Natural product juglone targets three key enzymes from Helicobacter pylori： inhibition assay with crystal structure characterization  

作　　者：Yun-hua KONG Liang ZHANG Zheng-yi YANG Cong HAN Li-hong HU Hua-liang JIANG Xu SHEN 

机构地区：[1]Drug Discovery and Design Center, State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 201203, China

出　　处：《Acta Pharmacologica Sinica》2008年第7期870-876,共7页中国药理学报（英文版）

基　　金：This work was supported by the National Natural Science Foundation of China （No 30525024, 20721003, and 90713046）.

摘　　要：Aim： To investigate the inhibition features of the natural product juglone （5- hydroxy-1,4-naphthoquinone） against the three key enzymes from Helicobacter pylori （cystathionine γ-synthase [HpCGS], malonyl-CoA：acyl carrier protein transacylase [HpFabD], and β-hydroxyacyl-ACP dehydratase [HpFabZ]）. Methods： An enzyme inhibition assay against HpCGS was carried out by using a continuous coupled spectrophotometric assay approach. The inhibition assay of HpFabD was performed based on the α-ketoglutarate dehydrogenase-coupled system, while the inhibition assay for HpFabZ was monitored by detecting the decrease in absorbance at 260 nm with crotonoyl-CoA conversion to β-hydroxybutyryl-CoA. The juglone/FabZ complex crystal was obtained by soaking juglone into the HpFabZ crystal, and the X-ray crystal structure of the complex was analyzed by molecular replacement approach. Results： Juglone was shown to potently inhibit HpCGS, HpFabD, and HpFabZ with the half maximal inhibitory concentration IC50 values of 7.0±0.7, 20±1, and 30±4 μmol/L, respectively. An inhibition-type study indicated that juglone was a non-competitive inhibitor of HpCGS against O-succi- nyl-L-homoserine （Ki=αKi=24 gmol/L）, an uncompetitive inhibitor of HpFabD against malonyl-CoA （αKi=7.4 μmol/L）, and a competitive inhibitor of HpFabZ against crotonoyl-CoA （Ki=6.8 μmol/L）. Moreover, the crystal structure of the HpFabZ/juglone complex further revealed the essential binding pattern ofjuglone against HpFabZ at the atomic level. Conclusion： HpCGS, HpFabD, and HpFabZ are potential targets ofjuglone.Aim： To investigate the inhibition features of the natural product juglone （5- hydroxy-1,4-naphthoquinone） against the three key enzymes from Helicobacter pylori （cystathionine γ-synthase [HpCGS], malonyl-CoA：acyl carrier protein transacylase [HpFabD], and β-hydroxyacyl-ACP dehydratase [HpFabZ]）. Methods： An enzyme inhibition assay against HpCGS was carried out by using a continuous coupled spectrophotometric assay approach. The inhibition assay of HpFabD was performed based on the α-ketoglutarate dehydrogenase-coupled system, while the inhibition assay for HpFabZ was monitored by detecting the decrease in absorbance at 260 nm with crotonoyl-CoA conversion to β-hydroxybutyryl-CoA. The juglone/FabZ complex crystal was obtained by soaking juglone into the HpFabZ crystal, and the X-ray crystal structure of the complex was analyzed by molecular replacement approach. Results： Juglone was shown to potently inhibit HpCGS, HpFabD, and HpFabZ with the half maximal inhibitory concentration IC50 values of 7.0±0.7, 20±1, and 30±4 μmol/L, respectively. An inhibition-type study indicated that juglone was a non-competitive inhibitor of HpCGS against O-succi- nyl-L-homoserine （Ki=αKi=24 gmol/L）, an uncompetitive inhibitor of HpFabD against malonyl-CoA （αKi=7.4 μmol/L）, and a competitive inhibitor of HpFabZ against crotonoyl-CoA （Ki=6.8 μmol/L）. Moreover, the crystal structure of the HpFabZ/juglone complex further revealed the essential binding pattern ofjuglone against HpFabZ at the atomic level. Conclusion： HpCGS, HpFabD, and HpFabZ are potential targets ofjuglone.

关 键 词：cystathionine γ-synthase malonyl-CoA：acyl carrier protein transacylase β-hydroxyacyl-ACP dehydratase inhibitor type complex structure 

分 类 号：R362[医药卫生—病理学]