Aeromonas hydrophila cytosolic 5’-methylthioadenosine/S-adenosylhomocysteine nucleosidase MtaN-2

Jinli Chen,Fei Shang,Lulu Wang,Wei Liu,Yuanyuan Chen,Jing Lan,Liming Jin,Nam-Chul Ha,Chunshan Quan,Yongbin Xu 한국구조생물학회 2018 Biodesign Vol.6 No.3

5’-methylthioadenosine/S-adenosylhomocysteine nucleosidase (MTAN) plays a critical role in diverse pathways in bacterial cells such as biological methylation, polyamine biosynthesis, methionine recycling, and bacterial quorum sensing. It has been known that MtaN catalyzes the hydrolysis of N-ribosidic bond of adenosine-based substrates such as S-adenosyl-L-homocysteine (SAH), S-methyl-5’-thioadenosine (MTA) and 5’-deoxyadenosine (5’-DOA). In Aeromonas hydrophila, there are two MtnN subfamily proteins: MtaN-1, a periplasmic protein with an N-terminal signal peptide; and MtaN-2, a cytosolic protein. In this study, MtaN-2 from A. hydrophila was successfully expressed and purified using Ni-NTA affinity, Q anion-exchange, and gel-filtration chromatography. We first crystallized apo MtaN-2 but it diffracted to a low resolution of 5.1 Å. New crystals suitable for diffraction were obtained by adding 2 mM adenosine, a substrate analog of MtaN-2 during purification process and the crystals diffracted to the resolution of 2.0 Å. The crystals belong to the trigonal space group P31 or P32, with unit-cell parameters of a = b = 74.94 Å and c = 185.21 Å. The asymmetric unit contains four complexes of MtaN-2 with hydrolysis products of adenosine.

Corals from the Xiazhen Formation (Upper Ordovician), Zhuzhai, Yushan, SouthChina

Liming GUAN,Kun LIANG,Jusun Woo,Jino PARK,Dong-Chan LEE,Dong-Jin LEE 대한지질학회 2009 대한지질학회 학술대회 Vol.2009 No.

Post-fire Repair of Concrete Structural Members: A Review on Fire Conditions and Recovered Performance

Qiu, Jin,Jiang, Liming,Usmani, Asif Council on Tall Building and Urban Habitat Korea 2021 International journal of high-rise buildings Vol.10 No.4

Concrete structures may rarely collapse in fire incidents but fire induced damage to structural members is inevitable as a result of material degradation and thermal expansion. This requires certain repairing measures to be applied to restore the performance of post-fire members. A brief review on investigation of post-fire damage of concrete material and concrete structural members is presented in this paper, followed by a review of post-fire repair research regarding various types of repairing techniques (FRP, steel plate, and concrete section enlargement) and different type of structural members including columns, beams, and slabs. Particularly, the fire scenarios adopted in these studies leading to damage are categorized as three levels according to the duration of gas-phase temperature above 600℃ (t₆₀₀). The repair effectiveness in terms of recovered performance of concrete structural members compared to the initial undamaged performance has been summarized and compared regarding the repairing techniques and fire intensity levels. The complied results have shown that recovering the ultimate strength is achievable but the stiffness recovery is difficult. Moreover, the current fire loading scenarios adopted in the post-fire repair research are mostly idealized as constant heating rates or standard fire curves, which may have produced unrealistic fire damage patterns and the associated repairing techniques may be not practical. For future studies, the realistic fire impact and the system-level structural damage investigation are necessary.

Adiponectin Regulates Bone Marrow Mesenchymal Stem Cell Niche Through a Unique Signal Transduction Pathway: An Approach for Treating Bone Disease in Diabetes : Adiponectin Regulates BMSC Niche

Yu, Liming,Tu, Qisheng,Han, Qianqian,Zhang, Lan,Sui, Lei,Zheng, Leilei,Meng, Shu,Tang, Yin,Xuan, Dongying,Zhang, Jin,Murray, Dana,Shen, Qingping,Cheng, Jessica,Kim, Sung-Hoon,Dong, Lily Q.,Valverde, P Wiley (John WileySons) 2015 Stem Cells Vol.33 No.1

<P>Adiponectin (APN) is an adipocyte-secreted adipokine that exerts well-characterized antidiabetic properties. Patients with type 2 diabetes (T2D) are characterized by reduced APN levels in circulation and impaired stem cell and progenitor cell mobilization from the bone marrow for tissue repair and remodeling. In this study, we found that APN regulates the mobilization and recruitment of bone marrow-derived mesenchymal stem cells (BMSCs) to participate in tissue repair and regeneration. APN facilitated BMSCs migrating from the bone marrow into the circulation to regenerate bone by regulating stromal cell-derived factor (SDF)-1 in a mouse bone defect model. More importantly, we found that systemic APN infusion ameliorated diabetic mobilopathy of BMSCs, lowered glucose concentration, and promoted bone regeneration in diet-induced obesity mice. In vitro studies allowed us to identify Smad1/5/8 as a novel signaling mediator of APN receptor (AdipoR)-1 in BMSCs and osteoblasts. APN stimulation of MC3T3-E1 osteoblastic cells led to Smad1/5/8 phosphorylation and nuclear localization and increased SDF1 mRNA expression. Although APN-mediated phosphorylation of Smad1/5/8 occurred independently from adaptor protein, phosphotyrosine interaction, pleckstrin homology domain, and leucine zipper containing 1, it correlated with the disassembly of protein kinase casein kinase 2 and AdipoR1 in immunoprecipitation experiments. Taken together, this study identified APN as a regulator of BMSCs migration in response to bone injury. Therefore, our findings suggest APN signaling could be a potential therapeutic target to improve bone regeneration and homeostasis, especially in obese and T2D patients.</P>

Study on the combustion process and work capacity of a micro free-piston engine

Qian Wang,Liming Dai,Kai Wu,Jin Bai,Zhixia He 대한기계학회 2015 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.29 No.11

With the main idea of exploring combustion conditions and the work capacity of the micro free-piston engine, the study concern isvisualization work including Homogeneous charge compression ignition (HCCI) combustion in the micro-chamber. The initial freepistonvelocity was adjusted to achieve a wide range of compression ratio. The combustion characteristics, the piston motion and pressurevariations under different compression ratios were discussed. Results indicate that the critical combustion condition occurs when thecompression ratio rises to a certain degree. Two-stage combustion characteristics can be observed in micro HCCI combustion processeswith the fuel of the DME/oxygen mixture. The micro-chamber pressure increases with the increase of the compression ratio. The criticalpeak pressure of 5.4 MPa is obtained when the initial piston velocity reaches 15.0 m/s and the diameter and the length of the microchamberis 3 mm and 37 mm, respectively.

Study on Asymptotic Stability of Fractional Singular Systems with Time Delay

Dazi Li,Liming Wei,Tianheng Song,Qibing Jin 제어·로봇·시스템학회 2020 International Journal of Control, Automation, and Vol.18 No.4

The stability of fractional singular systems with time delay is discussed. Considering the singularity of the system, a system is decomposed into two subsystems. Through fractional Laplacian transformation and inverse Laplacian transformation on the subsystems, the expression of the state variables in time domain is obtained. According to the characteristics of Mittag-Leffler function, some inequalities that have important influence on stability are derived. Finally, a new sufficient condition is found to make the fractional singular systems with time delay asymptotically stable when the fractional order belongs to1 < α < 2. Meanwhile, the sufficient condition is also obtained to make the system stable under the nonlinear disturbance. All processes are proved and numerical examples are provided to show the validity and feasibility of the proposed method.

Bacillus amyloliquefaciens NAD+-dependent protein deacetylase: purification, crystallization and X-ray crystallographic analysis

Fei Shang,Jinli Chen,Lulu Wang,Yuanyuan Chen,Jing Lan,Wei Liu,Liming Jin,하남철,Chunshan Quan,Yongbin Xu 한국구조생물학회 2019 Biodesign Vol.7 No.1

Sirtuins are NAD+-dependent deacetylase that are broadly conserved throughout bacteria, archaea, and eukaryotes. Themembers of sirtuins are important in regulating diverse biological pathways, including gene silencing, DNA repair, genomestability, longevity, metabolism, and cell physiology. Sirtuin from Bacillus amyloliquefaciens (BaSrtN) is a particularlyinteresting bacterial Sir2 homologue. In this study, to further understand the function and mechanisms of this protein,BaSrtN was successfully expressed and purified using Ni-NTA affinity, Q anion-exchange, and gel-filtration chromatography. Purified BaSrtN was crystallized and diffracted to the resolution of 1.45 Å. The preliminary crystallographic analysissuggested that BaSrtN crystal belongs to the trigonal space group P31 or P32, with unit-cell parameters of a = b = 90.115and c = 86.306 Å. Size-exclusion chromatography suggested that BaSrtN prefer to exit as monomers in solution.

Security Data Auditing based on Multifunction Digital Watermark for Multimedia File in Cloud Storage

Yongjun Ren,Jian Shen,Jin Wang,JiangXu,Liming Fang 보안공학연구지원센터 2014 International Journal of Multimedia and Ubiquitous Vol.9 No.9

Crystal structure of the nicotinamidase/pyrazinamidase PncA from <i>Bacillus subtilis</i>

Shang, Fei,Chen, Jinli,Wang, Lulu,Jin, Liming,Zou, Linhai,Bu, Tingting,Dong, Yuesheng,Ha, Nam-Chul,Nam, Ki Hyun,Quan, Chunshan,Xu, Yongbin Elsevier 2018 Biochemical and biophysical research communication Vol.503 No.4

<P><B>Abstract</B></P> <P>The nicotinamidase/pyrazinamidase PncA is a member of a large family of hydrolase enzymes that catalyze the deamination of nicotinamide to nicotinic acid. PncA also functions as a pyrazinamidase in a wide variety of eubacteria and is an essential coenzyme in many cellular redox reactions in living systems. We report the crystal structure of substrate-free PncA from <I>Bacillus subtilis</I> (BsPncA) at 2.0 Å resolution to improve our understanding of the PncA family. The structure of BsPncA consists of an α/β domain and a subdomain. The subdomain of BsPncA has a different conformation than that of PncA enzymes from other organisms. The B-factor analysis revealed a rigid structure of the α/β domain, while the subdomain is highly flexible. Both dimers and tetramers were observed in BsPncA protein crystals, but only dimers were observed in solution. Our results provide useful information that will further enhance our understanding of the molecular functions of PncA family members.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Crystal structure of <I>B. Subtilis</I> PncA consists of an α/β domain and a subdomain. </LI> <LI> The metal-binding site of BsPncA is located at the bottom of a large cavity between the core and the subdomain. </LI> <LI> Zinc ion is pentahedrally coordinated within several highly conserved amino acid residues and one water molecule. </LI> <LI> Both dimers and tetramers were observed in BsPncA protein crystals, but only dimers were observed in solution. </LI> </UL> </P>

Family History and Stroke Risk in China: Evidence from a Large Cohort Study

Tian Tian,Guangfu Jin,Canqing Yu,Jun Lv,Yu Guo,Zheng Bian,Ling Yang,Yiping Chen,Hongbing Shen,Zhengming Chen,Zhibin Hu,Liming Li 대한뇌졸중학회 2017 Journal of stroke Vol.19 No.2

Background and Purpose Large cohort studies on relationship between family history of stroke(FHS) and stroke risk are lacking in Asians. We aimed to systematically evaluate the association ofFHS with stroke risk in a cohort study of 0.5 million Chinese adults. Methods Information about FHS was self-reported. The median follow-up time was 7.16 years andthe end-point of follow-up was incident stroke, which was entered directly into the China KadoorieBiobank system. Multivariate analyses were performed with Cox proportional hazards model, andinteraction analyses were carried using likelihood-ratio tests. Results Compared with participants without FHS, the hazard ratio (HR) (95% confidence interval,CI) of stroke for participants with FHS was 1.50 (1.46-1.55). The HRs increased with the number offirst degree relatives with stroke (HRs=1.41, 1.98 and 2.47 for 1, 2 and ≥3 relatives, respectively,Ptrend <0.001). The HRs were 1.57 (95% CI: 1.50-1.66) and 1.49 (95% CI: 1.45-1.54) for siblinghistory and parental history, respectively. Similar associations with offspring stroke risk wereobserved between paternal history (HR=1.48, 95% CI: 1.43-1.54) and maternal history (HR=1.49,95% CI: 1.43-1.55). Moreover, significant interactions were detected between FHS and health-riskbehaviors (tobacco smoking and alcohol drinking). Conclusions FHS is an independent risk factor for stroke in Chinese. The more first degree relativesare affected by stroke, the higher are individuals’ risk of suffering from stroke. The management ofthe health-risk behaviors for reducing stroke should be highlighted, especially for the individualswith FHS.