共查询到20条相似文献,搜索用时 15 毫秒
1.
石墨烯是碳材料家族新兴成员之一,因其具有化学性质稳定、良好生物兼容性、催化性、零带隙、特殊的电子能带等特点而受到科学家们广泛关注。 石墨烯特殊的六元环基底平面对很多分子、离子具有亲和性,可通过非共价键或共价键将目标物质富集于表面,大多数情况下被吸附的物质在特定条件下易解吸且不会引起其结构和性质的改变。 石墨烯因而在生物成像、生物医学、光催化、生物传感、药物载体和释放、 环境等方面应用前景广阔。 本文主要论述石墨烯和它的衍生物在生命大分子( 蛋白质和核酸) 分析化学方面的应用,并展望了其发展趋势。 相似文献
2.
3.
非天然生物大分子超材料是一种具有独特化学结构和功能特性的材料,其功能可能超越自然界中存在的生物大分子,已成为高分子科学领域的研究前沿。这类材料可以被人为地设计与改造,通过(动态)化学修饰、基因工程和超分子自组装技术制备而得,从而拥有超常的光学、电子和机械性能,以及优异的灵活性、响应性、可控性和多样性。因此,非天然生物大分子超材料在生物、医学和材料等领域具有广阔的应用前景。基于此,本文综述了非天然生物大分子超材料的设计及合成方法,并总结了它们在生物传感、催化、医药和纳米材料等多个领域的具体应用,着重强调了它们在解决不同领域复杂问题中的重要性。 相似文献
4.
高效离子交换色谱法分离和纯化蛋白质时,蛋白质在色谱柱上的不可逆吸附使柱效降低,柱压升高。本文使用2%的胰蛋白酶溶液在37℃下处理TSKgelCM-5PW和TSKgelDEAE-5PW(7×7.5mmI.D.)离子交换色谱柱24h后,柱压显著降低,柱效提高4~13倍,交换容量也得到恢复。离子交换色谱柱的恢复程度和交换容量与处理液的用量有关。 相似文献
5.
Mesoporous carbons containing cobalt nanoparticles are synthesized by tri-or quad-constituent self assembly of Pluronic F127, phenol-formaldehyde oligomer (resol), cobalt acetylacetonate (acac), and optionally tetraethyl orthosilicate (TEOS, optional). Upon pyrolysis in N2 atmosphere, the resol provides sufficient carbon yield to maintain the ordered structure, while decomposition of the Co(acac) yields cobalt nanoparticles. To provide increased surface area, the dispersed silicate from condensation of TEOS can be etched after carbonization to yield micropores, Without silica templated micropores, the surface area decreases as the cobalt content increases, but there is a concurrent increase in the volume-average pore diameter (BHJ) and a dramatic increase in the adsorption capacity of methylene green with the equilibrium adsorption capacity from 2 to 90 mg/g with increasing Co content. Moreover, the surface area and pore size of mesoporous composites can be dramatically increased by addition of TEOS and subsequent etching. These composites exhibit extremely high adsorption capacity up to 1151 mg/g, which also increases with increases in the Co content. Additionally, the inclusion of cobalt nanoparticles provides magnetic separation from aqueous suspension. The in situ synthesis of the Co nanoparticles yields to a carbon shell that can partially protect the Co from leaching in acidic media; after 96 h in 2 M HCl, the powders remain magnetic. 相似文献
6.
Dr. Qing Liu Yuanyu Huang Prof. Lele Li Prof. Zhengping Li Mengyuan Li 《Angewandte Chemie (International ed. in English)》2023,62(18):e202214958
Precise regulation of protein activity and localization in cancer cells is crucial to dissect the function of the protein-involved cellular network in tumorigenesis, but there is a lack of suitable methodology. Here we report the design of enzyme-operated spherical nucleic acids (E-SNAs) for manipulation of the nucleocytoplasmic translocation of proteins with cancer-cell selectivity. The E-SNAs are constructed by programmable engineering of aptamer-based modules bearing enzyme-responsive units in predesigned sites and further combination with SNA nanotechnology. We demonstrate that E-SNAs are able to regulate cytoplasmic-to-nuclear shuttling of RelA protein efficiently and specifically in tumor cells, while they remain inactive in normal cells due to insufficient enzyme expression. We further confirmed the generality of this strategy by investigating the enzyme-modulated inhibition/activation of thrombin activity by varying the aptamer-based design. 相似文献
7.
Akemi Yamaguchi Kazuyuki Matsuda Masayuki Uehara Takayuki Honda Yasunori Saito 《Analytica chimica acta》2016
We report a novel automated device for nucleic acid extraction, which consists of a mechanical control system and a disposable cassette. The cassette is composed of a bottle, a capillary tube, and a chamber. After sample injection in the bottle, the sample is lysed, and nucleic acids are adsorbed on the surface of magnetic silica beads. These magnetic beads are transported and are vibrated through the washing reagents in the capillary tube under the control of the mechanical control system, and thus, the nucleic acid is purified without centrifugation. The purified nucleic acid is automatically extracted in 3 min for the polymerase chain reaction (PCR). The nucleic acid extraction is dependent on the transport speed and the vibration frequency of the magnetic beads, and optimizing these two parameters provided better PCR efficiency than the conventional manual procedure. There was no difference between the detection limits of our novel device and that of the conventional manual procedure. 相似文献
8.
通过4步化学反应对磁性Fe3O4@Si02纳米粒子进行化学修饰,设计和制备了一种N,N’-二(5-四唑亚甲基)胺修饰的金属螯合磁性纳米粒子.用X射线光电子能谱(XPS)、Zeta电位对该新型吸附剂进行了表征.用静态吸附法研究了螯合Cu(Ⅱ)吸附剂对溶菌酶、细胞色素C和α-糜蛋白酶的吸附性能以及溶液pH值、盐浓度、蛋白初始浓度对吸附量的影响.结果表明,吸附剂对蛋白质的吸附主要通过金属配位机理进行,且符合Langmuir吸附模型,对溶菌酶、细胞色素C和α-糜蛋白酶的最大吸附量分别20.0、13.5和17.9 mg/g.此外,将螯合Cu(Ⅱ)吸附剂用于混合蛋白质样品的吸附,发现此吸附剂对混合蛋白质样品中的溶菌酶具有选择性吸附作用,说明此金属螯合吸附剂在蛋白质选择性分离富集中具有一定应用价值. 相似文献
9.
Magnetic photocatalytic Fe3O4@TiO2 composites have been fabricated by changing the concentration of (NH2)2CO. Samples were named as low (NH2)2CO concentration group which the (NH2)2CO concentration in the synthesis process was below 2.25 mol/L and high (NH2)2CO concentration group which the (NH2)2CO concentration was above 2.5 mol/L. Photocatalytic degradation experiments of methyl orange showed that the final degradation rates of low (NH2)2CO concentration group samples were higher than that of high (NH2)2CO concentration group, even better than P25 at the same test conditions. And it was interesting that samples of low (NH2)2CO concentration group had smaller values of BET surface areas than that of high (NH2)2CO concentration group. It indicated that the improvement of photocatalytic activity which was effected by BET surface areas was not obvious. There were two main factors enhancing the photocatalytic property of low (NH2)2CO concentration group: First, diffusing reflection spectra showed that the low (NH2)2CO concentration group samples had lower reflectivity, this suggested that the structure improved the efficiency of light absorption; Second, NH4+ would take up the active sites on the surface of the TiO2 particles, the FT-IR test results showed that the samples of the low (NH2)2CO concentration group samples bonded less NH4+, thus leading to the higher photocatalytic activity. It had enlightenment role for optimizing the performance of photocatalytic materials. 相似文献
10.
Glycoproteins are useful biomarkers and therapeutic targets for a number of diseases, including infections and cancer. However, identification and isolation of low‐abundant glycoproteins remains a significant challenge that limits their application. Thus, methods of specific and selective glycoprotein enrichment are required. In this study, novel phenylboronic acid functionalized magnetic microspheres were successfully synthesized. Fe3O4 microspheres were synthesized by using a hydrothermal method and were coated with tetraethyl orthosilicate using an ultrasonic method to form a core‐shell structure. Compared to the conventional mechanical stirring for 12 h, the ultrasonic method saved about 7 h in processing time, and the home‐made magnetic microspheres had better dispersibility and homogeneity. Subsequently, the magnetic microspheres were modified by addition of an amino group and a carboxyl group, in sequence. Finally, 3‐aminophenylboronic acid, as the functional monomer, was linked to the magnetic microspheres for capturing glycoprotein/glycopeptides. The results of this study indicate that phenylboronic acid functionalized magnetic microspheres show excellent adsorption performance toward glycoprotein/glycopeptides. The maximum absorbing capacity of the microspheres for fetuin was 108 mg/g, and the enrichment efficiency reached 89.7%, indicating their potential to separate and enrich glycoproteins from the complex biological samples. 相似文献
11.
The ability to recover and purify natural and recombinant proteins, and the costs of doing so remain a major task in introducing
the potential products of biotechnology. The bases for separation range from specific binding onto tailored reagents to solubility
and partitioning behavior governed by a mixed bag of size, charge, and hydrophobicity. In most cases, a combination of methods
is used in sequence, and improvements in the selectivity at an early stage can enhance the effectiveness of subsequent (and
usually more costly) steps. Genetic engineering provides a means of improving the selectivity within the context of existing
separation methods.
By this strategy, improvements in selectivity are sought by bestowing a distinctive property on the protein of interest. The
primary sequence of amino acids is altered, such that the protein can be selectively removed from other components of the
multicomponent mixture in which such products are commonly found. In this article, the range of these “distinctive properties”
and their pairing with various separation methods will be reviewed. Specific examples from our work, in which a distinctive
charge is provided via a polypeptide “purification” fusion tail, will be discussed. Separation methods we have used with these
fusion proteins are precipitation, two-phase aqueous extraction, reversed micellar extraction, and ion exchange using both
resins and membranes. 相似文献
12.
Integration of carboxyl modified magnetic particles and aqueous two-phase extraction for selective separation of proteins 总被引:1,自引:0,他引:1
Both of the magnetic particle adsorption and aqueous two-phase extraction (ATPE) were simple, fast and low-cost method for protein separation. Selective proteins adsorption by carboxyl modified magnetic particles was investigated according to protein isoelectric point, solution pH and ionic strength. Aqueous two-phase system of PEG/sulphate exhibited selective separation and extraction for proteins before and after magnetic adsorption. The two combination ways, magnetic adsorption followed by ATPE and ATPE followed by magnetic adsorption, for the separation of proteins mixture of lysozyme, bovine serum albumin, trypsin, cytochrome C and myloglobin were discussed and compared. The way of magnetic adsorption followed by ATPE was also applied to human serum separation. 相似文献
13.
Currently, small proteins imprinting are more reported since large proteins molecular imprinting faces challenge due to their bulk size and complex structure. In this work, bovine serum albumin (BSA) surface-imprinted magnetic polymer was successfully synthesized based on atomic transfer radical polymerization (ATRP) method in the presence of common monomer (N-isopropylacrylamide) with the assistant of basic functional monomer (N-[3-(dimethylamino)propyl]-methacrylamide), which provides a achievable attempt for imprinting larger target proteins based on the ATPR with the mild reaction conditions. The BSA-imprinted polymer exhibited higher adsorption capacity and selectivity to BSA over the non-imprinted polymer. Competitive adsorption tests indicated the BSA-imprinted polymer had better selective adsorption and recognition properties to BSA in the mixture. The obtained BSA-imprinted polymer was applied to bovine serum, which also showed selectivity to BSA. In addition, a conventional aqueous two-phase solution of PEG/sulphate was used as elution for adsorbed BSA, which was compared with common NaCl elution. 相似文献
14.
Leonid Breydo 《Tetrahedron letters》2004,45(29):5711-5716
A series of compounds related to the macrocyclic portion of the DNA-damaging antitumor agent leinamycin were prepared as tools to characterize noncovalent DNA binding by this natural product. Acyclic (Z,E)-dienes were assembled via a Sonogashira coupling followed by partial hydrogenation. A Stille coupling was used in the cyclization step leading to a macrocyclic thiazole-diene analogue. Results obtained using the synthetic analogues reported here indicate that the extended π-system on the `left-hand side' of leinamycin is required for noncovalent association of the natural product with duplex DNA. 相似文献
15.
Antibiotics as inhibitors of nucleic acid and protein synthesis 总被引:2,自引:0,他引:2
G Hartmann W Behr K A Beissner K Honikel A Sippel 《Angewandte Chemie (International ed. in English)》1968,7(9):693-701
The antibiotics of the rifamycin, actinomycin, chromomycin, and anthracycline groups have been found to be specific inhibitors for the DNA-controlled synthesis of RNA in vitro. Streptomycin, chloramphenicol, and puromycin can specifically suppress certain steps in the biosynthesis of proteins. The investigation of the mode of action of such substances may help us to gain a better insight into the transmission of hereditary information. 相似文献
16.
合成了Co@SiO2核壳式纳米粒子,并采用透射电镜(TEM)、X射线衍射(XRD)、扫描电镜(SEM)和振动样品磁强计(VSM)对其形状、尺寸、荧光及磁特性进行了表征,探讨了其在细胞分离和细胞芯片上的应用和原理. 相似文献
17.
合成了Co@SiO2核壳式纳米粒子, 并采用透射电镜(TEM)、 X射线衍射(XRD)、扫描电镜(SEM)和振动样品磁强计(VSM)对其形状、尺寸、荧光及磁特性进行了表征, 探讨了其在细胞分离和细胞芯片上的应用和原理. 相似文献
18.
19.
Penglong Tan Chunyang LeiXin Liu Meng QingZhou Nie Manli GuoYan Huang Shouzhuo Yao 《Analytica chimica acta》2013
We report here an affinity separation-based fluorometric method for monitoring the activity and inhibition of protein kinase. In this assay, when the fluorescein isothiocyanate (FITC) labeled substrate peptides (S-peptide) are phosphorylated by kinase, the product peptides (P-peptide) will be adsorbed and concentrated onto the surface of Zr4+-immobilized nitrilotriacetic acid-coated magnetic nanoparticles (Zr-NTA MNPs) through the chelation of Zr4+ and phosphate groups. After magnetic separation, the fluorescence intensity of the homogeneous solution changes dramatically. Hence the fluorescence response allows this MNPs-based method to easily probe kinase activity by a spectrometer. The feasibility of the method has been demonstrated by sensitive measurement of the activity of cAMP-dependent protein kinase (PKA) with a low detection limit (0.5 mU μL−1). Moreover, the system is successfully applied to estimate the IC50 value of PKA inhibitor H-89 and detect the Forskolin/3-isobutyl-1-methylxanthine (IBMX) stimulated activation of PKA in cell lysate. Additionally, Zr-NTA MNPs are reusable by stripping Zr4+ ions from NTA-coated MNPs and rechelating again. This method, which relies on the surface-functionalized MNPs, presents a promising candidate for simple and cost-effective assay of kinase activity and inhibitor screening. 相似文献
20.
Wenjun Li Yaping Zhang Yanchao Wang Yue Ma Dongyuan Wang Heng Li Xiyang Ye Feng Yin Zigang Li 《中国化学快报》2021,32(4):1571-1574
Herein, we utilized nucleic acids induced peptide co-assembly strategy to develop novel nucleic acids induced peptide-based AIE (NIP-AIE) nanoparticles. Strong fluorescent of AIE could be observed when a little amount of nucleic acids was added into the peptide solution, and the intensity could be regulated by the concentration of nucleic acids. This AIE nanoparticle with good biocompatibility could achieve fast cell imaging. It is also proved that the fluorescence intensity of AIE decreased with time, which indicates that the reducible cross-linkers of Wpc peptide by GSH and nanoparticles gradually disintegrate in cell. Based on the different of AIE fluorescence signals which regulated by the formation and disintegration of nanoparticles, this AIE system is expected to be used for real-time monitoring of drug release from peptide-based nano carriers in vivo or in vitro, and may provide a new platform for the construction of other organic AIE nanoparticles. 相似文献