Enzymatic Synthesis of 4-Hydroxyphenyl β-D-Oligoxylosides and Their Notable Tyrosinase Inhibitory Activity
Enzymatic Synthesis of 4-Hydroxyphenyl β-D-Oligoxylosides and Their Notable Tyrosinase Inhibitory Activity
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DOI：
10.1271/bbb.80885
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发表时间：
2009-05-01
影响因子：
1.6
通讯作者：
Ando, Akikazu
中科院分区：
文献类型：
--
作者：
Chiku, Kazuhiro;Dohi, Hirofumi;Ando, Akikazu
我们从芽孢杆菌中分离纯化并鉴定了一种寡羟甲基转移酶(OxtA)。菌株KT12。在本研究中，该酶的N-末端组氨酸标记的重组形式OxtA(H)(E)在大肠杆菌中过量表达，并应用于与木聚糖和对苯二酚的反应，一步反应生成4-羟基苯基-β-D-寡糖苷，β-(Xyl)(N)-HQ(n=1-4)。得到的β-(Xyl)(N)-HQ对催化L-多巴氧化成L-多巴奎宁的蘑菇酪氨酸酶有抑制作用，其IC50值分别为3.0、0.74、0.48和0.18 mM。β-(Xyl)(4)-HQ的抑制活性是P-熊果苷(4-羟基苯基-β-D-葡萄糖苷)的35倍，其IC50值为6.3 mM。动力学分析表明，β-(Xyl)(2)-HQ、β-(Xyl)(3)-HQ和β-(Xyl)(4)-HQ对酶有竞争性抑制作用，相应的K-I值分别为0.2、0.29和0.057 mM。
We have purified and characterized an oligoxylosyl transfer enzyme (OxtA) from Bacillus sp. strain KT12. In the present study, a N-terminally His-tagged recombinant form of the enzyme, OxtA(H)(E), was overproduced in Escherichia coli and applied to the reaction with xylan and hydroquinone to produce 4-hydroxyphenyl beta-D-oligoxylosides, beta-(Xyl)(n)-HQ (n = 1-4), by one step reaction. The obtained beta-(Xyl)(n)-HQ inhibited mushroom tyrosinase, which catalyzes the oxidation of L-DOPA to L-DOPA quinine, and the IC50 values of beta-Xyl-HQ, beta-(Xyl)(2)-HQ, beta-(Xyl)(3)-HQ, and beta-(Xyl)(4)-HQ were 3.0, 0.74, 0.48, and 0.18 mM respectively. beta-(Xyl)(4)-HQ showed 35-fold more potent inhibitory activity than P-arbutin (4-hydroxyphenyl beta-D-glucopyranoside), of which the IC50 value was measured to be 6.3 mM. Kinetic analysis revealed that beta-(Xyl)(2)-HQ, beta-(Xyl)(3)-HQ, and beta-(Xyl)(4)-HQ competitively inhibited the enzyme, and the corresponding K-i values were calculated to be 0.20, 0.29, and 0.057 mM respectively.