共查询到20条相似文献，搜索用时 15 毫秒
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Schäffer C Novotny R Küpcü S Zayni S Scheberl A Friedmann J Sleytr UB Messner P 《Small (Weinheim an der Bergstrasse, Germany)》2007,3(9):1549-1559
The crystalline cell-surface (S) layer sgsE of Geobacillus stearothermophilus NRS 2004/3a represents a natural protein self-assembly system with nanometer-scale periodicity that is evaluated as a combined carrier/patterning element for the conception of novel types of biocatalyst aiming at the controllable display of biocatalytic epitopes, storage stability, and reuse. The glucose-1-phosphate thymidylyltransferase RmlA is used as a model enzyme and chimeric proteins are constructed by translational fusion of rmlA to the C-terminus of truncated forms of sgsE (rSgsE (131-903), rSgsE(331-903)) and used for the construction of three principal types of biocatalysts: soluble (monomeric), self-assembled in aqueous solution, and recrystallized on negatively charged liposomes. Enzyme activity of the biocatalysts reaches up to 100 % compared to sole RmlA cloned from the same bacterium. The S-layer portion of the biocatalysts confers significantly improved shelf life to the fused enzyme without loss of activity over more than three months, and also enables biocatalyst recycling. These nanopatterned composites may open up new functional concepts for biocatalytic applications in nanobiotechnology. 相似文献
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Aitziber Eleta Lopez Susana Moreno‐Flores Dietmar Pum Uwe B. Sleytr José L. Toca‐Herrera 《Small (Weinheim an der Bergstrasse, Germany)》2010,6(3):396-403
The self‐assembly kinetics and nanocrystal formation of the bacterial surface‐layer‐protein SbpA are studied with a combination of quartz crystal microbalance with dissipation monitoring (QCM‐D) and atomic force microscopy (AFM). Silane coupling agents, aminopropyltriethoxysilane (APTS) and octadecyltrichlorosilane (OTS), are used to vary the protein–surface interaction in order to induce new recrystallization pathways. The results show that the final S‐layer crystal lattice parameters (a = b = 14 nm, γ = 90°), the layer thickness (15 nm), and the adsorbed mass density (1700 ng cm?2) are independent of the surface chemistry. Nevertheless, the adsorption rate is five times faster on APTS and OTS than on SiO2, strongly affecting protein nucleation and growth. As a consequence, protein crystalline domains of 0.02 µm2 for APTS and 0.05 µm2 for OTS are formed, while for silicon dioxide the protein domains have a typical size of about 32 µm2. In addition, more‐rigid crystalline protein layers are formed on hydrophobic substrates. In situ AFM experiments reveal three different kinetic steps: adsorption, self‐assembly, and crystalline‐domain reorganization. These steps are corroborated by frequency–dissipation curves. Finally, it is shown that protein adsorption is a diffusion‐driven process. Experiments at different protein concentrations demonstrate that protein adsorption saturates at 0.05 mg mL?1 on silane‐coated substrates and at 0.07 mg mL?1 on hydrophilic silicon dioxide. 相似文献
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Eduardo Ruiz‐Hitzky Margarita Darder Pilar Aranda Katsuhiko Ariga 《Advanced materials (Deerfield Beach, Fla.)》2010,22(3):323-336
The rapid increase of interest in the field of biohybrid and biomimetic materials that exhibit improved structural and functional properties is attracting more and more researchers from life science, materials science, and nanoscience. Concomitant results offer valuable opportunities for applications that involve disciplines dealing with engineering, biotechnology, medicine and pharmacy, agriculture, nanotechnology, and others. In the current contribution we collect recent illustrative examples of assemblies between materials of biological origin and inorganic solids of different characteristics (texture, structure, and particle size). We introduce here a general overview on strategies for the preparation and conformation of biohybrids, the synergistic effects that determine the final properties of these materials, and their diverse applications, which cover areas as different as tissue engineering, drug delivery systems, biosensing devices, biocatalysis, green nanocomposites, etc. 相似文献
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By mimicking the stabilization of bacterial membranes with S-layer proteins, a novel process to fabricate highly stable protein microcapsules is introduced. In this strategy, engineered collagen peptides with site-specific biotinylation are assembled into microcapsules on the oil-in-water droplets, and the resulting microcapsules are reinforced by biomolecular-recognition-based cross-linking with the protein. Furthermore the microcapsules are shown to be versatile scaffolds for developing functionalized hierarchical colloidosomes for important biotechnological applications. 相似文献
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Christopher J. Hill Jennifer R. Fleming Masoumeh Mousavinejad Rachael Nicholson Svetomir B. Tzokov Per A. Bullough Julius Bogomolovas Mark R. Morgan Olga Mayans Patricia Murray 《Advanced materials (Deerfield Beach, Fla.)》2019,31(17)
The development of extracellular matrix mimetics that imitate niche stem cell microenvironments and support cell growth for technological applications is intensely pursued. Specifically, mimetics are sought that can enact control over the self‐renewal and directed differentiation of human pluripotent stem cells (hPSCs) for clinical use. Despite considerable progress in the field, a major impediment to the clinical translation of hPSCs is the difficulty and high cost of large‐scale cell production under xeno‐free culture conditions using current matrices. Here, a bioactive, recombinant, protein‐based polymer, termed ZTFn, is presented that closely mimics human plasma fibronectin and serves as an economical, xeno‐free, biodegradable, and functionally adaptable cell substrate. The ZTFn substrate supports with high performance the propagation and long‐term self‐renewal of human embryonic stem cells while preserving their pluripotency. The ZTFn polymer can, therefore, be proposed as an efficient and affordable replacement for fibronectin in clinical grade cell culturing. Further, it can be postulated that the ZT polymer has significant engineering potential for further orthogonal functionalization in complex cell applications. 相似文献
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Ziqi Sun Ting Liao Kesong Liu Lei Jiang Jung Ho Kim Shi Xue Dou 《Small (Weinheim an der Bergstrasse, Germany)》2014,10(15):3001-3006
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Tom Guterman Nicole L. Ing Sharon Fleischer Pavel Rehak Vasantha Basavalingappa Yamanappa Hunashal Ramachandra Dongre Srinivasarao Raghothama Petr Krl Tal Dvir Allon I. Hochbaum Ehud Gazit 《Advanced materials (Deerfield Beach, Fla.)》2019,31(10)
Bacterial type IV pili (T4P) are polymeric protein nanofibers that have diverse biological roles. Their unique physicochemical properties mark them as a candidate biomaterial for various applications, yet difficulties in producing native T4P hinder their utilization. Recent effort to mimic the T4P of the metal‐reducing Geobacter sulfurreducens bacterium led to the design of synthetic peptide building blocks, which self‐assemble into T4P‐like nanofibers. Here, it is reported that the T4P‐like peptide nanofibers efficiently bind metal oxide particles and reduce Au ions analogously to their native counterparts, and thus give rise to versatile and multifunctional peptide–metal nanocomposites. Focusing on the interaction with Au ions, a combination of experimental and computational methods provides mechanistic insight into the formation of an exceptionally dense Au nanoparticle (AuNP) decoration of the nanofibers. Characterization of the thus‐formed peptide–AuNPs nanocomposite reveals enhanced thermal stability, electrical conductivity from the single‐fiber level up, and substrate‐selective adhesion. Exploring its potential applications, it is demonstrated that the peptide–AuNPs nanocomposite can act as a reusable catalytic coating or form self‐supporting immersible films of desired shapes. The films scaffold the assembly of cardiac cells into synchronized patches, and present static charge detection capabilities at the macroscale. The study presents a novel T4P‐inspired biometallic material. 相似文献
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Goh Haw Zan Joshua A. Jackman Seong‐Oh Kim Nam‐Joon Cho 《Small (Weinheim an der Bergstrasse, Germany)》2014,10(23):4828-4832
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Amy&#x;Szuchmacher Blum Carissa&#x;M. Soto Charmaine&#x;D. Wilson Tina&#x;L. Brower Steven&#x;K. Pollack Terence&#x;L. Schull Anju Chatterji Tianwei Lin John&#x;E. Johnson Christian Amsinck Paul Franzon Ranganathan Shashidhar Banahalli&#x;R. Ratna 《Small (Weinheim an der Bergstrasse, Germany)》2005,1(7):669-669
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Minten IJ Wilke KD Hendriks LJ van Hest JC Nolte RJ Cornelissen JJ 《Small (Weinheim an der Bergstrasse, Germany)》2011,7(7):911-919
The cowpea chlorotic mottle virus (CCMV) is a versatile building block for the construction of nanoreactors and functional materials. Upon RNA removal, the capsid can be reversibly assembled and disassembed by adjusting the pH. At pH 5.0 the capsid is in the native assembled conformation, while at pH 7.5 it disassembles into 90 capsid protein dimers. This special property enables the encapsulation of various molecules, such as protein and enzymes, but only at low pH. It is possible to stabilize the capsid at pH 7.5 by addition of negatively charged polyelectrolytes or negatively charged particles, but these methods all fill the interior of the capsid, leaving little or no space for other cargo molecules. This pH restriction therefore severely limits the range of enzymes that can be encapsulated, and hampers the investigation of the CCMV capsid as a nanoreactor for the study of enzymes in confined spaces. Herein, the interaction of N-terminal histidine-tag-modified capsid proteins with several metal ions is reported. Depending on the conditions used, nanometer-sized protein particles or capsidlike architectures are formed that are stable at pH 7.5. This metal-mediated stabilization methodology is employed to form stable capsids containing multiple proteins at pH 7.5, thereby greatly expanding the scope of the CCMV capsid as a nanoreactor. 相似文献