Embedding Capture-Magneto-Catalytic Activity into a Nanocatalyst for the Determination of Lipid Kinase

Biosensors Based on the Binding Events of Nitrilotriacetic Acid-Metal Complexes

Molecular immobilization and recognition are two key events for the development of biosensors. The general ways for the immobilization and recognition of biomolecules include covalent coupling reactions and non-covalent interactions of antigen-antibody, aptamer-target, glycan-lectin, avidin-biotin and boronic acid-diol. Tetradentate nitrilotriacetic acid (NTA) is one of the most common commercial ligands for chelating metal ions. The NTA-metal complexes show high and specific affinity toward hexahistidine tags. Such metal complexes have been widely utilized in protein separation and immobilization for diagnostic applications since most of commercialized proteins have been integrated with hexahistidine tags by synthetic or recombinant techniques. This review focused on the development of biosensors with NTA-metal complexes as the binding units, mainly including surface plasmon resonance, electrochemistry, fluorescence, colorimetry, surface-enhanced Raman scattering spectroscopy, chemiluminescence and so on.

Photo-affinity pulling down of low-affinity binding proteins mediated by post-translational modifications

Weak and transient protein-protein interactions (PPIs) mediated by the post-translational modifications (PTMs) play key roles in biological systems. However, technical challenges to investigate the PTM-mediated PPIs have impeded many research advances. In this work, we develop a photo-affinity pull-down assay method to pull-down low-affinity binding proteins, thus for the screen of PTM-mediated PPIs. In this method, the PTM-mediated non-covalent interactions can be converted to the covalent interactions by the photo-activated linkage, so as to freeze frame the low-affinity binding interactions. The fabricated photo-affinity magnetic beads (PAMBs) ensure high specificity and resolution to capture the interacted proteins. Besides, the introduction of PEG passivation layer on PAMB has significantly reduced the non-specific interaction as compared to the traditional pull-down assay. For proof-of-concept, by using this newly developed assay method, we have identified a set of proteins that can interact with a specific methylation site on Flap Endonuclease 1 (FEN1) protein. Less interfering proteins (decreased over 80%) and more proteins sub-classes are profiled as compared to the traditional biotin-avidin pull-down system. Therefore, this new pull-down method may provide a useful tool for the study of low-affinity PPIs, and contribute to the discovery of potential targets for renewed PTM-mediated interactions that is fundamentally needed in biomedical research.

Nanomaterials with enzyme-like characteristics (nanozymes): next-generation artificial enzymes (II)

An updated comprehensive review to help researchers understand nanozymes better and in turn to advance the field.

Bridging exosome and liposome through zirconium–phosphate coordination chemistry: a new method for exosome detection

An exosomes–zirconium–liposomes sandwich structure is proposed to detect exosomes by using zirconium–phosphate coordination chemistry with lower cost, no modified label, and simplicity.