The products of multi-step automated solid phase syntheses are purified after release from the resin. Capping of unreacted nucleophiles is commonplace in automated oligonucleotide synthesis to minimize accumulation of deletion sequences. To date, capping was not used routinely during automated glycan assembly (AGA) since previous capping protocols suffered from long reaction times and conditions incompatible with some protective groups. Here, a method using methanesulfonic acid and acetic anhydride for the fast and quantitative capping of hydroxyl groups that failed to be glycosylated is reported. Commonly used protective groups in AGA are stable under these capping conditions. The introduction of a capping step into the coupling cycle drastically improved overall yields by decreasing side-products and simplifying purification, while reducing building block consumption. To illustrate the method, the biologically important tetrasaccharide Lc4, as well as a 50-mer polymannoside were prepared.
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http://dx.doi.org/10.1002/chem.201801023 | DOI Listing |
Mol Biol Cell
January 2025
Dept. of Biochemistry & Molecular Biology, University of Nebraska Medical Center, Omaha, NE, 68198.
The primary cilium is a crucial signaling organelle that can be generated by most human cells, and impediments to primary ciliogenesis lead to a variety of developmental disorders known as ciliopathies. The removal of the capping protein, CP110, from the mother centriole is a crucial early step that promotes generation of the ciliary vesicle and ciliogenesis. Recent studies have demonstrated that CP110 undergoes polyubiquitination and degradation in the proteosome, but the mechanisms of unfolding and removal from the mother centriole remain unknown.
View Article and Find Full Text PDFLangmuir
January 2025
Department of Chemistry, University of Washington, Seattle, Washington 98195, United States.
Circular dichroism (CD) spectroscopy has emerged as a potent tool for probing chiral small-molecule ligand exchange on natively achiral quantum dots (QDs). In this study, we report a novel approach to identifying QD-biomolecule interactions by inducing chirality in CdS QDs using thermoresponsive elastin-like polypeptides (ELPs) engineered with C-terminal cysteine residues. Our method is based on a versatile two-step ligand exchange process starting from monodisperse oleate-capped QDs in nonpolar media and proceeding through an easily accessed achiral glycine-capped QD intermediate.
View Article and Find Full Text PDFInt J Biol Macromol
December 2024
Department of Chemistry, University of Ulsan, Ulsan 44610, Republic of Korea. Electronic address:
The improper handling and uncontrolled discharge of toxic organic dyes result in significant adverse effects on both human health and the environment. This study investigates the fabrication of SnO₂, yttrium and cobalt dual-doped SnO₂ (YCSn), chitosan-capped SnO₂ (CS*Sn), and chitosan-capped yttrium and cobalt dual-doped SnO₂ (CS*YCSn) nanoparticles using a one-step coprecipitation method for the photocatalytic degradation of methylene blue (MB) under visible light irradiation. Characterization techniques including X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), high-resolution transmission electron microscopy (HRTEM), and ultraviolet-visible (UV-Vis) spectrophotometry confirm the successful synthesis of biodegradable CS*YCSn nanoparticles.
View Article and Find Full Text PDFChem Sci
December 2024
Frontier Institute of Science and Technology, State Key Laboratory of Electrical Insulation and Power Equipment, MOE Key Laboratory for Nonequilibrium Synthesis of Condensed Matter, Xi'an Key Laboratory of Electronic Devices and Materials Chemistry and School of Chemistry, Xi'an Jiaotong University 99 Yanxiang Road Xi'an Shaanxi 710054 P. R. China
The benzene tetraanion-bridged rare earth inverse arene amidinate complexes [{Ln(κ:η-Piso)}(μ-η:η-CH)] (2-Ln, Ln = Gd, Tb, Dy, Y; Piso = {(NDipp)C Bu}, Dipp = CH Pr-2,6) were prepared by the reduction of parent Ln(iii) bis-amidinate halide precursors [Ln(Piso)X] (Ln = Tb, Dy; X = Cl, I) or [Ln(Piso)I] (Ln = Gd, Y) with 3 eq. KC in benzene, or by the reaction of the homoleptic Ln(ii) complexes [Ln(Piso)] (Ln = Tb, Dy) with 2 eq. KC in benzene.
View Article and Find Full Text PDFACS Meas Sci Au
December 2024
Synthetic Molecule Analytical Chemistry, Genentech, 1 DNA Way, South San Francisco, California 94080, United States.
Small molecules and antibodies have dominated the pharmaceutical landscape for decades. However, limitations associated with therapeutic targets deemed "undruggable" and progress in biology and chemistry have led to the blossoming of drug modalities and therapeutic approaches. In 2023, a high number of 9 oligonucleotide and peptide products were approved by the Food and Drug Administration (FDA), accounting for 16% of all drugs approved.
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