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991.
Synthesis of orientedly bioconjugated core/shell Fe3O4@Au magnetic nanoparticles for cell separation
Orientedly bioconjugated core/shell Fe3O4@Au magnetic nanoparticles were synthesized for cell separation. The Fe3O4@Au magnetic nanoparticles were synthesized by reducing HAuCl4 on the surfaces of Fe3O4 nanoparticles, which were further characterized in detail by TEM, XRD and UV-vis spectra. Anti-CD3 monoclonal antibody was orientedly bioconjugated to the surface of Fe3O4@Au nanoparticles through affinity binding between the Fc portion of the antibody and protein A that covalently immobilized on the nanoparticles. The oriented immobilization method was performed to compare its efficiency for cell separation with the non-oriented one, in which the antibody was directly immobilized onto the carboxylated nanoparticle surface. Results showed that the orientedly bioconjugated Fe3O4@Au MNPs successfully pulled down CD3+ T cells from the whole splenocytes with high efficiency of up to 98.4%, showing a more effective cell-capture nanostructure than that obtained by non-oriented strategy. This developed strategy for the synthesis and oriented bioconjugation of Fe3O4@Au MNPs provides an efficient tool for cell separation, and may be further applied to various fields of bioanalytical chemistry for diagnosis, affinity extraction and biosensor. 相似文献
992.
Alexander J. Pérez Frank Wesche Dr. Hélène Adihou Prof. Dr. Helge B. Bode 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(2):639-645
Many methods have been devised over the decades to trace precursors of specific molecules in cellular environments as, for example, in biosynthesis studies. The advent of click chemistry has facilitated the powerful combination of tracing and at the same time sieving the highly complex metabolome for compounds derived from simple or complex starting materials, especially when the click reaction takes place on a solid support. While the principle of solid‐phase click reactions has already been successfully applied for selective protein and peptide enrichment, the successful enrichment of much smaller primary and secondary metabolites, showing great structural diversity and undergoing many different biosynthetic steps, has seen only little development. For bacterial secondary metabolism, a far broader tolerance for “clickable” precursors was observed than in ribosomal proteinogenesis, thus making this method a surprisingly valuable tool for the tracking and discovery of compounds within the cellular biochemical network. The implementation of this method has led to the identification of several new compounds from the bacterial genera Photorhabdus and Xenorhabdus, clearly proving its power. 相似文献
993.
Eirini Antonatou Dr. Kurt Hoogewijs Dr. Dimitris Kalaitzakis Andreas Baudot Prof. Georgios Vassilikogiannakis Prof. Annemieke Madder 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(25):8457-8461
A novel chemoselective ligation methodology has been developed for the facile construction of peptide‐based fluorescent probes. Furan‐containing peptides were activated by singlet oxygen and covalently engaged by nitrogen nucleophiles to yield stable conjugates. Singlet oxygen was compatible with sensitive amino acid residues within the peptides and a range of fluorophores, bearing different functionalities, were successfully incorporated, illustrating the broad scope of the developed strategy. 相似文献
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995.
Jochen Stehle Robert Silvers Karla Werner Deep Chatterjee Santosh Gande Frank Scholz Arpana Dutta Josef Wachtveitl Judith Klein‐Seetharaman Harald Schwalbe 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2014,126(8):2110-2116
The mammalian visual dim‐light photoreceptor rhodopsin is considered a prototype G protein‐coupled receptor. Here, we characterize the kinetics of its light‐activation process. Milligram quantities of α,ε‐15N‐labeled tryptophan rhodopsin were produced in stably transfected HEK293 cells. Assignment of the chemical shifts of the indole signals was achieved by generating the single‐point‐tryptophan to phenylalanine mutants, and the kinetics of each of the five tryptophan residues were recorded. We find kinetic partitioning in rhodopsin decay, including three half‐lives, that reveal two parallel processes subsequent to rhodopsin activation that are related to the photocycle. The meta II and meta III states emerge in parallel with a relative ratio of about 3:1. Transient formation of the meta III state was confirmed by flash photolysis experiments. From analysis of the site‐resolved kinetic data we propose the involvement of the E2‐loop in the formation of the meta III state. 相似文献
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Yihui Shen Fang Xu Lu Wei Fanghao Hu Prof. Wei Min 《Angewandte Chemie (International ed. in English)》2014,53(22):5596-5599
Protein degradation is a regulatory process essential to cell viability and its dysfunction is implicated in many diseases, such as aging and neurodegeneration. In this report, stimulated Raman scattering microscopy coupled with metabolic labeling with 13C‐phenylalanine is used to visualize protein degradation in living cells with subcellular resolution. We choose the ring breathing modes of endogenous 12C‐phenylalanine and incorporated 13C‐phenylalanine as protein markers for the original and nascent proteomes, respectively, and the decay of the former wasquantified through 12C/(12C+13C) ratio maps. We demonstrate time‐dependent imaging of proteomic degradation in mammalian cells under steady‐state conditions and various perturbations, including oxidative stress, cell differentiation, and huntingtin protein aggregation. 相似文献
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