant L-methionine-γ-lyase was incubated under appropriate conditions with BC oil and its constituent thymoquinone. To analyze L-methionine-γ-lyase activity, α-ketobutyric acid and ammonia concentrations were determined. The concentrations of α-ketobutyric acid and ammonia were significantly decreased by 10 µg mL−1of BC oil (P< 0.01) and 16.4 µg/mL of thymoquinone (P< 0.05). An enzyme kinetic assay showed a mixed inhibition pattern between L-methionine-γ-lyase and thymoquinone. In conclusion, BC oil not only had a deodorizing effect against methyl mercaptan but also an inhibitory effect on methyl mercaptan production through the suppression of L-methionine-γ-lyase activity. Thymoquinone may be mainly responsible for these effects of BC oil. Thus, application of natural BC oil may be adapted not only for medical use but also in other areas of life.