Structural-based Screening of L-phenylglycine Aminotransferase using L-phenylalanine as the Optimal Amino Donor: Recycling of L-phenylalanine to Produce L-phenylglycine

Shuang Ping Liu,Rui Xia Liu,Jian Mao,Liang Zhang,Zhongyang Ding,Zhenghua Gu,Gui-Yang Shi 한국생물공학회 2016 Biotechnology and Bioprocess Engineering Vol.21 No.1

The aproteinogenic amino acid, L-phenylglycine, is an important side chain building block for some drugs. It would be of great commercial and environmental value to biocatalyse L-phenylalanine to L-phenylglycine, and thus replace the organic synthesis method. To produce Lphenylglycine from L-phenylalanine, an L-phenylglycine aminotransferase was screened and characterized. HpgTAO showed high homology to α-aminoadipate aminotransferase. The L-phenylalanine binding site was near the residues S26, R401, N201, and G46 in HpgTAO, and L-phenylalanine formed a hydrogen bond with Asn20, which was similar to the substrate binding mechanism of α-aminoadipate aminotransferase. HpgTAO showed increased activity in alkalescent environment below 40°C. The kinetic analysis showed that L-phenylalanine had the highest affinity to HpgTAO, which ensured the recycle biosynthesis of Lphenylglycine from L-phenylalanine. To date, it was the only aminotransferase using L-phenylalanine as an optimal amino donor. The L-phenylglycine biocatalysis operon was also constructed by co-expressing the hmaS, hmo and hpgT by a single plasmid. The first in vitro conversion of Lphenylalanine to L-phenylglycine was achieved by directly using the L-phenylalanine fermentation broth as the raw material.

Tea seed saponin(TSS) improve lipid metabolism and oxidative stress in high fat diet(HFD)-induced obese mice

Shuang Liu,Huishan Qin,Yanmin Su,Jiali Li,Wenjing Cao,Wen He,Zhen Zeng,Qi Qi Pang,Jia-Le Song 한국식품영양과학회 2021 한국식품영양과학회 학술대회발표집 Vol.2021 No.10

To investigate the effect of TSS on lipid metabolism and oxidative stress in HFD mice. The body weight and food intake were observed. The serum SOD, MDA, GSH, TC, TG, HDL-C, LDL-C were determined by kits. Western Blotting was used to detect the levels of PPAR-γ, AMPK, SIRT1 and PGC-1α. TSS treatment reduced the body weight, Lee"s index and fat organ indices of mice in the HFD group. Compared with the control(CON) group, the serum TC, TG and LDL-C in the HFD group were increased, Administrated with TSS can improve abnormal blood lipid levels. Compared with the CON group, the serum SOD level in HFD group was significantly reduced(P<0.05), and MDA level was increased; while the levels of serum MDA in the TSS group decreased and SOD level increased. The pathological sections showed that TSS could improve the degree of hepatic steatosis. TSS also increased the levels of PPAR-γ, AMPK, SIRT1 and PGC-1α, and the effect of the high-dose group was the most significant. TSS can reduce body weight and fat accumulation, improve lipid metabolism disorder and oxidative stress caused by HFD.

MnO2/graphene supported on Ni foam: an advanced electrode for electrochemical detection of Pb(II)

Liu Rui,Zhang Chao-Jun,Han Xue,Wu Tian-Heng,Liu Ri-Jia,Sun Yuan,Jin Shuang 한국탄소학회 2023 Carbon Letters Vol.33 No.3

Graphene-derived materials are an excellent electrode for electrochemical detection of heavy metals. In this study, a MnO2/graphene supported on Ni foam electrode was prepared via ultrasonic impregnation and electrochemical deposition. The resulting electrode was used to detect Pb(II) in the aquatic environment. The graphene and MnO2 deposited on the Ni foam not only improved active surface area, but also promoted the electron transfer. The electrochemical performance towards Pb(II) was evaluated by cyclic voltammetry (CV) and square wave anodic stripping voltammetry (SWASV). The prepared electrode exhibited lower limit of detection (LOD, 0.2 μM (S/N = 3)) and good sensitivity (59.9 μAμM−1) for Pb(II) detection. Moreover, the prepared electrodes showed good stability and reproducibility. This excellent performance can be attributed to the strong adhesion force between graphene and MnO2, which provides compact structures for the enhancement of the mechanical stability. Thus, these combined results provide some technical considerations and scientific insights for the detection of heavy metal ions using composite electrodes.

Photocatalytic degradation of tetracycline with Fe3O4/g-C3N4/TiO2 catalyst under visible light

Liu Rui,Zhang Xin,Han Xue,Sun Yuan,Jin Shuang,Liu Ri-jia 한국탄소학회 2024 Carbon Letters Vol.34 No.1

Fe3O4/g-C3N4/TiO2 catalyst has been fabricated using a simple ultrasonic method with high photocatalytic activity. The morphology, structure and optical properties of Fe3O4/g-C3N4/TiO2 were systematically investigated by a variety of characterization techniques. The optimum degradation conditions were investigated by degrading tetracycline (TC) under visible light irradiation. The results showed that the degradation efficiency was the highest when the initial TC concentration was 5.0 mg/L, the pH value was 11 and the catalyst dosage was 1.0 g/L. After 100 min of visible light irradiation, the degradation efficiency of TC achieved at 73.61%, which was 1.64 and 1.19 times that of g-C3N4 and Fe3O4/g-C3N4, respectively. Moreover, Fe3O4/g-C3N4/TiO2 had good stability and recyclability. The results of capture experiments showed that ‧O2− and ‧OH were the main active species during the photocatalytic process, and a possible photocatalytic reaction mechanism of Fe3O4/g-C3N4/TiO2 catalyst was proposed. This study provides a new way to improve the photocatalytic performance of g-C3N4, which has great potential in degrading pollutants such as antibiotics in wastewater.

Panaxadiol saponins treatment caused the subtle variations in the global transcriptional state of Asiatic corn borer, Ostrinia furnacalis

Liu, Shuangli,Xu, Yonghua,Gao, Yugang,Zhao, Yan,Zhang, Aihua,Zang, Liansheng,Wu, Chunsheng,Zhang, Lianxue The Korean Society of Ginseng 2020 Journal of Ginseng Research Vol.44 No.1

Background: The lepidopteran Asiatic corn borer (ACB), Ostrinia furnacalis (Guenee), has caused huge economic losses throughout the Asian-Western Pacific region. Usually, chemical pesticides are used for the control, but excessive use of pesticides has caused great harm. Therefore, the inartificial ecotypic pesticides to ACB are extremely essential. In our previous study, we found that panaxadiol saponins (PDS) can effectively reduce the harm of ACB by causing antifeedant activity. Therefore, it is necessary to reveal the biological molecular changes in ACB and the functionary mechanism of PDS. Methods: We analyzed the global transcription of ACB with different PDS concentration treatment (5 mg/mL, 10 mg/mL, and 25 mg/mL) by high-throughput sequencing and de novo transcriptome assembly method. Results: PDS treatment could cause the changes of many gene expressions which regulate its signal pathways. The genes in peroxisome proliferator-activated receptor (PPAR) signaling pathway were significantly downregulated, and then, the downstream fatty acid degradation pathway had also been greatly affected. Conclusion: Through this experiment, we hypothesized that the occurrence of antifeedant action of ACB is because the PDS brought about the downregulation of FATP and FABP, the key regulators in the PPAR, and the downregulation of FATP and FABP exerts further effects on the expression of SCD-1, ACBP, LPL, SCP-X, and ACO, which leads to the disorder of PPAR signaling pathway and the fatty acid degradation pathway. Not only that, PDS treatment leads to enzyme activity decrease by inhibiting the expression of genes associated with catalytic activity, such as cytochrome P450 and other similar genes.

Panaxadiol saponins treatment caused the subtle variations in the global transcriptional state of Asiatic corn borer, Ostrinia furnacalis

Shuangli Liu,Yonghua Xu,Yugang Gao,Yan Zhao,Aihua Zhang,Liansheng Zang,Chunsheng Wu,Lianxue Zhang 고려인삼학회 2020 Journal of Ginseng Research Vol.44 No.1

Background: The lepidopteran Asiatic corn borer (ACB), Ostrinia furnacalis (Guenee), has caused hugeeconomic losses throughout the Asian-Western Pacific region. Usually, chemical pesticides are used forthe control, but excessive use of pesticides has caused great harm. Therefore, the inartificial ecotypicpesticides to ACB are extremely essential. In our previous study, we found that panaxadiol saponins(PDS) can effectively reduce the harm of ACB by causing antifeedant activity. Therefore, it is necessary toreveal the biological molecular changes in ACB and the functionary mechanism of PDS. Methods: We analyzed the global transcription of ACB with different PDS concentration treatment (5 mg/mL, 10 mg/mL, and 25 mg/mL) by high-throughput sequencing and de novo transcriptome assemblymethod. Results: PDS treatment could cause the changes of many gene expressions which regulate its signalpathways. The genes in peroxisome proliferatoreactivated receptor (PPAR) signaling pathway weresignificantly downregulated, and then, the downstream fatty acid degradation pathway had also beengreatly affected. Conclusion: Through this experiment, we hypothesized that the occurrence of antifeedant action of ACBis because the PDS brought about the downregulation of FATP and FABP, the key regulators in the PPAR,and the downregulation of FATP and FABP exerts further effects on the expression of SCD-1, ACBP, LPL,SCP-X, and ACO, which leads to the disorder of PPAR signaling pathway and the fatty acid degradationpathway. Not only that, PDS treatment leads to enzyme activity decrease by inhibiting the expression ofgenes associated with catalytic activity, such as cytochrome P450 and other similar genes.

Hydrogen sulfide protects from acute kidney injury via attenuating inflammation activated by necroptosis in dogs

Shuang Wang,XingYao Liu,Yun Liu 대한수의학회 2022 Journal of Veterinary Science Vol.23 No.5

Background: The treatment of acute kidney injury (AKI), a common disease in dogs, is limited. Therefore, an effective method to prevent AKI in veterinary clinics is particularly crucial. Objectives: Hydrogen sulfide (H2S) is the third gaseous signal molecule involved in various physiological functions of the body. The present study investigated the effect of H2S on cisplatin-induced AKI and the involved mechanisms in dogs. Methods: Cisplatin-injected dogs developed AKI symptoms as indicated by renal dysfunction and pathological changes. In the H2S-treated group, 50 mM sodium hydrosulfide (NaHS) solution was injected at 1 mg/kg/h for 30 min before cisplatin injection. After 72 h, tissue and blood samples were collected immediately. We performed biochemical tests, optical microscopy studies, analysis with test kits, quantitative reverse-transcription polymerase chain reaction, and western blot analysis. Results: The study results demonstrated that cisplatin injection increased necroptosis and regulated the corresponding protein expression of receptor interacting protein kinase (RIPK) 1, RIPK3, and poly ADP-ribose polymerase 1; furthermore, it activated the expressions of inflammatory factors, including tumor necrosis factor-alpha, nuclear factor kappa B, and interleukin-1β, in canine kidney tissues. Moreover, cisplatin triggered oxidative stress and affected energy metabolism. Conversely, an injection of NaHS solution considerably reduced the aforementioned changes. Conclusions: In conclusion, H2S protects the kidney from cisplatin-induced AKI through the mitigation of necroptosis and inflammation. These findings provide new and valuable clues for the treatment of canine AKI and are of great significance for AKI prevention in veterinary clinics.

Amino acid, fatty acid, and carbohydrate metabolomic profi les with ginsenoside-induced insecticidal effi cacy against Ostrinia furnacalis (Guenee)

Shuangli Liu,Xiaohui Wang,Rui Zhang,Mingjie Song,Nanqi Zhang,Wanying Li,Yingping Wang,Yonghua Xu,Lianxue Zhang 고려인삼학회 2020 Journal of Ginseng Research Vol.44 No.4

Background: Previous studies have shown the insecticidal efficacy of ginsenosides. In the present study,we aimed to investigate the metabolic mechanism related to the inhibitory effect of panaxadiol saponins(PDSs) against the Asian corn borer Ostrinia furnacalis (Guenee). Methods: Third instar larvae of O. furnacalis were fed normal diets with different concentrations of PDSsfor 4 days. The consumption index, relative growth rate, approximate digestibility, and conversion ofingested and digested food were recorded. A targeted gas chromatographyemass spectrometry assaywas performed to detect the profiles of amino acids, fatty acids, and carbohydrates in larvae ofO. furnacalis. In addition, the activity of detoxification-related enzymes was determined. Results and Conclusions: PDSs decreased the consumption index, relative growth rate, approximate digestibility,and conversion of ingested and digested food in the 3rd instar larvae of O. furnacalis in a dosedependentmanner. PDSs decreased 15 free amino acids, 16 free fatty acids, and 5 carbohydrates andincreased the levels of palmitoleic acid, palmitic acid, and 9-octadecenoic acid in the 3rd instar larvae. The activity of detoxification-related enzymes, such as acetylcholinesterase, glutathione S-transferase,cytochrome P450, carboxylesterase, trehalase, acid phosphatase, and alkaline phosphatase, was reducedin a dose-dependent manner in the 3rd instar larvae exposed to PDSs. These data confirmed theinhibitory effect of PDSs against growth, food utilization, and detoxification in the 3rd instar larvae ofO. furnacalis and the potential for using PDSs as an efficient tool for insect pest management forO. furnacalis larvae.

A striking flail chest: a rare manifestation in Cronkhite-Canada syndrome

Shuang Liu,Ge Chong Ruan,Yan You,Jia Ming Qian,Ji Li 대한장연구학회 2019 Intestinal Research Vol.17 No.1

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Event-triggering Control of Networked Control Systems Under Random Deception Attacks: An Adaptive Triggering Strategy With Saturation Constraint

Shuang Liu,Chunmei Duan,Wuneng Zhou 제어·로봇·시스템학회 2023 International Journal of Control, Automation, and Vol.21 No.9

This paper deals with the stochastic stability problem of the closed-loop system under deception attacks based on an adaptive event-triggering scheme (AETS) with saturation constraint. Some novel stability criteria related to networked control systems under deception attacks are devised by taking the fixed threshold which is difficult to adapt to changeable systems into account. An adaptive event-triggering scheme with saturation constraint involving a threshold variable with system states is proposed to reduce network load, and the desired controller gain matrix is obtained by employing the linear matrix inequalities (LMIs) technique. Moreover, the LyapunovKrasovskii method is used to obtain sufficient conditions for ensuring the stability of the system. In the end, the simulation results are shown to indicate the validity of the proposed method.