Recent developments in promiscuous enzymatic reactions for carbon-nitrogen bond formation

A Bimetallic Nanozyme Synergistic Effect-Driven Enzyme Cascade Nanoreactor for Instant Immunoassay

This study presents a colorimetric sensor for cancer screening utilizing the bifunctional enzyme activity of NiCo Prussian blue analogue (PBA), a PBA material. By introducing oxygen vacancies and employing a dual-metal doping strategy, NiCo PBA overcomes the limitations in catalytic activity observed in single-metal-doped materials (such as Ni PBA and Co PBA), significantly enhancing both peroxidase-like (POD) and catalase-like (CAT) activities. Compared to single-metal-doped Ni PBA and Co PBA, NiCo PBA exhibited a 30.08-fold increase in POD activity and a 4.83-fold increase in CAT activity, demonstrating higher sensitivity in carcinoembryonic antigen (CEA) detection. By integrating NiCo PBA with a cascade catalytic reaction principle, we developed a highly efficient and sensitive CEA detection method. NiCo PBA was utilized as a catalytic material in this method. Under the action of glucose oxidase, the decomposition of hydrogen peroxide was catalyzed by NiCo PBA, and oxygen was generated. Furthermore, a blue flocculent substance was produced when NiCo PBA was reacted with a chromogenic substrate. Through mutual verification by these two methods, the quantitative determination of CEA in serum samples was achieved. The experimental results demonstrated that the POD-like activity detection range was 0.2-50 ng mL-1, with a limit of detection (LOD) of 0.061 ng mL-1, while the CAT-like activity detection range was 0.1-20 ng mL-1, with an LOD of 0.028 ng mL-1. The sensitivity of this method was substantially increased compared to monometallic materials. Furthermore, this strategy possesses good scalability and can be adapted for the detection of various analytes by replacing different recognition units, providing an efficient detection platform for early cancer screening.

Enzyme loading in the support and medium composition during immobilization alter activity, specificity and stability of octyl agarose-immobilized Eversa Transform

Eversa Transform (ETL) was immobilized on octyl agarose beads at two different enzymes loadings (1 mg/g and 15 mg/g) under 18 different conditions, including different pH values, buffers, additives (different solvents, Ca2+, NaCl). Their activity was analyzed at pH 5 and 7 with p-nitrophenyl butyrate and at pH 5 with triacetin, determining also its stability at pH 5 and 7 (in different media). Ca2+ stabilized ETL biocatalysts while phosphate destabilized them. The overloaded biocatalysts were generally less stable and with a lower specific activity than the lowly loaded biocatalyst. Results show that enzyme activity (even by a 3 fold factor) and stability of the immobilized enzyme may be tailored by controlling the immobilization conditions, but the effects of the immobilization conditions on activity depend on the substrate and conditions of activity determination, the effects on stability depend on the inactivation conditions. Moreover, the enzyme loading of the biocatalysts defines the effects of the immobilization conditions, and there are clear interactions between immobilization conditions (e.g., immobilization pH determines the effect of the presence of NaCl). These suggest that the extrapolation of the results obtained with one substrate under one condition to other conditions can lead to wrong decisions.

Recent advances in biocatalytic C-N bond-forming reactions

Molecules containing C-N bonds are of paramount importance in a diverse array of organic-based materials, natural products, pharmaceutical compounds, and agricultural chemicals. Biocatalytic C-N bond-forming reactions represent powerful strategies for producing these valuable targets, and their significance in the field of synthetic chemistry has steadily increased over the past decade. In this review, we provide a concise overview of recent advancements in the development of C-N bond-forming enzymes, with a particular emphasis on the inherent chemistry involved in these enzymatic processes. Overall, these enzymatic systems have proven their potential in addressing long-standing challenges in traditional small-molecule catalysis.