A Highly Active Alpha Amylase from Bacillus Licheniformis: Directed Evolution, Enzyme Characterization and Structural Analysis

( Yi Han Liu ),( Shu Ai Fan ),( Xiao Guang Liu ),( Zhi Meng Zhang ),( Jian Ling Wang ),( Zheng Xiang Wang ),( Fu Ping Lu ) 한국미생물 · 생명공학회 2014 Journal of microbiology and biotechnology Vol.24 No.7

The stability of Bacillus licheniformis alpha-amylase (BLA) under acid condition was enhanced through direct evolution using the error-prone polymerase chain reaction. One beneficial mutation site, H281I, was obtained in BLA. The specific activity of H281I was 161/352 U/mg, which was 62.6/27.5% higher than that of the wild-type (WT) (99/276 U/mg) at pH 4.5/6.5 and 95°C. The pH optimum for H281I was decreased about 1 unit, whereas no significant changes of optimum temperature and thermostability were observed compared with the wild type (WT). The kcat/Km value of H281I was 1.7-/1.4-fold higher at pH 4.5/6.5, respectively, than that of WT. The structure model analysis indicated that the H281I mutation altered the predicted interaction between the amino acid residues at 281 and 273, thus creating a conducive local environment for substrate binding, as reflected by its decreased Km, and consequently increased the specific activity.

Research on the Strategy of Role Management Based on Grid Environment

Yi He LIU,Yu Ping QIN,Shuang ZHANG 보안공학연구지원센터 2016 International Journal of Security and Its Applicat Vol.10 No.2

The grid security affects directly the development of the grid and the practical application of grid system software. The access control is one of important contents of grid security research. The traditional access control models have ignored the subject security, and can not be solved with the dynamic grid, and the characteristics of the coexistence of multiple security strategy etc problems. Regarding expanded the concepts under the common network environment subject, the object, safe service, granularity control, the concept of subject/ object decomposition and the organization classifications are defined. Using the RBAC model and BLP the model basic principle, some of the new access control security strategy based on the grid environment has been defined in the paper. After discussion shows that the new rules emphasis on the subject security, and adapt to the dynamic nature of grid environment and characteristics of the coexistence of multiple security strategy. The new rules are compatibility with existing network access control model, they are secure and are also an expansion under the common network environment access control strategy, and this has certain positive significance to the grid security research.

Expression of IER3 in Primary Hepatocarcinoma: Correlation with Clinicopathological Parameters

Liu, Zhong,Wang, Xin-Mei,Jia, Tong-Fu,Zhai, Yi,Sun, Ling-Yan,Cheng, Yu-Ping,Zhang, Yue-Min,Liu, Shi-Hai,Liang, Jun Asian Pacific Journal of Cancer Prevention 2015 Asian Pacific journal of cancer prevention Vol.16 No.2

Background: Studies indicate the immediate early response gene 3 (IER3) is involved in many biological processes. Recently, it was discovered that IER3 plays an important role in tumorigenesis and tumor progression. Thus it may be a valuable biomarker in tumor. This study was designed to investigate the expression status of IER3 in primary hepatocarcinoma (PHC) and correlation with clinicopathological parameters. Materials and Methods: Real-time PCR was performed to evaluate the expression levels of IER3 in 62 pathologically diagnosed human PHC specimens. Results: A statistically significant association was disclosed between the expression of IER3 and P53 mutant protein (short for P53), Ki-67, EGFR and the biggest diameter, differentiation grade of tumor. Conclusions: This work is the first to shed light on the potential clinical usefulness of IER3, as an efficient tumor biomarker in PHC.

Dendritic Cells Induce Specific Cytotoxic T Lymphocytes against Prostate Cancer TRAMP-C2 Cells Loaded with Freeze-thaw Antigen and PEP-3 Peptide

Liu, Xiao-Qi,Jiang, Rong,Li, Si-Qi,Wang, Jing,Yi, Fa-Ping Asian Pacific Journal of Cancer Prevention 2015 Asian Pacific journal of cancer prevention Vol.16 No.2

Prostate cancer is the most common cancer in men. In this study, we investigated immune responses of cytotoxic T lymphocytes (CTLs) against TRAMP-C2 prostate cancer cells after activation by dendritic cells (DCs) loaded with TRAMP-C2 freeze-thaw antigen and/or PEP-3 peptide in vitro. Bone marrow-derived DC from the bone marrow of the C57BL/6 were induced to mature by using the cytokine of rhGM-CSF and rhIL-4, and loaded with either the freeze-thaw antigen or PEP-3 peptide or both of them. Maturation of DCs was detected by flow cytometry. The killing efficiency of the CTLs on TRAMP-C2 cells were detected by flow cytometry, CCK8, colony formation, transwell migration, and wound-healing assay. The levels of the IFN-${\gamma}$, TNF-${\beta}$ and IL-12 were measured by enzyme-linked immunosorbent assay (ELISA). Compared with the unloaded DCs, the loaded DCs had significantly increased expression of several phenotypes related to DC maturation. CTLs activated by DCs loaded with freeze-thaw antigen and PEP-3 peptide had more evident cytotoxicity against TRAMP-C2 cells in vitro. The secretion levels of IFN-${\gamma}$, TNF-${\beta}$ and IL-12, secreted by DCs loaded with antigen and PEP-3 and interaction with T cells, were higher than in the other groups. Our results suggest that the CTLs activated by DCs loaded with TRAMP-C2 freeze-thaw antigen and PEP-3 peptide exert a remarkable killing efficiency against TRAMP-C2 cells in vitro.

RNA m5C modification upregulates E2F1 expression in a manner dependent on YBX1 phase separation and promotes tumor progression in ovarian cancer

Liu Xiaoyi,Wei Qinglv,Yang Chenyue,Zhao Hongyan,Xu Jie,Mobet Youchaou,Luo Qingya,Yang Dan,Zuo Xinzhao,Chen Ningxuan,Yang Yu,Li Li,Wang Wei,Yu Jianhua,Xu Jing,Liu Tao,Yi Ping 생화학분자생물학회 2024 Experimental and molecular medicine Vol.56 No.-

5-Methylcytosine (m5C) is a common RNA modification that modulates gene expression at the posttranscriptional level, but the crosstalk between m5C RNA modification and biomolecule condensation, as well as transcription factor-mediated transcriptional regulation, in ovarian cancer, is poorly understood. In this study, we revealed that the RNA methyltransferase NSUN2 facilitates mRNA m5C modification and forms a positive feedback regulatory loop with the transcription factor E2F1 in ovarian cancer. Specifically, NSUN2 promotes m5C modification of E2F1 mRNA and increases its stability, and E2F1 binds to the NSUN2 promoter, subsequently reciprocally activating NSUN2 transcription. The RNA binding protein YBX1 functions as the m5C reader and is involved in NSUN2-mediated E2F1 regulation. m5C modification promotes YBX1 phase separation, which upregulates E2F1 expression. In ovarian cancer, NSUN2 and YBX1 are amplified and upregulated, and higher expression of NSUN2 and YBX1 predicts a worse prognosis for ovarian cancer patients. Moreover, E2F1 transcriptionally regulates the expression of the oncogenes MYBL2 and RAD54L, driving ovarian cancer progression. Thus, our study delineates a NSUN2-E2F1-NSUN2 loop regulated by m5C modification in a manner dependent on YBX1 phase separation, and this previously unidentified pathway could be a promising target for ovarian cancer treatment.

Functions of Membrane-bound Alcohol Dehydrogenase and Aldehyde Dehydrogenase in the Bio-oxidation of Alcohols in Gluconobacter oxydans DSM 2003

Liu-Jing Wei,Ji-lai Zhou,Dan-ni Zhu,Bai-yi Cai,Jin-Ping Lin,Qiang Hua,Dong-Zhi Wei 한국생물공학회 2012 Biotechnology and Bioprocess Engineering Vol.17 No.6

In this study a new insight was provided to understand the functions of membrane-bound alcohol dehydrogenase (mADH) and aldehyde dehydrogenase (mALDH) in the bio-oxidation of primary alcohols, diols and poly alcohols using the resting cells of Gluconobacter oxydans DSM 2003 and its mutant strains as catalyst. The results demonstrated that though both mADH and mALDH participated in most of the oxidation of alcohols to their corresponding acid, the exact roles of these enzymes in each reaction might be different. For example,mADH played a key role in the oxidation of diols to its corresponding organic acid in G. oxydans, but it was dispensable when the primary alcohols were used as substrates. In contrast to mADH, mALDH appears to play a relatively minor role in organic acid-producing reactions because of the possible presence of other isoenzymes. Aldehydes were, however, found to be accumulated in the mALDH-deficient strain during the oxidation of alcohols.

Resveratrol enhances the functionality and improves the regeneration of mesenchymal stem cell aggregates

Yi-Jing Wang,Pan Zhao,Bing-Dong Sui,Nu Liu,Cheng-Hu Hu,Ji Chen,Chen-Xi Zheng,An-Qi Liu,Kun Xuan,Ya-Ping Pan,Yan Jin 생화학분자생물학회 2018 Experimental and molecular medicine Vol.50 No.-

Mesenchymal stem cell (MSC)-based regeneration, specifically cell aggregate or cell sheet engineering, is a promising approach for tissue reconstruction. Considering the advantages of ease of harvest and lack of immune rejection, the application of autologous MSCs (i.e., patients’ own MSCs) in regenerative medicine has developed considerable interest. However, the impaired cell viability and regenerative potential following MSCs impacted by disease remain a major challenge. Resveratrol (RSV) exhibits reliable and extensive rejuvenative activities that have received increasing clinical attention. Here, we uncovered that resveratrol enhances the functionality and improves the regeneration of mesenchymal stem cell aggregates. Periodontal ligament MSCs (PDLSCs) from normal control subjects (N-PDLSCs) and periodontitis patients (P-PDLSCs) were investigated. Compared to N-PDLSCs, P-PDLSCs were less capable of forming cell aggregates, and P-PDLSC aggregates showed impaired osteogenesis and regeneration. These functional declines could be mimicked in N-PDLSCs by tumor necrosis factor alpha (TNF-α) treatment. Notably, a TNF-α-induced functional decline in N-PDLSC aggregates was rescued by RSV application. More importantly, in both N-PDLSCs and P-PDLSCs, RSV promoted cell aggregate formation and improved their osteogenic potential. Furthermore, as proven ectopically in vivo, the tissue regenerative capability of P-PDLSC aggregates was also enhanced after RSV treatment during aggregate formation in vitro. Finally, in a rat in situ regeneration model, we successfully applied both N-PDLSC aggregates and P-PDLSC aggregates to repair periodontal defects upon long-term functional improvements by RSV preconditioning. Together, our data unravel a novel methodology for using pharmacology (i.e., RSV)-based cell aggregate engineering to improve the functionality and facilitate the regeneration of MSCs from both healthy and inflammatory microenvironments, shedding light on improving the application of autologous MSC-mediated regenerative medicine.

Assembling Synthesis of Barium Chromate Nano-superstructures Using Eggshell Membrane as Template

Liu, Jin-Ku,Wu, Qing-Sheng,Ding, Ya-Ping,Yi, Yu Korean Chemical Society 2004 Bulletin of the Korean Chemical Society Vol.25 No.12

The branch-like, feather-like $BaCrO_4$ nano-superstructures were synthesized with bioactive eggshell membrane as directing and assembly template. Studies on the two products revealed that they formed through the self-assembly of nanoparticles, and that the optical properties of the products were different from $BaCrO_4$ bulk materials.

Application of Terahertz Spectroscopy and Imaging in the Diagnosis of Prostate Cancer

Ping Zhang,Shuncong Zhong,Junxi Zhang,Jian Ding,Zhenxiang Liu,Yi Huang,Ning Zhou,Walter Nsengiyumva,Tianfu Zhang 한국광학회 2020 Current Optics and Photonics Vol.4 No.1

The feasibility of the application of terahertz electromagnetic waves in the diagnosis of prostate cancer was examined. Four samples of incomplete cancerous prostatic paraffin-embedded tissues were examined using terahertz spectral imaging (TPI) system and the results obtained by comparing the absorption coefficient and refractive index of prostate tumor, normal prostate tissue and smooth muscle from one of the paraffin tissue masses examined were reported. Three hundred and sixty cases of absorption coefficients from one of the paraffin tissues examined were used as raw data to classify these three tissues using the Principal Component Analysis (PCA) and Least Squares Support Vector Machine (LS-SVM). An excellent classification with an accuracy of 92.22% in the prediction set was achieved. Using the distribution information of THz reflection signal intensity from sample surface and absorption coefficient of the sample, an attempt was made to use the TPI system to identify the boundaries of the different tissues involved (prostate tumors, normal and smooth muscles). The location of three identified regions in the terahertz images (frequency domain slice absorption coefficient imaging, 1.2 THz) were compared with those obtained from the histopathologic examination. The tissue tumor region had a distinctively visible color and could well be distinguished from other tissue regions in terahertz images. Results indicate that a THz spectroscopy imaging system can be efficiently used in conjunction with the proposed advanced computer-based mathematical analysis method to identify tumor regions in the paraffin tissue mass of prostate cancer.

Expression of Tumor Necrosis Factor-alpha-induced Protein 8 in Pancreas Tissues and its Correlation with Epithelial Growth Factor Receptor Levels

Liu, Ke,Qin, Cheng-Kun,Wang, Zhi-Yi,Liu, Su-Xia,Cui, Xian-Ping,Zhang, Dong-Yuan Asian Pacific Journal of Cancer Prevention 2012 Asian Pacific journal of cancer prevention Vol.13 No.3

Tumor necrosis factor (TNF)-alpha-induced protein 8 (TNFAIP8 or TIPE) is a recently identified protein considered to be associated with carcinogenesis. To investigate its expression pattern in pancreatic cancer patients and to analyse its correlation with clinicopathological significance and the expression levels of epithelial growth factor receptor (EGFR), immunohistochemistry was performed to detect the TNFAIP8 and EGFR proteins in pancreatic cancers, pancreatitis tissues, and healthy controls. The results showed stronger staining of TNFAIP8 protein in pancreatic cancer tissues compared with normal pancreas tissue. Furthermore, in 56 patients with pancreatic cancer, the expression levels of TNFAIP8 in patients with low tumor stage was higher than that with high tumor stage, and correlated with tumor staging and lymph node metastasis (P<0.05). Furthermore, TNFAIP8 expression positively correlated with EGFR levels (r=0.671135, P<0.05). These results indicate that TNFAIP8 may play important roles in the progression of pancreatic cancer.