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| 1 | Cementing mechanism of algal crusts from desert area显示文摘34-, 17-, 4-, 1.5-year old natural algal crusts were collected from Shapotou Scientific Station of the Chinese Academy of Sciences, 40-day old field and greenhouse artificial algal crusts were in situ developed in the same sandy soil and the same place (37°27’N, 104°57’E). Their different cohesions both against wind force and pressure were measured respectively by a sandy wind-tunnel experiment and a penetrometer. On the basis of these algal crusts, the cementing mechanism was revealed from many subjects and different levels. The results showed that in the indoor artificial crusts with the weakest cohesion bunchy algal filaments were distributed in the surface of the crusts, produced few extracellular polymers (EPS), the binding capacity of the crusts just accomplished by mechanical bundle of algal filaments. For field crusts, most filaments grew toward the deeper layers of algal crusts, secreted much more EPS, and when organic matter content was more than 2.4 times of chlorophyll a, overmuch organic | HU Chunxiang LIU Yongding ZHANG Delu HUANG Zebo B.S.Paulsen | 2002 | Chinese Science Bulletin2002，47，16： | 25 |
| 2 | Cyanobacteria-/cyanotoxin-contaminations and eutrophication status before Wuxi Drinking Water Crisis in Lake Taihu, China显示文摘After the appalling 'Wuxi Drinking Water Crisis', increasing investigations concerning the contaminations of cyanobacterial blooms and their toxins in Lake Taihu have been performed and reported in the last two years. However, information regarding these issues before the crisis in 2007 remained insufficient. To provide some background data for further comparisons, the present study reported our investigations conducted in 2004, associated with the cyanotoxin contaminations as well as the eutrophication status in Lake Taihu. Results from the one-year-study near a drinking water resource for Wuxi City indicated that, unlike the status in recent two years, cyanobacteria and chlorophyta are the co-dominance species throughout the year. The highest toxin concentration (34.2 ng/mL) in water columns occurred in August. In bloom biomass, the peak value of intracellular toxin (0.59 μg/mg DW) was determined in October, which was lag behind that in water column. In addition, MC-RR was the major toxin variant throughout the year. During the study period, nutrients levels of total nitrogen and phosphorus were also recorded monthly. Results from the present study will lead to a better understanding of the eutrophication status and the potential risks before 'Wuxi Drinking Water Crisis'. | Yongmei Liu Wei Chen Dunhai Li Zebo Huang Yinwu Shen Yongding Liu | 2011 | Journal of Environmental Sciences2011，23，4： | 19 |
| 3 | Percutaneous osteoplasty for extraspinal metastases显示文摘As an extension of percutaneous vertebroplasty(PVP), percutaneous osteoplasty(POP) refers broadly to percutaneous bone cement injected into various parts of the body and narrowly to cement injected into extraspinal bone lesions. POP mainly includes such surgeries as percutaneous sacroplasty, percutaneous acetabuloplasty, percutaneous femoral osteoplasty, and percutaneous iliac osteoplasty(Figure 1). Currently, POP is a positive and an effective treatment for extraspinal bone lesions in that it can rapidly relieve pain, effectively prevent pathological fractures, and partially inactivate tumors, with few complications. The aim of this review is to detail the POP techniques and report their safety and efficacy in the treatment of extraspinal metastases. | Qinghua Tian Yongde Cheng Chungen Wu | 2018 | Journal of Interventional Medicine2018，1，3： | 9 |
| 4 | Use of infrared thermal imaging to diagnose health of Ammopiptanthus mongolicus in northwestern China显示文摘Population of the rare and endangered species Ammopiptanthus mongolicus(Maxim.) Cheng f. declined rapidly in China's arid region and Central Asia. There is an urgent need to protect this species, which is particularly important in maintaining biodiversity throughout the arid region of northwestern China. By analyzing the infrared thermal images based on plant-transpiration transfer coefficient(h_at) and photosynthetic parameters, we made quantitative and accurate diagnoses of the plant growth and health status of A. mongolicus. Using an LI-COR6400 photosynthesis system, we measured the net photosynthetic rate(P_n), stomatal conductance(G_s), and transpiration rate(T_r). Infrared thermal images obtained in the field were processed by ENVI4.8 software to calculate surface temperatures of the plant subjects. We found that the plant transpiration transfer coefficient of A. mongolicus was in the order of old plants [young plants [intermediate-aged plants. Declining health levels of young, intermediate, and old plants were divided into three categories:\0.4, 0.4–0.7,and [0.7. The coefficient showed a significant negative correlation with T_r, G_s, and P_n, indicating that they can simultaneously reflect the state of plant growth. By establishing h_at and photosynthetic parameters in regression model Y = a-blnx, we can accurately diagnose plant growth and decline of plant health conditions. | Weijie Yuan Yi Yu Yongde Yue Ji Wang Fengchun Zhang Xiaohong Dang | 2015 | Journal of Forestry Research2015，26，3： | 5 |
| 5 | Serum osmolality and ions,and gill Na^(+)/K^(+)-ATPase of spottedtail goby Synechogobius ommaturus(R.)in response to acute salinity changes显示文摘This study was carried out to determine the effects of abrupt salinity change on osmoregulatory ability of the spottedtail goby Synechogobius ommaturus.720 juvenile fish(65.3±11.8 g)were transferred to 200 L tanks(with 40 juveniles in each tank),in which salinities were abruptly changed from 10 to 20,30,40,50 and freshwater.Survival rate,serum osmolality,electrolytes(Na^(+),Cl^(-),and K^(+))and gill Na^(+)/K^(+)-ATPase(NKA)activity were assessed successively in 528 h.Results showed serum osmolality,ion concentrations and gill Na^(+)/K^(+)-ATPase activity increased significantly when fish were transferred to salinity 40 and 50 and all fish in these groups died by the end of the experiment.Serum osmolality,Na^(+),Cl^(-)and K^(+)in fish transferred to a salinity of 20,30 and freshwater were not affected and no mortality was detected.Compared with the control group,a significantly decrease of NKA activity happened in the freshwater group,but the activity in 20 and 30 groups was not affected significantly.The results indicated that S.ommaturus could adapt rapidly and maintain homeostasis in a wide range of salinities(from freshwater to salinity 30)and this species may be suitable for aquaculture in estuarine and coastal areas where rapid salinity fluctuations commonly occur. | Chun Shui Yonghai Shi Xueming Hua Zhonghua Zhang Haiming Zhang Genhai Lu Yongde Xie | 2018 | Aquaculture and Fisheries2018，3，2： | 4 |
| 6 | 细胞生长因子在神经康复与神经可塑性中的研究进展显示文摘细胞生长因子是一类具有刺激细胞生长分裂活性的多肽类因子,具有广泛的生物学作用。细胞生长因子不仅调控机体生长发育等正常生理功能,还在神经损伤等病理过程中调节神经康复及神经可塑性,具体表现为促进神经元存活;促进神经再生,调节突触可塑性;促进细胞分化与血管再生,调节微环境;促进神经纤维髓鞘形成,改善神经传导。本文旨在探讨细胞生长因子在神经康复与神经可塑性中的作用机制和应用,以期提供细胞生长因子在康复领域的研究进展和在临床神经康复治疗中的应用前景。 | 李校堃 刘旭 刘建华 饶志恒 Yongde Luo 陈轲扬 张通 | 2022 | 中国康复理论与实践2022，28，2： | 4 |
| 7 | Preparation of 3D graphene-based architectures and their applications in supercapacitors显示文摘Three dimensional(3D) graphene-based architectures such as 3D graphene-based hydrogels,aerogels,foams,and sponges have attracted huge attention owing to the combination of the structural interconnectivities and the outstanding properties of graphene which offer these interesting structures with low density,high porosity,large surface area,stable mechanical properties,fast mass and electron transport.They have been extensively studied for a wide range of applications including capacitors,batteries,sensors,catalyst,etc.There are several reviews focusing on the 3D graphene-based architectures and their applications.In this work,we only summarise the latest development on the preparation of 3D graphene-based architectures and their applications in supercapacitors,with emphasis on the preparation strategies. | Zhuxian Yang Sakineh Chabi Yongde Xia Yanqiu Zhu | 2015 | Progress in Natural Science:Materials International2015，25，6： | 4 |
| 8 | New preparation of Mg-Li-Al alloys by electrolysis in molten salt显示文摘This work presents a study on electrochemical formation of Mg-Li-Al alloys on an inert electrode(Mo electrode) in a molten KCl-LiCl-AlCl3-MgCl2-KF system.It aims at preparation Mg-Li-Al metal alloy directly under an optimal electrolytic parameters.Main factors which affect current efficiency are investigated.We have discussed the co-electrodeposition conditions and the effect of technical parameters on these experiments,and gained a good electrolytic process.The result of calculation shows that co-electrodeposition Mg,Li and Al occurs at the cathode current density higher than 9 A/cm2 and electrolytic voltage between 6 to 9 V.And at the optimal parameters,12-13 A/cm2,620-640 ℃,the highest current effciency reaches as high as 86%.Lithium combined with magnesium forms Li0.92Mg4.08 and Li3Mg7,and aluminum mainly exists in a form of Mg0.58Al0.42,distributing in the alpha phases and beta phases. | Wei HAN Qiong CHEN Ke YE Yongde YAN Milin ZHANG | 2010 | Acta Metallurgica Sinica(English Letters)2010，23，2： | 3 |
| 9 | Surface functionalized N-C-TiO_(2)/C nanocomposites derived from metal-organic framework in water vapour for enhanced photocatalytic H generation显示文摘Surface-functionalized nitrogen/carbon co-doped polymorphic TiO_(2) phase junction nanoparticles uniformly distributed in porous carbon matrix were synthesized by a simple one-step pyrolysis of titanium based metal-organic framework(MOF),NH_(2)-MIL^(-1)25(Ti) at 700℃ under water vapour atmosphere.Introducing water vapour during the pyrolysis of NH_(2)-MIL^(-1)25(Ti) not only functionalizes the derived porous carbon matrix with carboxyl groups but also forms additional oxygen-rich N like interstitial/intraband states lying above the valence band of TiO2 along with the self-doped carbo n,which further narrows the energy band gaps of polymorphic TiO2 nanoparticles that enhance photocatalytic charge transfer efficiency.Without co-catalyst,sample N-C-TiO2/CArW demonstrates H_(2) evolution activity of 426 μmol gcat-1h^(-1),which remarkably outperforms commercial TiO_(2)(P-25) and N-C-TiO_(2)/CAr with a 5-fold and 3-fold H_(2) generation,respectively.This study clearly shows that water vapour atmosphere during the pyrolysis increases the hydrophilicity of the Ti-MOF derived composites by functionalizing porous carbon matrix with carboxylic groups,as well as enhancing the electrical conductivity and charge transfer efficiency due to the formation of additional localized oxygen-rich N like interstitial/intraband states.This work also demonstrates that by optimizing the anatase-rutile phase composition of the TiO2 polymorphs,tuning the energy band gaps by N/C co-doping and functionalizing the porous carbon matrix in the N-C-TiO2/C nanocomposites,the photocatalytic H_(2) generation activity can be further enhanced. | Mian Zahid Hussain Zhuxian Yang Bart van der Linden Zheng Huang Quanli Jia Erik Cerrato Roland A.Fischer Freek Kapteijn Yanqiu Zhu Yongde Xia | 2021 | Journal of Energy Chemistry2021，30，6： | 3 |
| 10 | Effect of the chlortetracycline addition method on methane production from the anaerobic digestion of swine wastewater显示文摘Effects of antibiotic residues on methane production in anaerobic digestion are commonly studied using the following two antibiotic addition methods:(1) adding manure from animals that consume a diet containing antibiotics, and(2) adding antibiotic-free animal manure spiked with antibiotics. This study used chlortetracycline(CTC) as a model antibiotic to examine the effects of the antibiotic addition method on methane production in anaerobic digestion under two different swine wastewater concentrations(0.55 and 0.22 mg CTC/g dry manure). The results showed that CTC degradation rate in which manure was directly added at 0.55 mg CTC/g(HSPIKE treatment) was lower than the control values and the rest of the treatment groups. Methane production from the HSPIKEtreatment was reduced(p < 0.05) by 12% during the whole experimental period and 15% during the first 7 days. The treatments had no significant effect on the pH and chemical oxygen demand value of the digesters, and the total nitrogen of the0.55 mg CTC/kg manure collected from mediated swine was significantly higher than the other values. Therefore, different methane production under different antibiotic addition methods might be explained by the microbial activity and the concentrations of antibiotic intermediate products and metabolites. Because the primary entry route of veterinary antibiotics into an anaerobic digester is by contaminated animal manure, the most appropriate method for studying antibiotic residue effects on methane production may be using manure from animals that are given a particular antibiotic, rather than adding the antibiotic directly to the anaerobic digester. | Lu Huang Xin Wen Yan Wang Yongde Zou Baohua Ma Xindi Liao Juanboo Liang Yinbao Wu | 2014 | Journal of Environmental Sciences2014，26，10： | 3 |
| 11 | Cell responses of Dunaliella salina FACHB 435 (Green Alga) to microgravitational stimulation by clinorotation显示文摘Clinorotation experiments were established to simulate microgravity on ground. It was found that there were obvious changes of Dunaliella salina FACHB435 cells and their metabolic characteristics during clinorotation. The changes included the increases of glycerol content, the rate of H + secretion and PM H + ATPase activity, and the decrease of ratio of the plasma membrane (PM) phospholipid to PM protein. These results indicated that microgravity was a stress environment to Dunaliella salina . It is deduced that it would be possible to attribute the effect of microgravity on algal cells to the secondary activation of water stress. | Zhangli Hu Yongding Liu | 1998 | Chinese Science Bulletin1998，43，20： | 3 |
| 12 | Metal-organic framework derived multi-functionalized and co-doped TiO_(2)/C nanocomposites for excellent visible-light photocatalysis显示文摘Multi-functionalized and co-doped TiO_(2)/C nanocomposites were derived from the pyrolysis of Ti-MOFs at 800℃under different gaseous atmospheres and their photocatalytic performance were investigated.The gaseous atmosphere during pyrolysis plays a critical role in determining the structural,textural,optical and physicochemical properties of the derived TiO_(2)/C composites due to the synergistic effect of nitrogen-containing species,carboxylate and sulfur functionalized porous carbon as well as N/S co-doped TiO_(2)nanoparticles.All the Ti-MOFs derived TiO_(2)/C composites exclusively possess homogeneously distributed TiO_(2)nanoparticles in a functionalized disc-like porous carbon matrix and demonstrate much enhanced adsorption and photodegradation performance than commercial TiO_(2)under the same conditions.The adsorption of methylene blue(MB)in dark on these TiO_(2)/C composites are dominated with pseudo second-order kinetic model and the high adsorption capacity of MB in dark on composite TiO_(2)/C derived from MIL-125(Ti)in argon is due to its high surface area with predominant mesoporous carbon matrix in the composite.The composite N-O-TiO_(2)/C derived from NH2-MIL-125(Ti)in water vapor exhibited the highest photodegradation activity with 99.7%MB removal in 3 h under visible light due to the optimal anatase/rutile phasejunction,together with the formation of photoactive oxygen-rich N-O like interstitial/intraband states above the valence band of TiO_(2),as well as the presence of N-containing species and-OH/-COOH multi-functional groups with superhydrophilic nature of the composite.This simple one-step and easily modifiable approach can be further employed to modulate homogeneously dispersed multi-functionalized and co-doped metal oxide/carbon nanocomposites for various environment and energy-related applications. | Mian Zahid Hussain Zhuxian Yang Ahmed M.E.Khalil Shahzad Hussain Saif Ullah Awan Quanli Jia Roland A.Fischer Yanqiu Zhu Yongde Xia | 2022 | Journal of Materials Science & Technology2022，，6： | 3 |
| 13 | Fossil bacteria in Xuanlong iron ore deposits of Hebei Province显示文摘Discovered in Early Proterozoic Xuanlong iron ore deposits are six genera of fossil iron bacteria, i. e. sphere (coenobium of) rod-shaped (monomer) Naumanniella, ellipsoid elliptical Ochrobium,sphere spherical Siderocapsa and chain spherical Siderococcus, chain rod-shaped Leptothrix and Lieskeella, and six genera of fossil blue bacteria, namely sphere spherical Gloeocapsa, Synechocystis and Globobacter, chain spherical Anabaena and Nostoc, and con-strictive septate tubular Nodularia. The biomineralized monomers and coenobia of the two cate-gories of bacteria, together with hematite plates made up the bacteria pelletal, bacteria silky, bacteria fibrous and clasty bacteria pelletal textural lamina. The bacteria pelletal laminae com-bined with other bacteria laminae to make up oncolite, stromatolite and laminate. The precipita-tion of iron oxide was accelerated due to iron and blue bacteria cohabiting on microbial film or mat. The Xuanlong iron ore deposits are microbial binding ore deposits of ocean source. | DAI Yongding, SONG Haiming & SHEN Jiying Institute of Geology and Geophysics, Chinese Academy of Sciences,Beijing 100029, China | 2004 | Science China Earth Sciences2004，47，4： | 3 |
| 14 | Electrochemical Preparation of Mg-Li-Al-Er Alloys by Co-reduction in Molten Chloride显示文摘The electrochemical behavior of Mg,Li,Al and Er were investigated by electrochemical techniques in LiClKCl-MgCl2-AlCl3-ErCl3 melts at 823 K.The cyclic voltammetry and chronopotentiometry indicated that the co-reduction of Mg,Li,Al and Er occurs at current densities more negative than-0.89 A.cm-2.Er(III) under-potential deposited on pre-reduced Al electrode formed Al-RE alloys.X-ray diffraction(XRD) results indicated that Mg17Al12,Al2Er,Al2Er3 and Al4Li9 phases were prepared by galvanostatic electrolysis.ICP analyses of samples showed that lithium and aluminum contents of Mg-Li-Al-Er alloys could be controlled by concentration of AlCl3 and cathodic current density. | Yi SUN Milin ZHANG Wei HAN Mei LI Yusheng YANG Yongde YAN Meng ZHANG | 2013 | Acta Metallurgica Sinica(English Letters)2013，26，4： | 3 |
| 15 | Improving photosynthesis of microalgae by changing the ratio of light-harvesting pigments显示文摘Changing the ratio of light-harvesting pigments was regarded as an efficient way to improve the photosyn-thesis rate in microalgae, but the underlying mechanism is still unclear. In the present study, a mutant of Anabeana simensis (called SP) was selected from retrieved satellite cul-tures. Several parameters related with photosynthesis, such as the growth, photosynthesis rate, the content of photosyn-thetic pigment, low temperature fluorescence spectrum (77K) and electron transport rate, were compared with those of the wild type. It was found that the change in the ratio of light-harvesting pigments in the mutant led to more efficient light energy transfer and usage in mutant than in the wild type. This may be the reason why the mutant had higher photosynthesis and growth rates. | WANG Gaohong CHEN Lanzhou LI Genbao LI Dunhai HU Chunxiang CHEN Haofeng LIU Yongding SONG Lirong | 2005 | Chinese Science Bulletin2005，50，15： | 3 |
| 16 | A GPU-based numerical model coupling hydrodynamical and morphological processes显示文摘Sediment transport simulations are important in practical engineering.In this study,a graphics processing unit(GPU)-based numerical model coupling hydrodynamical and morphological processes was developed to simulate water flow,sediment transport,and morphological changes.Aiming at accurately predicting the sediment transport and sediment scouring processes,the model resolved the realistic features of sediment transport and used a GPU-based parallel computing technique to the accelerate calculation.This model was created in the framework of a Godunov-type finite volume scheme to solve the shallow water equations(SWEs).The SWEs were discretized into algebraic equations by the finite volume method.The fluxes of mass and momentum were computed by the Harten,Lax,and van Leer Contact(HLLC) approximate Riemann solver,and the friction source terms were calculated by the proposed a splitting point-implicit method.These values were evaluated using a novel 2 D edge-based MUSCL scheme.The code was programmed using C++and CUDA,which could run on GPUs to substantially accelerate the computation.The aim of the work was to develop a GPU-based numerical model to simulate hydrodynamical and morphological processes.The novelty is the application of the GPU techniques in the numerical model,making it possible to simulate the sediment transport and bed evolution in a high-resolution but efficient manner.The model was applied to two cases to evaluate bed evolution and the effects of the morphological changes on the flood patterns with high resolution.This indicated that the GPU-based high-resolution hydro-geomorphological model was capable of reproducing morphological processes.The computational times for this test case on the GPU and CPU were298.1 and 4531.2 s,respectively,indicating that the GPU could accelerate the computation 15.2 times.Compared with the traditional CPU high-grid resolution,the proposed GPU-based high-resolution numerical model improved the reconstruction speed more than 2.0-12.83 times for different grid resolutions while remaining computationally efficient. | Jingming Hou Yongde Kang Chunhong Hu Yu Tong Baozhu Pan Junqiang Xia | 2020 | International Journal of Sediment Research2020，35，4： | 3 |
| 17 | Construction of hydrangea-like core-shell SiO_(2)@Ti_(3)C_(2)T_(x)@CoNi microspheres for tunable electromagnetic wave absorbers显示文摘Ti_(3)C_(2)T_(x)MXene shows great potential in the application as microwave absorbers due to its high attenuation ability.However,excessively high permittivity and self-stacking are the main obstacles that constrain its wide range of applications.To tackle these problems,herein,the microspheres of SiO_(2)@Ti_(3)C_(2)T_(x)@CoNi with the hydrangea-like core-shell structure were designed and prepared by a combinatorial electrostatic assembly and hydrothermal reaction method.These microspheres are constructed by an outside layer of CoNi nanosheets and intermediate Ti_(3)C_(2)T_(x)MXene nanosheets wrapping on the core of modified SiO_(2),engendering both homogenous and heterogeneous interfaces.Such trilayer SiO_(2)@Ti_(3)C_(2)T_(x)@CoNi microspheres are“magnetic microsize supercapacitors”that can not only induce dielectric loss and magnetic loss but also provide multilayer interfaces to enhance the interfacial polarization.The optimized impedance matching and core-shell structure could boost the reflection loss(RL)by electromagnetic synergy.The synthesized SiO_(2)@Ti_(3)C_(2)T_(x)@CoNi microspheres demonstrate outstanding microwave absorption(MA)performance benefited from these advantages.The obtained RL value was-63.95 dB at an ultra-thin thickness of 1.2 mm,corresponding to an effective absorption bandwidth(EAB)of 4.56 GHz.This work demonstrates that the trilayer core-shell structure designing strategy is highly efficient for tuning the MA performance of MXene-based microspheres. | Huanhuan Niu Xuewen Jiang Yongde Xia Hailong Wang Rui Zhang Hongxia Li Bingbing Fan Yanchun Zhoua | 2023 | Journal of Advanced Ceramics2023，12，4： | 3 |
| 18 | Identification of Oblate Band in Odd-odd ^(184)Au显示文摘The high-spin states in 184Au were populated by using the 159Tb( 29Si, 4ng) 184Au reaction at a bombarding energy of 140 MeV. The 29Si beam of 8 pnA was provided by the accelerator complex of the Tandem-XTU and ALPI at the Laroratori Nazionale di Legnero, Italy, and focussed onto a natural metallic 159Tb foil | Zhang Yuhu Wang Hualei G. de Angelis N. Maiginean A. Gadea D. R. Napoli M. Axiotis C. R.usu T. Martinez Zhou Xiaohong Fang Yongde Guo Wentao Liu Minliang Lei Xiangguo Guo Yingxiang | 2004 | 近代物理研究所和兰州重离子加速器实验室年报:英文版2004，，1： | 2 |
| 19 | Preparation of ternary Mg-Li-Sn alloys from molten salt by electrolysis显示文摘Electrochemical behavior of Mg,Li and Sn on tungsten electrodes in LiCl-KCl-MgCl2SnCl2 melts at 873 K was investigated.Cyclic voltammograms(CVs) showed that the underpotential deposition(UPD) of magnesium on pre-deposited tin leads to the formation of a Mg-Sn alloy,and the succeeding underpotential deposition of lithium on pre-deposited Mg-Sn alloy leads to the formation of a Mg-Li-Sn alloy.Chronopotentiometric measurements indicated that the codepositon of Mg,Li and Sn occurs at current densities more negative than-1.16 A.cm 2.X-ray diffraction(XRD) indicated that Mg2Sn phase is formed via galvanostatic electrolysis.The element Mg distributes homogeneously and Sn locates mainly on the grain boundaries in the MgLi-Sn alloy. | Peng CAO Milin ZHANG Wei HAN Yongde YAN Lijun CHEN | 2012 | Acta Metallurgica Sinica(English Letters)2012，25，4： | 2 |
| 20 | Structural basis of heparan sulfate-specific degradation by heparinase Ⅲ显示文摘Heparinase Ⅲ(HepⅢ)is a 73-kDa polysaccharide lyase(PL)that degrades the heparan sulfate(HS)polysaccharides at sulfate-rare regions,which are important co-factors for a vast array of functional distinct proteins including the well-characterized antithrombin and the FGF/FGFR signal transduction system.It functions in cleaving metazoan heparan sulfate(HS)and providing carbon,nitrogen and sulfate sources for host microorganisms.It has long been used to deduce the structure of HS and heparin motifs;however,the structure of its own is unknown.Here we report the crystal structure of the HepⅢ from Bacteroides thetaiotaomicron at a resolution of 1.6Å.The overall architecture of HepⅢ belongs to the(α/α)5 toroid subclass with an N-terminal toroid-like domain and a C-terminal β-sandwich domain.Analysis of this high-resolution structure allows us to identify a potential HS substrate binding site in a tunnel between the two domains.A tetrasaccharide substrate bound model suggests an elimination mechanism in the HS degradation.Asn260 and His464 neutralize the carboxylic group,whereas Tyr314 serves both as a general base in C-5 proton abstraction,and a general acid in a proton donation to reconstitute the terminal hydroxyl group,respectively.The structure of HepⅢ and the proposed reaction model provide a molecular basis for its potential practical utilization and the mechanism of its eliminative degradation for HS polysaccarides. | Wei Dong Weiqin Lu Wallace L.McKeehan Yongde Luo Sheng Ye | 2012 | Protein & Cell2012，3，12： | 2 |
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