|
|
|
题名
|
作者
|
年代
|
出处
|
被引量
|
| 1 | Purification and Characterization of a New Thermostable κ-CarrageenasefromtheMarineBacterium Pseudoalteromonas sp. QY203显示文摘A new extracellular κ-carrageenase, namely CgkP, 34.0 kDa in molecular weight, was purified from Pseudoalteromonas sp. QY203. CgkP showed relatively high activity at acidities ranging from pH6.0 to pH9.0 and temperatures ranging from 30℃ to 50℃ with the highest activity at 45℃ and pH7.2. Sodium chloride increased its activity markedly, and KCl increased its activity slightly. The divalent and trivalent metal ions including Cu2+ , Ni2+ , Zn2+ , Mn2+ , Al3+ and Fe3+ significantly inhibited its activity, while Mg2+ did not. CgkP remained 70% of original activity after being incubated at 40℃ for 48 h, and remained 80% of the activity after being incubated at 45℃ for 1 h. It exhibited endo-κ-carrageenase activity, mainly depolymerizing the κ-carrageenan into disaccharide and tetrasaccharide. CgkP was more thermostable than most of previously reported κ-carrageenases with a potential of being used in industry. | LI Shangyong JIA Panpan WANG Linna YU Wengong HAN Feng | 2013 | Journal of Ocean University of China2013,12,1: | 10 |
| 2 | Cloning and Characterization of a New κ-Carrageenase Gene from Marine Bacterium Pseudoalteromonas sp. QY203显示文摘κ-carrageenan oligosaccharides exhibit various biological activities. Enzymatic degradation by κ-carrageenase is safe and controllable. Therefore, κ-carrageenases have captured more and more attentions. In this study, a κ-carrageenase encoding gene, cgk X, was cloned from Pseudoalteromonas sp. QY203 with degenerate and inverse PCR. It comprised an ORF of 1194 bp in length, encoding a protein with 397 amino acid residues. Cgk X is a new member of glycoside hydrolase family 16. The deduced amino acid sequence shared a high similarity with Cgk X of Pseudoalteromonas κ-carrageenase; however, the recombinant Cgk X showed different biochemical characteristics. The recombinant enzyme was most active at p H 7.0 and 55℃ in the presence of 300 mmol L^(^(-1))Na Cl. It was stable in a broad range of acidity ranging from p H 3.0 to p H 10.0 when temperature was below 40℃. More than 80% of its activity was maintained after being incubated at p H 3.6–10.0 and 4℃ for 24 h. Cgk X retained more than 90% of activity after being incubated at 40℃ for 1 h. EDTA and SDS(1 mmol L^(-1)) did not inhibit its activity. Cgk X hydrolyzed κ-carrageenan into disaccharide and tetrasaccharide as an endo-cleaver. All these characteristics demonstrated that Cgk X is applicable to both κ-carrageenan oligosaccharide production and κ-carrageenase structure-function research. | XU Xiaoyan LI Shangyong YANG Xuemei YU Wengong HAN Feng | 2015 | Journal of Ocean University of China2015,14,6: | 5 |
| 3 | Beamlet prestack depth migration and illumination: A test based on the Marmousi model显示文摘Beamlet 来源容易让强壮的本地、方向性的人物和罐头完成本地照明和移植。而且,他们比常规迁居方法提供更好的迁居结果。我们介绍让的横梁的基本原则包括窗口的 Fourier 变换和框架理论的 prestack 深度移植。我们基于 Gaussian 功能解释 Gabor-Daubechies (G-D ) 框架。Beamlet 分解在波浪地的本地空格和方向提供信息。我们综合横梁让来源和横梁在使用矩形和 Gaussian 窗口的小浪域让记录然后外推有一个 Fourier 有限差别的操作符的综合数据。我们用标准 Marmousi 模型测试方法。由比较并且分析让并且微笑的方向性的横梁与不同窗户和方向让的单身者的迁居结果,我们证明有 Gaussian 横梁的 prestack 深度迁居的有效性让方法。 | Ye Yueming Li Zhenchun Han Wengong Liu Qingmin | 2006 | Applied Geophysics2006,3,4: | 5 |
| 4 | Purification and Refolding of a Novel β-Agarase from Inclusion Body of E. coli显示文摘β-agarase AgaB appears to represent a new family of glycoside hydrolase; it is structurally and functionally different from other known agarases. In the present study, AgaB was expressed with a temperature-inducible expression system in E. coli BL21 (DE3) as a fusion protein bearing a C-terminal hexahistidine tag. The protein existed mainly in the form of inclusion body. After being washed and solubilized, AgaB in inclusion body was denatured and purified to electrophoretic purity by immobilized metal affinity chromatography. The purified AgaB was then refolded using a simple pulse dilution method, and the refolded AgaB showed a high specific hydrolysis activity of about 1600 units /mg protein. Forty milligrams of refolded pure protein were obtained from 1L of culture. | ZHANG Li, LU Xinzhi, HAN Feng, MA Cuiping, and YU Wengong* Marine Drug and Food Institute, Ocean University of China, Qingdao 266003, P.R. China | 2007 | Journal of Ocean University of China2007,6,1: | 1 |
| 5 | The hydrophobic cluster on the surface of protein is the key structural basis for the SDS-resistance of chondroitinase VhChlABC显示文摘The application of chondroitinase requires consideration of the complex microenvironment of the target.Our previous research reported a marine-derived sodium dodecyl sulfate(SDS)-resistant chondroitinase VhChlABC.This study further investigated the mechanism of VhChlABC resistance to SDS.Focusing on the hydrophobic cluster on its strong hydrophilic surface,it was found that the reduction of hydrophobicity of surface residues Ala181,Met182,Met183,Ala184,Val185,and Ile305 significantly reduced the SDS resistance and stability.Molecular dynamics(MD)simulation and molecular docking analysis showed that I305G had more conformational flexibility around residue 305 than wild type(WT),which was more conducive to SDS insertion and binding.The affinity of A181G,M182A,M183A,V185A and I305G to SDS was significantly higher than that of WT.In conclusion,the surface hydrophobic microenvironment composed of six residues was the structural basis for SDS resistance.This feature could prevent the binding of SDS and the destruction of hydrophobic packaging by increasing the rigid conformation of protein and reducing the binding force of SDS-protein.The study provides a new idea for the rational design of SDS-resistant proteins and may further promote chondroitinase research in the targeted therapy of lung diseases under the pressure of pulmonary surfactant. | Juanjuan Su Hao Wu Chengying Yin Fengchao Zhang Feng Han Wengong Yu | 2024 | Marine Life Science & Technology2024,6,1: | 0 |