http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Identification of Halohydrin Dehalogenase Mutants that Resist COBE Inhibition
Shao-Yun Chen,Xiu-Juan He,Jian-ping Wu,Gang Xu,Li-Rong Yang 한국생물공학회 2014 Biotechnology and Bioprocess Engineering Vol.19 No.1
The biocatalytic cascade conversion of ethyl4-chloroacetoacetate (COBE) to ethyl (R)-4-cyano-3-hydroxybutyrate ((R)-HN) for the preparation of atorvastatinrepresents significant economic and environmental benefits,and is catalyzed by alcohol dehydrogenase and halohydrindehalogenase (HHDH). However, as the activity of HHDHis inhibited by COBE, the cascade reaction is an inefficientone-pot reaction. In this study, substrate inhibition kineticsanalysis was performed and the inhibition by COBE wasfound to be competitive reversible inhibition. Molecularsimulation analysis was used to determine the inhibitionmechanism by COBE. The results showed that COBEbound to the active center of HHDH via the formation ofhydrogen bonds with the OH groups of S132 and Y145. Site saturation mutagenesis of residues around the activesite and at the entrance of the access tunnel was performed,and two target mutant residues were identified, F136 andW249. Small focused mutagenesis on these two residueswas performed and the F136V/W249F mutant wassuccessfully found to relieve the activity inhibition ofHHDH by COBE. The half inhibiting concentration ofmutant F136V/W249F was found to be 20-fold higher thanwild-type HHDH. The efficiency of the multi-enzymaticone-pot system for the synthesis of (R)-HN from COBEusing mutant F136V/W249F was improved significantly.
Ya-Nan Zhang,Peng He,Jian-Ping Xue,Qing Guo,Xiu-Yun Zhu,Li-Ping Fang,Jin-Bu Li 한국응용곤충학회 2017 Journal of Asia-Pacific Entomology Vol.20 No.2
The beet armyworm, Spodoptera exigua Hübner (Lepidoptera: Noctuidae), is a key pest of various agricultural crops in many countries throughout the world. The pest requires extensive use of pesticides and field-evolved resistances to conventional insecticides in China and other countries. Pinellia ternata Breit is native to the eastern part of Asia and foundmainly in China,which has been used in traditional Chinese medicines for N1000 years, but few studies have focused on the insecticidal activity of the P. ternate. In order to find natural products that could be used to control the pest in an safe, efficient and ecofriendlymanner,we first time analyzed the components of the anhydrous ethanolic extracts fromthe tubers of Pinellia ternate by using GC–MS method, and then investigated the insecticidal activities and biochemical mechanisms of the extracts against S. exigua. The result of GC–MS showed that 2-Methoxy-4-vinylphenolmay be an insecticidal active component, and we also found the extracts had notable insecticidal activity and disturbed the regular metabolismof S. exiguamainly through altering the activities of detoxification enzymes, digestive enzymes and protective enzymes. These properties suggest that the anhydrous ethanolic extracts from P. ternate can serve as a potential, efficient and ecofriendly S. exigua-control biopesticide.
Ya-Nan Zhang,Zhao-Qun Li,Xiu-Yun Zhu,Jia-Li Qian,Zhi-Ping Dong,Lu Xue,Peng He 한국응용곤충학회 2017 Journal of Asia-Pacific Entomology Vol.20 No.4
Some of the metabolic enzyme carboxylesterases (CXEs) belong to the odorant-degrading enzymes (ODEs) family in insect species, and these play a key role in the degradation of acetate sex pheromones and host plant volatiles. Athetis lepigone is one of the most important agricultural insect pests in the world, can damage> 30 species of host plants, and has caused serious declines in the yield of summer corn in North China since 2011. According to our previous studies, the sex pheromone component of the pest is a binary blend of Z7–12:OAc and Z9–14:OAc at a ratio of 3:7. However, there are no reports regarding the degradation mechanism for these two sex pheromones. Herein, we firstly identified 20 candidate CXE genes in A. lepigone using our previous adult antennal RNA-seq data. Then, we constructed a phylogenetic tree and further conducted tissue distribution analyses to determine the possible functions of these genes. Our results showed that some AlepCXEs displayed adult antennae- predominant, male antennae-biased, or leg/wing-biased expression, indicating these AlepCXEs may have distinct physiological functions and play distinct roles in the degradation of sex pheromones, host plant volatiles, and/or other xenobiotics. These findings will help us to elucidate the exact functions of these genes in the future, and also provide possible target genes for the prevention and control of A. lepigone.
Ya Nan Zhang,Jin-Bu Li,Peng He,Liang Sun,Zhao-Qun Li,Li-Ping Fang,Zhan-Feng Ye,Dao-Gui Deng,Xiu-Yun Zhu 한국응용곤충학회 2016 Journal of Asia-Pacific Entomology Vol.19 No.4
Carboxylesterases (CXEs) belong to a family of metabolic enzymes that are widely distributed in insects and other organisms and can rapidly degrade the components of sex pheromones and plant volatiles with an acetate functional group. The common cutworm, Spodoptera litura, is an important agricultural pest around the world, causing vast economic losses every year. The female sex pheromones of S. litura comprise four acetates, Z9, E11-14:OAc; Z9, E12-14:OAc; Z9-14:OAc; and E11-14:OAc, but the degradation mechanisms of these components are not well understood. By analysing previously obtained transcriptomic data of the sex pheromone glands,we identified a total of 24 putative CXE genes in S. litura. Gene expression patterns and phylogenetic analysis revealed 5 genes with antennae-specific or biased expression, and clusteredwith genes showed involvement in the degradation of sex pheromones or other detoxification in other insects. SlitCXE10was expressed specifically in the antennae of both sexes, and SlitCXE14, 17, 19, and 21 had high antenna biased expression. Interestingly, RT-PCR and qPCR tests indicated that SlitCXE24 had significantly higher expression in PG than in other tissue, and that it could be a potential candidate gene for sex pheromone degradation in PG. This study is the first to provide solid background information for the further elucidation of sex pheromone degradation, and ultimately provides potential targets for the disruption of sexual communication in S. litura for new pest management.
( Jin Jing Wang ),( Zhao Yue Wang ),( Ping He Xiu ),( Bo Run Zhang ) 한국미생물 · 생명공학회 2010 Journal of microbiology and biotechnology Vol.20 No.11
In beer, glutathione works as the main antioxidant compound, which also correlates with the stability of the beer flavor. In addition, high residual sugars in beer contribute to major nonvolatile components, which are reflected in a high caloric content. Therefore, in this study, the Saccharomyces cerevisiae GSH1 gene encoding glutamylcysteine synthetase and the Saccharomycopsis fibuligera ALP1 gene encoding α-amylase were coexpressed in industrial brewing yeast strain Y31 targeting the α- acetolactate synthase (AHAS) gene (ILV2) and alcohol dehydrogenase gene (ADH2), resulting in the new recombinant strain TY3. The glutathione content in the fermentation broth of TY3 increased to 43.83 mg/l as compared with 33.34 mg/l in the fermentation broth of Y31. The recombinant strain showed a high α-amylase activity and utilized more than 46% of the starch as the sole carbon source after 5 days. European Brewery Convention tube fermentation tests comparing the fermentation broths of TY3 and Y31 showed that the flavor stability index for TY3 was 1.3-fold higher, whereas its residual sugar concentration was 76.8% lower. Owing to the interruption of the ILV2 gene and ADH2 gene, the contents of diacetyl and acetaldehyde as off-flavor compounds were reduced by 56.93% and 31.25%, respectively, when compared with the contents in the Y31 fermentation broth. In addition, since no drug-resistant genes were introduced to the new recombinant strain, it should be more suitable for use in the beer industry, owing to its better flavor stability and other beneficial characteristics.
Wang, Jing-Jing,Wu, Hai-Feng,Sun, Tao,Li, Xia,Wang, Wei,Tao, Li-Xin,Huo, Da,Lv, Ping-Xin,He, Wen,Guo, Xiu-Hua Asian Pacific Journal of Cancer Prevention 2013 Asian Pacific journal of cancer prevention Vol.14 No.10
Lung cancer, one of the leading causes of cancer-related deaths, usually appears as solitary pulmonary nodules (SPNs) which are hard to diagnose using the naked eye. In this paper, curvelet-based textural features and clinical parameters are used with three prediction models [a multilevel model, a least absolute shrinkage and selection operator (LASSO) regression method, and a support vector machine (SVM)] to improve the diagnosis of benign and malignant SPNs. Dimensionality reduction of the original curvelet-based textural features was achieved using principal component analysis. In addition, non-conditional logistical regression was used to find clinical predictors among demographic parameters and morphological features. The results showed that, combined with 11 clinical predictors, the accuracy rates using 12 principal components were higher than those using the original curvelet-based textural features. To evaluate the models, 10-fold cross validation and back substitution were applied. The results obtained, respectively, were 0.8549 and 0.9221 for the LASSO method, 0.9443 and 0.9831 for SVM, and 0.8722 and 0.9722 for the multilevel model. All in all, it was found that using curvelet-based textural features after dimensionality reduction and using clinical predictors, the highest accuracy rate was achieved with SVM. The method may be used as an auxiliary tool to differentiate between benign and malignant SPNs in CT images.
Jiang, Chang,Liao, Fang-Xin,Rong, Yu-Ming,Yang, Qiong,Yin, Chen-Xi,He, Wen-Zhuo,Cai, Xiu-Yu,Guo, Gui-Fang,Qiu, Hui-Juan,Chen, Xu-Xian,Zhang, Bei,Xia, Liang-Ping Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.13
Objective: To compare the efficacy of taxane-based regimens in the first line setting retrospectively in Chinese patients with recurrent and/or metastatic esophageal cancer. Methods: We analyzed 102 recurrent and/or metastatic esophageal cancer patients who received taxanes-based regimens in a first-line setting from January 2009 to December 2013. Sixteen (15.7%) patients were administered Nab-PTX based chemotherapy and 86 patients (84.3%) received paclitaxel (PTX) or docetaxel (DTX) based chemotherapy. Patients in the PTX/DTX group could be further divided into TP (71 patients) and TPF (15 patients) groups. Results: The objective response rate (ORR) of all patients was 20.6%, and the disease control rate (DCR) was 67.6%. The median overall survival (OS) was 10.5 months (95% CI 10.1-16.4) and the median progression-free survival (PFS) was 6.04 months (95% CI 5.09-7.91). The DCR was higher in the TPF group than the TP group (93.3% vs. 59.1%; p = 0.015 ). There were no significant differences in ORR, OS, and PFS among Nab-PTX, TPF and TP groups. Conclusions: The three regimens of Nab-PTX based, TP and TPF proved active in a first line setting of Chinese patients with recurrent and/or metastatic esophageal cancer, and should thus be regarded as alternative treatments.