Fully Deacetylated Chitooligosaccharides Act as Efficient Glycoside Hydrolase Family 18 Chitinase Inhibitors.
Fully Deacetylated Chitooligosaccharides Act as Efficient Glycoside Hydrolase Family 18 Chitinase Inhibitors.
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完全脱乙酰化的几丁寡糖可作为有效的糖苷水解酶家族 18 几丁质酶抑制剂。
DOI：
10.1074/jbc.m114.564534
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发表时间：
2014-06-20
影响因子：
4.8
通讯作者：
Yang, Qing
中科院分区：
文献类型：
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作者：
Chen, Lei;Zhou, Yong;Yang, Qing
几丁质酶小分子抑制剂作为杀虫剂、杀菌剂和平喘剂具有潜在的应用前景。在这里，我们报告了一系列完全脱乙酰化的壳寡糖（GlcN）（2-7）可以作为抑制剂对昆虫几丁质酶OfChtI，人类几丁质酶HsCht，和细菌几丁质酶SmChiA和SmChiB的IC 50值在微摩尔至毫摩尔的水平。将混合的（GlcN）（2-7）注射到昆虫Ostriniapericacalis的五龄幼虫中，导致85%的幼虫在幼虫期被捕获，并且在10天后死亡，这也表明（GlcN）（2-7）在体内可能抑制OfChtI。在2.0埃的分辨率下获得了与（GlcN）（5，6）络合的OfChtI（OfChtI-CAD）的催化结构域的晶体结构。这些结构，以及突变和热力学分析表明，抑制剂的-1 GlcN残基与酶的催化Glu（148）之间的相互作用强烈相关。基于结构的比较表明，完全脱乙酰壳寡糖模仿底物壳寡糖结合到活性裂缝。本文首次报道了完全脱乙酰壳寡糖的抑菌活性及其抑菌机理。由于完全脱乙酰化的壳寡糖可以很容易地从自然界中最丰富的物质之一甲壳素中衍生出来，因此这项工作也为开发环境友好的几丁质酶抑制剂提供了平台。
Small molecule inhibitors against chitinases have potential applications as pesticides, fungicides, and antiasthmatics. Here, we report that a series of fully deacetylated chitooligosaccharides (GlcN)(2-7) can act as inhibitors against the insect chitinase OfChtI, the human chitinase HsCht, and the bacterial chitinases SmChiA and SmChiB with IC50 values at micromolar to millimolar levels. The injection of mixed (GlcN)(2-7) into the fifth instar larvae of the insect Ostrinia furnacalis resulted in 85% of the larvae being arrested at the larval stage and death after 10 days, also suggesting that (GlcN)(2-7) might inhibit OfChtI in vivo. Crystal structures of the catalytic domain of OfChtI (OfChtI-CAD) complexed with (GlcN)(5,6) were obtained at resolutions of 2.0 angstrom. These structures, together with mutagenesis and thermodynamic analysis, suggested that the inhibition was strongly related to the interaction between the -1 GlcN residue of the inhibitor and the catalytic Glu(148) of the enzyme. Structure-based comparison showed that the fully deacetylated chitooligosaccharides mimic the substrate chitooligosaccharides by binding to the active cleft. This work first reports the inhibitory activity and proposed inhibitory mechanism of fully deacetylated chitooligosaccharides. Because the fully deacetylated chitooligosaccharides can be easily derived from chitin, one of the most abundant materials in nature, this work also provides a platform for developing eco-friendly inhibitors against chitinases.