Bioconversion of ginsenoside Rc into Rd by a novel α-L-arabinofuranosidase, Abf22-3 from Leuconostoc sp. 22-3: cloning, expression, and enzyme characterization.

Liu, Qing-Mei,Jung, Hae-Min,Cui, Chang-Hao,Sung, Bong-Hyun,Kim, Jin-Kwang,Kim, Song-Gun,Lee, Sung-Taik,Kim, Sun-Chang,Im, Wan-Taek N.V. Swets en Zeitlinger 2013 Antonie van Leeuwenhoek Vol.103 No.4

<P>A novel α-L-arabinofuranosidase (Abf22-3) that could biotransform ginsenoside Rc into Rd was obtained from the ginsenoside converting Leuconostoc sp. strain 22-3, isolated from the Korean fermented food kimchi. The gene, termed abf22-3, consisting of 1,527 bp and encoding a protein with a predicted molecular mass of 58,486 Da was cloned into the pMAL-c2x (TEV) vector. A BLAST search using the Abf22-3's amino acid sequence revealed significant homology to that of family 51 glycoside hydrolases. The over-expressed recombinant Abf22-3 in Escherichia coli BL21 (DE3) catalyzed the hydrolysis of the arabinofuranoside moiety attached to the C-20 position of ginsenoside Rc under optimal conditions of pH 6.0 and 30 C. This result indicated that Abf22-3 selectively converts ginsenoside Rc into Rd, but did not catalyze the hydrolysis of glucopyranosyl groups from Rc or other ginsenosides such as Rb1 and Rb2. Over-expressed recombinant enzymes were purified by two steps with amylose-affinity and DEAE-cellulose chromatography and then characterized. The kinetic parameters for α-L-arabinofuranosidase showed apparent Km and Vmax values of 0.95 0.02 μM and 1.2 0.1 μmol min(-1) mg of protein(-1) against p-nitrophenyl-α-L-arabinofuranoside, respectively. Using a purified MBP-Abf22-3 (10 μg/ml), 0.1 % of ginsenoside Rc was completely converted to ginsenoside Rd within 20 min.</P>

Electrochemical Behavior of Sm(III) on the Aluminium-Gallium Alloy Electrode in LiCl-KCl Eutectic

Ye, Chang-Mei,Jiang, Shi-Lin,Liu, Ya-Lan,Xu, Kai,Yang, Shao-Hua,Chang, Ke-Ke,Ren, Hao,Chai, Zhi-Fang,Shi, Wei-Qun Korean Radioactive Waste Society 2021 방사성폐기물학회지 Vol.19 No.2

In this study, the electrochemical behavior of Sm on the binary liquid Al-Ga cathode in the LiCl-KCl molten salt system is investigated. First, the co-reduction process of Sm(III)-Al(III), Sm(III)-Ga(III), and Sm(III)-Ga(III)-Al(III) on the W electrode (inert) were studied using cyclic voltammetry (CV), square-wave voltammetry (SWV) and open circuit potential (OCP) methods, respectively. It was identified that Sm(III) can be co-reduced with Al(III) or Ga(III) to form Al_zSm_y or Ga_xSm_y intermetallic compounds. Subsequently, the under-potential deposition of Sm(III) at the Al, Ga, and Al-Ga active cathode was performed to confirm the formation of Sm-based intermetallic compounds. The X-ray diffraction (XRD) and scanning electron microscopy-energy dispersive spectroscopy (SEM-EDS) analyses indicated that Ga₃Sm and Ga₆Sm intermetallic compounds were formed on the Mo grid electrode (inert) during the potentiostatic electrolysis in LiCl-KCl-SmCl₃-AlCl₃-GaCl₃ melt, while only Ga₆Sm intermetallic compound was generated on the Al-Ga alloy electrode during the galvanostatic electrolysis in LiCl-KCl-SmCl₃ melt. The electrolysis results revealed that the interaction between Sm and Ga was predominant in the Al-Ga alloy electrode, with Al only acting as an additive to lower the melting point.

Cervical Cancer Gene Therapy by Gene Loaded PEG-PLA Nanomedicine

Liu, Bo,Han, Shu-Mei,Tang, Xiao-Yong,Han, Li,Li, Chang-Zhong Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.12

Background and Aims: Advances in the treatment of cervical cancer over the last decade have predominantly involved the development of genes directed at molecular targets. Gene therapy is recognized to be a novel method for the treatment of cervical cancer. Genes can be administered into target cells via nanocarriers. This study aimed to develop systemically administrable nano-vectors. Floate (Fa) containing gene loaded nanoparticles (NPs) could target HeLa human cervical cancer cells through combination with receptors on the cells to increase the nuclear uptake of genetic materials. Methods: Fa was linked onto Poly (ethylene glycol)-b-poly (D, L-lactide) (PEG-PLA) to form Fa-PEG-PLA, and the resulting material was used to load plasmids of enhanced green fluorescence protein (pEGFP) to obtain gene loaded nanoparticles (Fa-NPs/DNA). Physical-chemical characteristics, in vitro release and cytotoxicity of Fa-NPs/DNA were evaluated. The in vitro transfection efficiency of Fa-NPs/DNA was evaluated in HeLa cells and human umbilical vein endothelial cells (HUVEC). PEG-PLA without Fa was used to load pEGFP from NPs/DNA as a control. Results: Fa-NPs/DNA has a particle size of 183 nm and a gene loading quantity of 92%. After 72h of transfection, Fa-NPs/DNA displayed over 20% higher transfection efficiency than NPs/DNA and 40% higher than naked DNA in HeLa cells. However, in HUVECs, no significant difference appeared between Fa-NPs/DNA and NPs/DNA. Conclusions: Fa-PEG-PLA NPs could function as excellent materials for gene loading. This nano-approach could be used as tumor cell targeted medicine for the treatment of cervical cancer.

Zostera marina Seed Burial can be Enhanced by Manila Clam Ruditapes philippinarum: A Microcosm Study

Chang-Jun Li,Wen Tao Li,Jianying Liu,Xiu-mei Zhang,Peidong Zhang 한국해양과학기술원 2017 Ocean science journal Vol.52 No.2

Seagrass seed bank plays a key role in the regeneration of new vegetation when seagrasses are removed by the natural or man-made disaster. Various factors may affect the development of sediment seed bank. We conducted a microcosm experiment to test the effects of burrowing and feeding activities of Manila clam, Ruditapes philippinarum on the burial of Zostera marina seeds in sediments. The effects of lasting time (3-hour, 1-day, 3-day, 7-day, 14-day and 28-day), clam density (0, 2, 4 and 8 clams with shell length of 3 cm in each microcosm) and clam size (shell length of 2, 3 and 4 cm at 4-clam density) on seed burial were examined in plastic microcosm cores (30 cm high × 10 in inner diameter) in a 28-day period. Results showed that the seed burial depth significantly increased with time, the density and the size of clams. No seeds were buried in the sediment in the cores without clams during the whole experiment period. For the 3-cm clams, about 91.61% of the seeds were buried in the sediment at the end of the experiment in the high-density treatment (8 clams at each core); while in the medium and low-density treatments (4 and 2 clams in each core, respectively), about 76.93% and 60.61% of the seeds were buried in the sediment, respectively. For the size treatments, large (4 cm) clams buried 89.56% of the seeds at the end of the experiment, much more than those of medium (3 cm, 76.93%) and small (2 cm, 61.50%) size clams. During the whole experiment period, nearly all of the buried seeds were at a depth of from 0 cm to 5 cm. These results suggested that Manila clam Ruditapes philippinarum may play an important positive role in seagrass seed bank dynamics in the field.

DAZL binds to the transcripts of several Tssk genes in germ cells

Mei Zeng,Wen Qian Deng,Xin Ying Wang,Wei Min Qiu,Yan Yan Liu,Hua Qin Sun,Da Chang Tao,Si Zhong Zhang,Yong Xin Ma 한국생화학분자생물학회 2008 BMB Reports Vol.41 No.4

Molecular cloning, chromosomal localization and expression profiling of porcine selenoprotein M gene

Ji-Chang Zhou,Hua Zhao,Jia-Yong Tang,Jun-Gang Li,Xiao-Li Liu,Yu-Mei Zhu 한국유전학회 2011 Genes & Genomics Vol.33 No.5

Selenoprotein M may regulate a myriad of biological processes through its redox function. In pigs, neither the nucleotide sequence nor the amino acid sequence is known. Furthermore,patterns of tissue expression and regulation by dietary selenium (Se) have not been examined. We determined the full coding sequence (CDS) and the chromosomal location of the porcine gene, SELM, and described its expression profile in vivo under different dietary Se concentrations. The cDNA sequence of porcine SELM from the start codon to the poly(A) tail was cloned by reverse transcription PCR. The CDS contained 429bases with a typical mammalian selenocysteine insertion sequence of form 2 (F2) located in the 3′-untranslated region. The gene was mapped to chromosome 14q21, where porcine SELM and its neighboring genes exhibited a similar organization to human homologues on chromosome 22q12.2. The expression pattern of SELM mRNA in muscle, thyroid, cerebral cortex, pituitary, testis, liver, and kidney was analyzed with real-time quantitative PCR in young male pigs fed a Se-deficient corn-soybean meal basal diet supplemented with 0.0, 0.3,or 3.0 mg Se/kg in the form of Se-rich yeast. Though the SELM mRNA abundance in each of the 7 tissues was not affected by the dietary Se concentrations, it was significantly higher in thyroid (P < 0.01) than in cerebral cortex, pituitary,testis, liver, and kidney at all of the 3 dietary Se concentrations.

Fixed‑time non‑singular terminal sliding mode control for PMSM drive systems

Huixiang Liu,Keqi Mei,Lu Liu,Yafei Chang,Shihong Ding,Hanzhang Zhang,Jun Wang 전력전자학회 2024 JOURNAL OF POWER ELECTRONICS Vol.24 No.2

To further improve the response speed and anti-interference capability of permanent magnet synchronous motors (PMSMs), many advanced control algorithms have been developed. Among the various advanced controls, the fixed-time terminal sliding mode control is one of the effective methods. However, there are still some problems, e.g., too many parameters imposed on the control design in the existing results. In this paper, a fixed-time non-singular terminal sliding mode control (FTNTSMC) method is proposed for the speed loop of a PMSM drive system. First, to improve the closed-loop performance of the PMSM drive system, the relationship between the reference q-axis current and the speed of the PMSM is described in a second-order model. Next, a sliding mode surface with variable exponential coefficients is selected, and the expression of the controller is given. Then, the stability of the PMSM drive system is demonstrated by using Lyapunov functions. Using this method, the fixed-time convergence of the PMSM drive system can be realized and the occurrence of singularity phenomena can be avoided in a simpler and easier method. Finally, the effectiveness of the proposed method is verified by simulation and experimental results.

Fangchinoline Inhibits Cell Proliferation Via Akt/GSK-3beta/cyclin D1 Signaling and Induces Apoptosis in MDA-MB-231 Breast Cancer Cells

Wang, Chang-Dong,Yuan, Cheng-Fu,Bu, You-Quan,Wu, Xiang-Mei,Wan, Jin-Yuan,Zhang, Li,Hu, Ning,Liu, Xian-Jun,Zu, Yong,Liu, Ge-Li,Song, Fang-Zhou Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.2

Fangchinoline (Fan) inhibits cell proliferation and induces apoptosis in several cancer cell lines. The effects of Fan on cell growth and proliferation in breast cancer cells remain to be elucidated. Here, we show that Fan inhibited cell proliferation in the MDA-MB-231 breast cancer cell line through suppression of the AKT/Gsk-3beta/cyclin D1 signaling pathway. Furthermore, Fan induced apoptosis by increasing the expression of Bax (relative to Bcl-2), active caspase 3 and cytochrome-c. Fan significantly inhibited cell proliferation of MDA-MB-231 cells in a concentration and time dependent manner as determined by MTT assay. Flow cytometry analysis demonstrated that Fan treatment of MDA-MB-231 cells resulted in cell cycle arrest at the G1 phase, which correlated with apparent downregulation of both mRNA and protein levels of both PCNA and cyclin D1. Further analysis demonstrated that Fan decreased the phosphorylation of AKT and GSK-3beta. In addition, Fan up-regulated active caspase3, cytochrome-c protein levels and the ratio of Bax/Bcl-2, accompanied by apoptosis. Taken together, these results suggest that Fan is a potential natural product for the treatment of breast cancer.

Association of IgE-mediated allergen sensitivity and promoter polymorphisms of chemokine (C–C motif) ligand 5 gene in Han Chinese patients with allergic skin diseases

Ji-Chang Zhou,Yu-Mei Zhu,Zheng Chen,Shan He,Shi-jie Zheng,Jun-luan Mo,Xiao-Li Liu,Chun-mei Gong,Bin Hou,Hui Yang 한국유전학회 2015 Genes & Genomics Vol.37 No.5

Two single nucleotide polymorphisms (SNPs), rs2280788 (-28C[G) and rs2107538 (-403G[A), in the promoter region of chemokine (C–C motif) ligand 5 (CCL5) was reported to be involved in the immunoglobulin E (IgE) expression and IgE-mediated allergic reactions. This study was to investigate the characteristics of total serum IgE level, specific allergen sensitivities and the two SNPs in the allergic skin disease (ASD) patients. ASD patients visiting the dermatological outpatient department of a local hospital were included with certain criteria, and the fasting venous blood was sampled for analysis. Total serum IgE was assayed with an ELISA kit, and 14 kinds of allergen-specific IgE were tested with an allergen screening system. The polymerase chain reaction–restriction fragment length polymorphism method was used to analyze the two SNPs. Among the finally included 437 patients aged from 16 to 85 years, 68.2 % was positive for the total serum IgE, 49.2 % was positive for at least one of the assayed allergen-specific IgE, and 35.0 % was sensitive to house dust mite. In the SNPs analysis, the GG/(GA?AA) ratio and G/A ratio for the -403G[A locus in the male and/or female C45 years subgroup were significantly lower in the total serum IgE positive patients than in the negative patients (P\0.05). Weak linkage disequilibrium was found between -403A and -28C alleles in male subgroups adjusted by age. Conclusively, house dust mite was the most common allergen in ASD patients, and -403A allele of CCL5 promoter was a risk factor for IgE-mediated sensitization.

Removal of ozone from air by absorption in a rotating packed bed

Chia-Chang Lin,Cheng-Yu Chao,Mei-Yun Liu 한국공업화학회 2010 Journal of Industrial and Engineering Chemistry Vol.16 No.1

This work investigated the feasibility of ozone (O3) absorption by H2O2 solution in a rotating packed bed (RPB). The overall volumetric gas-phase mass transfer coefficients (KGa) were determined as functions of pH of H2O2 solution, O3 concentration, H2O2 concentration, RPB speed, gas flowrate, liquid flow rate, and RPB type. The KGa values were highly dependent on the pH of H2O2 solution. Also, the KGa values increased with O3 concentration and H2O2 concentration. As expected, the RPB speed positively affected the KGa values for all RPBs. Furthermore, the obtained results indicated that the KGa values increased as the inner radius of the bed was increased and the outer radius of the bed was decreased. Moreover, the KGa values increased with an increasing liquid flow rate and an increasing gas flow rate for all RPBs. The dependences of KGa on the gas flow rate and the liquid flow rate indicated that the resistance to mass transfer in the gas-phase for O3 absorption was higher than that in the liquid phase in the RPB.