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Wojtek Steffen, Fu Chong Ko, Jigar Patel, Victor Lyamichev, Tom Albert, Jörg Benz, Markus G Rudolph, Frank Bergmann, Thomas Streidl, Peter Kratzsch, Mara Boenitz-Dulat, Tobias Oelschlaegel, Michael Schraeml
Microbial transglutaminases (MTGs) catalyze the formation of Gln-Lys isopeptide bonds and are widely used for the crosslinking of proteins and peptides in food and biotechnological applications, for example, to improve the texture of protein-rich foods or in generating antibody-drug conjugates. Currently used MTGs have low substrate specificity, impeding their biotechnological use as enzymes that don't cross-react with nontarget substrates (i.e. as bio-orthogonal labeling systems). Here, we report the discovery of a MTG from Kutzneria albida (KalbTG) which exhibited no cross-reactivity with known MTG substrates or commonly used target proteins such as antibodies...
July 27, 2017: Journal of Biological Chemistry
Hyeon Jeong Lee, Ji-Xin Cheng
Stimulated Raman scattering (SRS) microscopy is a vibrational imaging platform developed to visualize chemical content of a biological sample based on molecular vibrational fingerprints. With high-speed, high-sensitivity, and three-dimensional sectioning capability, SRS microscopy has been used to study chemical distribution, molecular transport, and metabolic conversion in living cells in a label-free manner. Moreover, aided with bio-orthogonal small-volume Raman probes, SRS microscopy allows direct imaging of metabolic activities of small molecules in living cells...
September 1, 2017: Methods: a Companion to Methods in Enzymology
Akifumi Kato, Mitsuo Kuratani, Tatsuo Yanagisawa, Kazumasa Ohtake, Akiko Hayashi, Yoshimi Amano, Kaname Kimura, Shigeyuki Yokoyama, Kensaku Sakamoto, Yasuhisa Shiraishi
The site-specific chemical conjugation of proteins, following synthesis with an expanded genetic code, promises to advance antibody-based technologies, including antibody drug conjugation and the creation of bispecific Fab dimers. The incorporation of non-natural amino acids into antibodies not only guarantees site specificity but also allows the use of bio-orthogonal chemistry. However, the efficiency of amino acid incorporation fluctuates significantly among different sites, thereby hampering the identification of useful conjugation sites...
August 16, 2017: Bioconjugate Chemistry
Lin Wang, Rui Jiang, Yang Liu, Maosheng Cheng, Qingyu Wu, Xue-Long Sun
Thrombomodulin (TM) is an endothelial cell membrane protein that acts as a major cofactor in the protein C anticoagulant pathway. The EGF-like domains 4-6 of TM (TM456) are essential for PC activation. In this study, we proposed a liposomal recombinant TM conjugate to mimic the membrane TM structure and its anticoagulant activity. First, a DSPE-PEG2000-TM456 was successfully synthesized by site-specific conjugation of azido-TM456 with DSPE-PEG2000-DBCO via copper-free click chemistry quantitatively. Then, liposome-TM456 was fabricated via direct liposome formation with the DSPE-PEG2000-TM456 and other lipids...
October 2017: Journal of Bioscience and Bioengineering
Ji Hee Kang, Kyoung-Ran Kim, Hyukjin Lee, Dae-Ro Ahn, Young Tag Ko
Deoxyribonucleic acid (DNA) is a versatile material with high applicability and inherent biocompatibility. L-DNA, the perfect mirror form of the naturally occurring D-DNA, has been used in DNA nanotechnology. It has thermodynamically identical properties to D-DNA, is capable of self-assembly and bio-orthogonal base-pairing, and is resistant to nuclease activity. We previously constructed an L-DNA tetrahedron (L-Td) and found that this nanostructure has remarkably higher capacity for cell penetration than its natural counterpart (D-Td)...
September 1, 2017: Colloids and Surfaces. B, Biointerfaces
Hyun Jong Lee, Gabriella M Fernandes-Cunha, Ilham Putra, Won-Gun Koh, David Myung
Surface modifications with tethered growth factors have mainly been applied to synthetic polymeric biomaterials in well-controlled, acellular settings, followed by seeding with cells. The known bio-orthogonality of copper-free click chemistry provides an opportunity to not only use it in vitro to create scaffolds or pro-migratory tracks in the presence of living cells, but also potentially apply it to living tissues directly as a coupling modality in situ. In this study, we studied the chemical coupling of growth factors to collagen using biocompatible copper-free click chemistry and its effect on the enhancement of growth factor activity in vitro...
July 19, 2017: ACS Applied Materials & Interfaces
Paul J O'Brien, Sina Elahipanah, Dmitry Rogozhnikov, Muhammad N Yousaf
The efficient delivery of foreign nucleic acids (transfection) into cells is a critical tool for fundamental biomedical research and a pillar of several biotechnology industries. There are currently three main strategies for transfection including reagent, instrument, and viral based methods. Each technology has significantly advanced cell transfection; however, reagent based methods have captured the majority of the transfection market due to their relatively low cost and ease of use. This general method relies on the efficient packaging of a reagent with nucleic acids to form a stable complex that is subsequently associated and delivered to cells via nonspecific electrostatic targeting...
May 24, 2017: ACS Central Science
Sylvain Ursuegui, Marion Recher, Wojciech Krężel, Alain Wagner
Drugs, usually long acting and metabolically stable molecules, might be the source of adverse effects triggered by complex drug interactions, anaphylaxis and drug-induced coagulopathy. To circumvent this growing drug safety issue, we herein investigate the opportunity offered by bio-orthogonal chemistry for in vivo drug neutralization. We design a small-molecule anticoagulant drug (Warfarin) containing an azide group that acts as a safety pin. It allows drug deactivation and restoration of physiological coagulation via in vivo click reaction with a suitable cyclooctyne-based neutralizing agent...
May 19, 2017: Nature Communications
Ruben T Almaraz, Yanhong Li
Structural glycobiology has traditionally been a challenging field due to a limited set of tools available to investigate the diverse and complex glycan molecules. However, we cannot ignore that glycans play critical roles in health as well as in disease, and are present in more than 50% of all proteins and on over 80% of all surface proteins. Chemoenzymatic glycoengineering (CGE) methods are a powerful set of tools to synthesize complex glycans, but the full potential of these methods have not been explored in cell biology yet...
June 15, 2017: Biology Open
Yasuyuki Yoshida, Kazuyuki Takata, Hiroki Takai, Keisuke Kawahara, Akinori Kuzuya, Yuichi Ohya
On clinical application of biodegradable injectable polymer (IP) systems, quick extemporaneous preparation of IP formulations and longer duration time gel state after injection into the body are the important targets to be developed. Previously, we had reported temperature-responsive covalent gelation systems via bio-orthogonal thiol-ene reaction by 'mixing strategy' of amphiphilic biodegradable tri-block copolymer (tri-PCG) attaching acryloyl groups on both termini (tri-PCG-Acryl) with reactive polythiol. In other previous works, we found 'freeze-dry with PEG/dispersion' method as quick extemporaneous preparation method of biodegradable IP formulations...
May 23, 2017: Journal of Biomaterials Science. Polymer Edition
Fatimata Dembele, Mariana Tasso, Laura Trapiella-Alfonso, Xiangzhen Xu, Mohamed Hanafi, Nicolas Lequeux, Thomas Pons
Fluorescent semiconductor quantum dots (QDs) exhibit several unique properties that make them suitable candidates for biomolecular sensing, including high brightness, photostability, broad excitation, and narrow emission spectra. Assembling these QDs into robust and functionalizable nanosized clusters (QD-NSCs) can provide fluorescent probes that are several orders of magnitude brighter than individual QDs, thus allowing an even greater sensitivity of detection with simplified instrumentation. However, the formation of compact, antifouling, functionalizable, and stable QD-NSCs remains a challenging task, especially for a use at ultralow concentrations for single-molecule detection...
May 17, 2017: ACS Applied Materials & Interfaces
Amin Famili, Karthikan Rajagopal
Chemically cross-linked hydrogels are promising systems for protein delivery applications, but their utility may be limited due to the possibility of protein reaction with hydrogel precursors. Herein, a catalyst-free inverse-demand Diels-Alder reaction between tetrazine and norbornene groups was used to demonstrate the bio-orthogonal nature of cross-linking chemistry that is chemically inert to proteins. Tetrazine-modified hyaluronic acid and norbornene-modified polyethylene glycol were used as hydrogel precursors for in situ encapsulation of a model protein, Fab1...
May 16, 2017: Molecular Pharmaceutics
Volkan Sakin, Janina Hanne, Jessica Dunder, Maria Anders-Össwein, Vibor Laketa, Ivana Nikić, Hans-Georg Kräusslich, Edward A Lemke, Barbara Müller
The envelope glycoproteins (Env) of HIV-1 mediate cell entry through fusion of the viral envelope with a target cell membrane. Intramembrane mobility and clustering of Env trimers at the viral budding site are essential for its function. Previous live-cell and super-resolution microscopy studies were limited by lack of a functional fluorescent Env derivative, requiring antibody labeling for detection. Introduction of a bio-orthogonal amino acid by genetic code expansion, combined with click chemistry, offers novel possibilities for site-specific, minimally invasive labeling...
May 18, 2017: Cell Chemical Biology
Jerzy Kozyra, Alessandro Ceccarelli, Emanuela Torelli, Annunziata Lopiccolo, Jing-Ying Gu, Harold Fellermann, Ulrich Stimming, Natalio Krasnogor
Nanotechnology and synthetic biology are rapidly converging, with DNA origami being one of the leading bridging technologies. DNA origami was shown to work well in a wide array of biotic environments. However, the large majority of extant DNA origami scaffolds utilize bacteriophages or plasmid sequences thus severely limiting its future applicability as a bio-orthogonal nanotechnology platform. In this paper we present the design of biologically inert (i.e., "bio-orthogonal") origami scaffolds. The synthetic scaffolds have the additional advantage of being uniquely addressable (unlike biologically derived ones) and hence are better optimized for high-yield folding...
July 21, 2017: ACS Synthetic Biology
Yu Zhao, Sarah G Bolton, Michael D Pluth
Hydrogen sulfide (H2S) is an important biomolecule, and responsive chemical tools for its delivery are needed. Here, we utilize the photocleavable o-nitrobenzyl group to unmask caged thiocarbamates and to access photoactivated H2S releasing molecules. These donors function by the initial release of carbonyl sulfide (COS), which is quickly hydrolyzed to H2S by carbonic anhydrase (CA). Our investigations demonstrate that o-nitrobenzyl-caged thiocarbamates can serve as a donor platform for the bio-orthogonal stimulated release of COS/H2S...
May 5, 2017: Organic Letters
Chen Guo, Heejae Kim, Elisa M Ovadia, Christine M Mourafetis, Mingrui Yang, Wilfred Chen, April M Kloxin
Hydrogels are facile architectures for the controlled presentation of proteins with far-reaching applications, from fundamental biological studies in three-dimensional culture to new regenerative medicine and therapeutic delivery strategies. Here, we demonstrate a versatile approach for spatially-defined presentation of engineered proteins within hydrogels through i) immobilization using bio-orthogonal strain-promoted alkyne-azide click chemistry and ii) dynamic protease-driven protein release using exogenously applied enzyme...
July 1, 2017: Acta Biomaterialia
Eszter Kozma, Orsolya Demeter, Péter Kele
No abstract text is available yet for this article.
March 16, 2017: Chembiochem: a European Journal of Chemical Biology
Wenqi Liu, Soumen K Samanta, Bradley D Smith, Lyle Isaacs
Biotin/(strept)avidin self-assembly is a powerful platform for nanoscale fabrication and capture with many different applications in science, medicine, and nanotechnology. However, biotin/(strept)avidin self-assembly has several well-recognized drawbacks that limit performance in certain technical areas and there is a need for synthetic mimics that can either become superior replacements or operational partners with bio-orthogonal recognition properties. The goal of this tutorial review is to describe the recent progress in making high affinity synthetic association partners that operate in water or biological media...
May 9, 2017: Chemical Society Reviews
Christopher M Madl, Sarah C Heilshorn
Engineered protein hydrogels have shown promise as artificial extracellular matrix materials for the 3D culture of stem cells due to the ability to decouple hydrogel biochemistry and mechanics. The modular design of these proteins allows for incorporation of various bioactive sequences to regulate cellular behavior. However, the chemistry used to cross-link the proteins into hydrogels can limit what bioactive sequences can be incorporated, in order to prevent nonspecific cross-linking within the bioactive region...
March 15, 2017: Bioconjugate Chemistry
Alessandro Ranalli, Melissa Santi, Luigi Capriotti, Valerio Voliani, David Porciani, Fabio Beltram, Giovanni Signore
Stealth agents are extensively investigated as a means by which to prolong nanostructure residence time in the bloodstream by avoiding uptake by the reticuloendothelial system. Unfortunately, commonly used agents such as poly(ethylene glycol) can adversely impact targeting efficiency and promote immune reaction by the host organism. Therefore, there is an increasing interest in developing biocompatible, non-PEGylated organic nanostructures able to perform targeted delivery to increase the efficacy of liposomal technology...
February 15, 2017: Bioconjugate Chemistry
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