We report a dynamic covalent approach to transmembrane transport of amino acids by the formation of a three-component assembly. A mixture of a squaramide and a lipophilic and electrophilic aldehyde is shown to synergistically transport highly polar glycine (Gly) across vesicle membranes. The transport was investigated by a (13)C NMR assay, an osmotic response assay, a newly developed fluorescence assay suitable for measuring Gly influx, and other fluorescence assays for leakage and pH change. The transport is proposed to occur via a hydrogen-bonded anionic glycine hemiaminal/imine, accompanied by transport of OH(-) in the opposite direction. Several control experiments support the role of hemiaminal/imine in the observed facilitated Gly transport. Proton NMR studies of a biphasic system show the presence of both the hemiaminal and imine formed between Gly and an aldehyde. Interestingly, the synergistic effect has also been observed for sarcosine, which can form hemiaminals but not imines. The results demonstrate the potential of hemiaminal formation for the facilitated transport of substrates containing primary and secondary amino groups.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1021/ja510063n | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Kinetic Control of Self-Assembly Pathway in Dual Dynamic Covalent Polymeric Systems.
Angew Chem Int Ed Engl
January 2025
East China University of Science and Technology, School of Chemistry and Molecular Engineering, Meilong Road 130, 200237, Shanghai, CHINA.
Kinetically controlled self-assembly is garnering increasing interest in the field of supramolecular polymers and materials, yet examples involving dynamic covalent exchange remain relatively unexplored. Here we report an unexpected dynamic covalent polymeric system whose aqueous self-assembly pathway is strongly influenced by the kinetics of evaporation of water. The key design is to integrate dual dynamic covalent bonds-including disulfide bonds and boroxine/borate-into a dynamic equilibrium system of monomers, polymers, and materials.
View Article and Find Full Text PDFFluorescent Artificial Receptor for Dopamine based on Molecular Recognition-driven Dynamic Covalent Chemistry in a Lipid Nanoreactor.
Angew Chem Int Ed Engl
January 2025
University of Strasbourg, UMR 7213 CNRS, 74, Route du Rhin, 67401, Illkirch-Strasbourg, FRANCE.
Molecular recognition and detection of small bioactive molecules, like neurotransmitters, remain a challenge for chemists, whereas nature found an elegant solution in form of protein receptors. Here, we introduce a concept of a dynamic artificial receptor that synergically combines molecular recognition with dynamic imine bond formation inside a lipid nanoreactor, inducing a fluorescence response. The designed supramolecular system combines a lipophilic recognition ligand derived from a boronic acid, a fluorescent aldehyde based on push-pull styryl pyridine and a phenol-based catalyst.
View Article and Find Full Text PDFRegulation of stress granule maturation and dynamics by poly(ADP-ribose) interaction with PARP13.
Nat Commun
January 2025
Department of Biochemistry and Molecular Biology, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD, USA.
Non-covalent interactions of poly(ADP-ribose) (PAR) facilitate condensate formation, yet the impact of these interactions on condensate properties remains unclear. Here, we demonstrate that PAR-mediated interactions through PARP13, specifically the PARP13.2 isoform, are essential for modulating the dynamics of stress granules-a class of cytoplasmic condensates that form upon stress, including types frequently observed in cancers.
View Article and Find Full Text PDFA Schiff base-functionalized chitosan magnetic bio-nanocomposite for efficient removal of Pb (II) and Cd (II) ions from aqueous solutions.
Int J Biol Macromol
January 2025
Department of Chemistry, Faculty of Science, Arak University, Arak 38481-77584, Iran; Institute of Nanosciences &Nanotechnology, Arak University, Arak, Iran. Electronic address:
The rapid industrialization and human activities in catchments have posed notable global challenges in removing of heavy metal contaminants from wastewater. Here, Schiff-bases (SB) of cyanoguanidine (CG) and salicylaldehyde (SA) were covalently grafted on a magnetic nanocomposite of chitosan to form a hybrid magnetic nanostructure (FeO@CS-CGSB). The synthesized structure was characterized using various techniques such as Fourier transform infrared spectroscopy (FT-IR), field emission scanning electron microscopy (SEM), transmission electron microscopy (TEM), powder X-ray diffraction (XRD), thermogravimetric analysis (TGA), vibrating sample magnetometry (VSM), dynamic light scattering (DLS), zeta potential, and Brunauer-Emmett-Teller surface area analysis (BET).
View Article and Find Full Text PDFStructural Dynamics of the Ubiquitin Specific Protease USP30 in Complex with a Cyanopyrrolidine-Containing Covalent Inhibitor.
J Proteome Res
January 2025
Target Discovery Institute, Centre for Medicines Discovery, Nuffield Department of Medicine, University of Oxford, Oxford, OX3 7FZ, U.K.
Inhibition of the mitochondrial deubiquitinating (DUB) enzyme USP30 is neuroprotective and presents therapeutic opportunities for the treatment of idiopathic Parkinson's disease and mitophagy-related disorders. We integrated structural and quantitative proteomics with biochemical assays to decipher the mode of action of covalent USP30 inhibition by a small-molecule containing a cyanopyrrolidine reactive group, . The inhibitor demonstrated high potency and selectivity for endogenous USP30 in neuroblastoma cells.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!