Highly Sequence-Dependent Formation of Fluorescent Silver Nanoclusters in Hybridized DNA Duplexes for Single Nucleotide Mutation Identification

Highly Sequence-Dependent Formation of Fluorescent Silver Nanoclusters in Hybridized DNA Duplexes for Single Nucleotide Mutation Identificatio

Versatile CRISPR-Cas12a-Based Biosensing Platform Modulated with Programmable Entropy-Driven Dynamic DNA Networks

In addition to their roles as revolutionary genome engineering tools, CRISPR-Cas systems are also highly promising candidates in the construction of biosensing systems and diagnostic devices, which have attracted significant attention recently. However, the CRISPR-Cas system cannot be directly applied in the sensing of non-nucleic acid targets, and the needs of synthesizing and storing different vulnerable guide RNA for different targets also increase the application and storage costs of relevant biosensing systems, and therefore restrict their widespread applications. To tackle these barriers, in this work, a versatile CRISPR-Cas12a-based biosensing platform was developed through the introduction of an enzyme-free and robust DNA reaction network, the entropy-driven dynamic DNA network. By programming the sequences of the system, the entropy-driven catalysis-based dynamic DNA network can respond to different types of targets, such as nucleic acids or proteins, and then activate the CRISPR-Cas12a to generate amplified signals. As a proof of concept, both nucleic acid targets (a DNA target with random sequence, T, and an RNA target, microRNA-21 (miR-21)) and a non-nucleic acid target (a protein target, thrombin) were chosen as model analytes to address the feasibility of the designed sensing platform, with detection limits at the pM level for the nucleic acid analytes (7.4 pM for the DNA target T and 25.5 pM for miR-21) and 0.4 nM for thrombin. In addition, the detection of miR-21 or thrombin in human serum samples further demonstrated the applicability of the proposed biosensing platform in real sample analysis

Aerobic Oxidation of Formaldehyde Catalyzed by Polyvanadotungstates

Three tetra-<i>n</i>-butylammonium (TBA) salts of polyvanadotungstates, [<i>n</i>-Bu₄N]₆[PW₉V₃O₄₀] (<b>PW</b>_<b>9</b><b>V</b>_<b>3</b>), [<i>n</i>-Bu₄N]₅H₂PW₈V₄O₄₀ (<b>PW</b>_<b>8</b><b>V</b>_<b>4</b>), and [<i>n</i>-Bu₄N]₄H₅PW₆V₆O₄₀·20H₂O (<b>PW</b>_<b>6</b><b>V</b>_<b>6</b>), have been synthesized and shown to be effective catalysts for the aerobic oxidation of formaldehyde to formic acid under ambient conditions. These complexes, characterized by elemental analysis, Fourier transform infrared spectroscopy, UV–vis spectroscopy, and thermogravimetric analysis, exhibit a catalytic activity for this reaction comparable to those of other polyoxometalates. Importantly, they are more effective in the presence of water than the metal oxide-supported Pt and/or Au nanoparticles traditionally used as catalysts for formaldehyde oxidation in the gas phase. The polyvanadotungstate-catalyzed oxidation reactions are first-order in formaldehyde, parabolic-order (slow, fast, and slow again) in catalyst, and zero-order in O₂. Under optimized conditions, a turnover number of ∼57 has been obtained. These catalysts can be recycled and reused without a significant loss of catalytic activity

Additional file 5 of Large-scale analysis of protein crotonylation reveals its diverse functions in Pinellia ternata

Additional file 5: Supplementary Table S4. KEGG pathway analysis of crotonylated proteins in the leaves of P. ternata

Additional file 7 of Large-scale analysis of protein crotonylation reveals its diverse functions in Pinellia ternata

Additional file 7: Supplementary Table S6. Annotation of the total proteins in the leaves of P. ternata

Additional file 1 of Large-scale analysis of protein crotonylation reveals its diverse functions in Pinellia ternata

Additional file 1: Fig. S1. The flow chart of lysine crotonylation analysis (a), Distribution of Kcr-modified proteins based on the number of crotonylation sites in a protein (b). The analysis was performed based on 2106 crotonylated sites matched on 1006 proteins overlapping in three independent tests

Additional file 6 of Large-scale analysis of protein crotonylation reveals its diverse functions in Pinellia ternata

Additional file 6: Supplementary Table S5. Protein domain enrichment analysis of crotonylated proteins in the leaves of P. ternata

Chiral π–Cu(II) Catalysts for the Enantioselective α‑Amination of <i>N</i>‑Acyl-3,5-dimethylpyrazoles

We report the highly enantioselective α-amination of N-acyl-3,5-dimethylpyrazoles with dialkyl azodicarboxylates, catalyzed by in situ generated π–Cu(II) complexes that consist of Cu(OTf)2 and N-(5H-dibenzo[a,d][7]annulen-5-yl)-l-alanine-derived amides, to give the corresponding products as d-α-amino acid derivatives (up to >99% yield and 99% ee). The site-selectivity and enantioselectivity can be satisfactorily explained by the coordination of dialkyl azodicarboxylate with π–Cu(II) complex. The synthetic potential of this one-pot transformation to the α-amino ester is also described

Additional file 2 of Large-scale analysis of protein crotonylation reveals its diverse functions in Pinellia ternata

Additional file 2: Supplementary Table S1. Crotonylated sites of proteins in the leaves of P. ternata