检索结果-南通市图书馆

Recent advances in the chemical synthesis and semi-synthesis of poly-ubiquitin-based proteins and probes

在线全文

学校读者我要写书评

暂无评论

Science China Chemistry 2019年第3期62卷 299-312页

作者： Yun-Kun Qi Yan-Yan Si Shan-Shan Du Jun Liang Ke-Wei Wang Ji-Shen Zheng Department of Medicinal Chemistry School of Pharmacy Qingdao University Institute of Innovative Drugs Qingdao University School of Life Sciences University of Science and Technology of China State Key Laboratory Base for Eco-Chemical Engineering in College of Chemical Engineering Qingdao University of Science and Technology

Ubiquitination, a key and extensive posttranslational modification of proteins, has profound effects on a variety of physiological and pathological processes. The inherent complexity of ubiquitin conjugates makes it highly challenging to study the functional and structural mechanisms of ubiquitination. To address these challenges, accesses to sufficient poly-ubiquitin chains or ubiquitinated proteins are urgently needed. Over the last decade, synthetic protein chemists have developed several novel peptide ligation methods for the preparation of ubiquitin conjugates with precise control over the atomic structure. In this review, we summarize the recent breakthroughs and potential challenges in the chemical synthesis and semi-synthesis of ubiquitin conjugates with respect to the preparation of poly-ubiquitin-based proteins and ubiquitin-based probes.

关键词： ubiquitination poly-ubiquitin chains poly-ubiquitin-based proteins poly-ubiquitin-based probes chemical protein synthesis

Isolation of marine benzo[a]pyrene-degrading Ochrobactrum sp. BAP5 and proteins characterization

在线全文

学校读者我要写书评

暂无评论

Journal of Environmental Sciences 2009年第10期21卷 1446-1451页

作者： WU Yirui HE Tengteng ZHONG Mingqi ZHANG Yueling LI Enmin HUANG Tongwang HU Zhong Department of Biology Science College Shantou University Shantou 515063 China. Department of Biochemistry and Molecular Biology Medical College Shantou University Shantou 515063 China

A bacterial strain BAP5 with a relatively high degradation ability of benzo[a]pyrene （BaP） was isolated from marine sediments of Xiamen Western Sea, China and identified as Ochrobactrum sp. according to 16S rRNA gene sequence as well as Biolog microbial identification system. Strain BAP5 could grow in mineral salt medium with 50 mg/L of BaP and degrade about 20% BaP after 30 d of incubation. Ochrobactrum sp. BAP5 was able to utilize other polycyclic aromatic hydrocarbons （PAHs）（such as phenanthrene, pyrene and fluoranthene） as the sole carbon source and energy source, suggesting its potential application in PAHs bioremediation. The profile of total soluble protein from Ochrobactrum sp. BAP5 was also investigated. Some over- and special-expressed proteins of strain BAP5 when incubated with the presence of BaP were detected by two-dimensional polyacrylamide gel electrophoresis, and found to be related with PAHs metabolism, DNA translation, and energy production based on peptide fingerprint analysis through matrix-assisted laser desorption/ionization-time of flight mass spectrometry.

关键词： benzo[a]pyrene biodegradation Ochrobactrum sp. BAP5 proteins

The applications of nanopores in studies of proteins

在线全文

学校读者我要写书评

暂无评论

Science Bulletin 2019年第19期64卷 1456-1467页

作者： Taoli Ding Antony KChen Zuhong Lu Department of Biomedical Engineering College of EngineeringPeking UniversityBeijing100871China State Key Laboratory of Bioelectronics School of Biological Science and Medical EngineeringSoutheast UniversityNanjing210096China

Nanopores are a label-free platform with the ability to detect subtle changes in the activities of individual biomolecules under physiological ***,we comprehensively review the technological development of nanopores,focusing on their applications in studying the physicochemical properties and dynamic conformations of peptides,individual proteins,protein-protein complexes and protein-DNA *** is followed by a brief discussion of the potential challenges that need to be overcome before the technology can be widely accepted by the scientific *** believe that with continued refinement of the technology,significant understanding can be gained to help clarify the role of protein activities in the regulation of cellular physiology and pathogenesis.

关键词： Nanopores proteins Protein-protein interactions Protein-DNA interactions

Modeling hydrogen exchange of proteins by a multiscale method

在线全文

学校读者我要写书评

暂无评论

Chinese Physics B 2021年第7期30卷 93-99页

作者： Wentao Zhu Wenfei Li Wei Wang School of Physics National Laboratory of Solid State Microstructureand Collaborative Innovation Center of Advanced MicrostructuresNanjing UniversityNanjing 210093China

We proposed a practical way for mapping the results of coarse-grained molecular simulations to the observables in hydrogen change *** combining an atomic-interaction based coarse-grained model with an all-atom structure reconstruction algorithm,we reproduced the experimental hydrogen exchange data with reasonable accuracy using molecular dynamics *** also showed that the coarse-grained model can be further improved by imposing experimental restraints from hydrogen exchange data via an iterative optimization *** results suggest that it is feasible to develop an integrative molecular simulation scheme by incorporating the hydrogen exchange data into the coarse-grained molecular dynamics simulations and therefore help to overcome the accuracy bottleneck of coarse-grained models.

关键词： coarse-grained model hydrogen exchange multiscale method proteins integrative molecular simulations

Validation of a conductometric bienzyme biosensor for the detection of proteins as marker of organic matter in river samples

在线全文

学校读者我要写书评

暂无评论

Journal of Environmental Sciences 2009年第4期21卷 545-551页

作者： KHADRO Basma NAMOUR Philippe BESSUEILLE Franois LEONARD Didier JAFFREZIC-RENAULT Nicole University of Lyon Laboratory of AnalyticalCNRS UMR 5180 69622 Villeurbanne France Cemagref of Lyon

This article describes a conductometric bi-layer based bienzyme biosensor for the detection of proteins as a marker of organic matter in rivers. proteins were chosen to be used as indicators of urban pollution. The working mechanism of the bienzyme biosensor is based on the enzymatic hydrolysis of proteins into several fractions （peptides and amino acids）, which results in a local conductivity change depending of the concentration of proteins. In this work, we began with the optimization of biosensor response using bovine serum albumin （BSA） as standard protein. For this objective seven enzymatic biosensors were prepared： four enzymatic sensors with only one layer of enzyme （proteinase K, trypsin, pronase or protease X） and three other enzymatic sensors with two layers （first layer： membrane containing proteinase K; second layer： one of the three other enzymes： trypsin, pronase or protease X）. The biosensors were obtained through the deposition of enzymatic layers and the cross-linking process between enzymes and BSA in saturated glutaraldehyde vapour. The response of the various biosensors, described previously, were compared with the values of total organic carbon （TOC）, and those of organic nitrogen （No~）, as determined by the laboratory accredits （CEMAGREF of Lyon） using the traditional method of analysis （NF EN 1484, infrared spectroscopy） and （NF EN 25663, mineralization/colorimetry assay） respectively for each water sample obtained from different sites in Lyon （France）. The linear correlations obtained with the response of the seven biosensors showed the most important indices of correlations for the biosensor with two enzymatic layers： proteinase K ＋ pronase （pkp）. The optimum conditions for the preparation of the pkp biosensor increased the sensitivity and gave a limit of quantification of 0.583 μg/L for TOC and 0.218 μg/L for Norg in water samples. This sensor shows good reproducibility （2.28%）, a capacity to be used at temperatures range 10-- 30℃ （dependi

关键词： conductometric biosensor proteins enzyme natural water analyses total organic carbon organic nitrogen

Effect of proteins,polysaccharides,and particle sizes on sludge dewaterability

在线全文

学校读者我要写书评

暂无评论

Journal of Environmental Sciences 2009年第1期21卷 83-88页

作者： SHAO Liming,HE Peipei,YU Guanghui,HE Pinjing State Key Laboratory of Pollution Control and Resources Reuse,Key Laboratory of Yangtze River Water Environment,College of Environmental Science and Engineering,Tongji University,Shanghai 200092,China State Key Laboratory of Pollution Control and Resources Reuse Key Laboratory of Yangtze River Water Environment College of Environmental Science and Engineering Tongji University Shanghai 200092 China. E-mail: solidwaste@***

Four batch experiments of hydrolysis and acidification were carried out to investigate the distributions of proteins （PN） and polysaccharides （PS） in the sludge, the PN/PS ratio, the particle sizes, and their relationship with sludge dewaterability （as determined by capillary suction time, CST）. The sludge flocs were stratified through centrifugation- and ultrasound-based method into four fractions：（1） slime, （2） loosely bound extracellular polymeric substances （LB-EPS）, （3） tightly bound EPS （TB-EPS）, and （4） pellet. The results showed that PN was mainly partitioned in the pellet （80.7%） and TB-EPS （9.6%） fractions, while PS distributed evenly in the four fractions. During hydrolysis and acidification, PN was transferred from the pellet and TB-EPS fractions to the slime fraction, but PS had no significant transfer trends. The mean particle sizes of the sludge flocs decreased with hydrolysis and acidification. The pH had a more significant influence on the dewaterability of sludge flocs than temperature. Sludge dewaterability during hydrolysis and acidification processes greatly deteriorated from 9.7 s at raw sludge to 340-450 s under alkaline conditions. However, it was just slightly increased under acidic conditions. Further investigation suggested that CST was affected by soluble PN, soluble PN/PS, and particle sizes of sludge flocs, but was affected slightly by total PN, PS, or PN/PS in the whole sludge flocs and other fractions （except slime）.

关键词： dewaterability extracellular polymeric substances particle size polysaccharides proteins sewage sludge

Combining SAD/SIR iteration and MR iteration in partial-model extension of proteins

在线全文

学校读者我要写书评

暂无评论

Chinese Physics B 2010年第9期19卷 7-11页

作者：张涛武丽杰古元新郑朝德范海福 Research Institute of Magnetic Materials School of Physical Sciences and TechnologyLanzhou University Beijing National Laboratory for Condensed Matter Physics and Key Laboratory of Soft Matter Physics Institute of PhysicsChinese Academy of Sciences

There are two kinds of dual-space partial-model extensions which involve the direct-method program OASIS. The first kind, named SAD/SIR iteration, uses SAD/SIR information, while the second kind, named molecular replacement （MR） iteration, does not use that information. In general, the SAD/SIR iteration is more powerful since more experimental information is used. However, in most cases when protein structures are solved with the molecular replacement method, SAD/SIR information is not available. Thus the MR iteration is particularly useful for the completion of models from molecular replacement. The SAD/SIR iteration will be automatically used in OASIS for data sets containing SAD/SIR signals, while the MR iteration will be dedicated to data sets without SAD/SIR signals. The present paper shows that for data containing SAD/SIR signals, a combination of SAD/SIR iteration and MR iteration could lead to significantly better results than that obtained from the SAD/SIR iteration alone.

关键词： OASIS dual-space phasing model completion proteins

Multifunctional oral delivery systems for enhanced bioavailability of therapeutic peptides/proteins

在线全文

学校读者我要写书评

暂无评论

Acta Pharmaceutica Sinica B 2019年第5期9卷 902-922页

作者： Ying Han Zhonggao Gao Liqing Chen Lin Kang Wei Huang Mingji Jin Qiming Wang You Han Bae State Key Laboratory of Bioactive Substance and Function of Natural Medicines Department of PharmaceuticsInstitute of Materia MedicaChinese Academy of Medical Sciences and Peking Union Medical CollegeBeijing100050China Department of Pharmaceutics and Pharmaceutical Chemistry the University of UtahSalt Lake CityUT84108USA

In last few years, therapeutic peptides/proteins are rapidly growing in drug market considering their higher efficiency and lower toxicity than chemical drugs. However, the administration of therapeutic peptides/proteins is mainly limited in parenteral approach. Oral therapy which was hampered by harsh gastrointestinal environment and poorly penetrating epithelial barriers often results in low bioavailability(less than 1%–2%). Therefore, delivery systems that are rationally designed to overcome these challenges in gastrointestinal tract and ameliorate the oral bioavailability of therapeutic peptides/proteins are seriously promising. In this review, we summarized various multifunctional delivery systems, including lipid-based particles, polysaccharide-based particles, inorganic particles, and synthetic multifunctional particles that achieved effective oral delivery of therapeutic peptides/proteins.

关键词： Multifunctional delivery systems Oral Bioavailability Macromolecules Peptides and proteins Gastrointestinal environment Epithelial barriers Nanoparticles

Plant peroxisomal solute transporter proteins

在线全文

学校读者我要写书评

暂无评论

Journal of Integrative Plant Biology 2019年第7期61卷 817-835页

作者： Lennart Charton Anastasija Plett Nicole Linka Institute for Plant Biochemistry and Cluster of Excellence on Plant Sciences (CEPLAS) Heinrich Heine University

Plant peroxisomes are unique subcellular organelles which play an indispensable role in several key metabolic pathways, including fatty acid b-oxidation,photorespiration, and degradation of reactive oxygen species. The compartmentalization of metabolic pathways into peroxisomes is a strategy for organizing the metabolic network and improving pathway efficiency. An important prerequisite, however, is the exchange of metabolites between peroxisomes and other cell compartments. Since the first studies in the 1970s scientists contributed to understanding how solutes enter or leave this *** review gives an overview about our current knowledge of the solute permeability of peroxisomal membranes described in plants, yeast, mammals and other eukaryotes. In general, peroxisomes contain in their bilayer membrane specific transporters for hydrophobic fatty acids(ABC transporter) and large cofactor molecules(carrier for ATP, NAD and CoA). Smaller solutes with molecular masses below 300–400 Da, like the organic acids malate, oxaloacetate, and 2-oxoglutarate, are shuttled via non-selective channels across the peroxisomal *** comparison to yeast, human, mammals and other eukaryotes, the function of these known peroxisomal transporters and channels in plants are discussed in this review.

关键词： Plant peroxisomal solute transporter proteins