Homologous Overexpression of Tyrosinase in Trichoderma reesei and Its Application in Glycinin Cross-Linking.

Tyrosinase is capable of oxidizing tyrosine residues in proteins, leading to intermolecular protein cross-linking, which could modify the protein network of food and improve the texture of food. To obtain the recombinant tyrosinase with microbial cell factory instead of isolation tyrosinase from the mushroom Agaricus bisporus, a TYR expression cassette was constructed in this study. The expression cassette was electroporated into Trichoderma reesei Rut-C30 and integrated into its genome, resulting in a recombinant strain C30-TYR. After induction with microcrystalline cellulose for 7 days, recombinant tyrosinase could be successfully expressed and secreted by C30-TYR, corresponding to approximately 2.16 g/L tyrosinase in shake-flask cultures. The recombinant TYR was purified by ammonium sulfate precipitation and gel filtration, and the biological activity of purified TYR was 45.6 U/mL. The purified TYR could catalyze the cross-linking of glycinin, and the emulsion stability index of TYR-treated glycinin emulsion was increased by 30.6% compared with the untreated one. The cross-linking of soy glycinin by TYR resulted in altered properties of oil-in-water emulsions compared to emulsions stabilized by native glycinin. Therefore, cross-linking with this recombinant tyrosinase is a feasible approach to improve the properties of protein-stabilized emulsions and gels.

The structural pathology for hypophosphatasia caused by malfunctional tissue non-specific alkaline phosphatase.

Hypophosphatasia (HPP) is a metabolic bone disease that manifests as developmental abnormalities in bone and dental tissues. HPP patients exhibit hypo-mineralization and osteopenia due to the deficiency or malfunction of tissue non-specific alkaline phosphatase (TNAP), which catalyzes the hydrolysis of phosphate-containing molecules outside the cells, promoting the deposition of hydroxyapatite in the extracellular matrix. Despite the identification of hundreds of pathogenic TNAP mutations, the detailed molecular pathology of HPP remains unclear. Here, to address this issue, we determine the crystal structures of human TNAP at near-atomic resolution and map the major pathogenic mutations onto the structure. Our study reveals an unexpected octameric architecture for TNAP, which is generated by the tetramerization of dimeric TNAPs, potentially stabilizing the TNAPs in the extracellular environments. Moreover, we use cryo-electron microscopy to demonstrate that the TNAP agonist antibody (JTALP001) forms a stable complex with TNAP by binding to the octameric interface. The administration of JTALP001 enhances osteoblast mineralization and promoted recombinant TNAP-rescued mineralization in TNAP knockout osteoblasts. Our findings elucidate the structural pathology of HPP and highlight the therapeutic potential of the TNAP agonist antibody for osteoblast-associated bone disorders.

Co-Delivery of Paclitaxel and PLK1-Targeted siRNA Using Aptamer-Functionalized Cationic Liposome for Synergistic Anti-Breast Cancer Effects In Vivo.

Cancer cells can develop in several ways to escape from death induced by chemotherapeutic agents, thereby weakening the anti-tumor efficacy of single-target chemotherapy. Therefore, the efficacy of conventional chemotherapy hits a single target in tumor cells subject to strict limits. In this article, an AS1411 aptamer-functionalized liposome is prepared, which can simultaneously deliver paclitaxel (PTX) and siRNA into MCF-7 cells in vitro and in vivo. The simultaneous delivery of PTX and siRNA synergistically increased the number of apoptotic cells and reduced angiogenesis. This delivery method exhibited significant advantages over combined delivery of PTX and siRNA separately by different liposomal drug delivery systems. Therefore, the simultaneous delivery of PTX and PLK1-targeted siRNA using AS1411 aptamer-functionalized liposome may have good potential clinical value for the therapy of breast cancer. Nanomedicine based on simultaneous delivery of chemotherapy drugs and siRNA gene provides an effective platform for improving tumor treatment methods.

Vincristine-Loaded and sgc8-Modified Liposome as a Potential Targeted Drug Delivery System for Treating Acute Lymphoblastic Leukemia.

Cytotoxic compounds vincristine sulphate (VCR) is widely used to against hemato-oncology, and especially the acute lymphoblastic leukemia (ALL). However, VCR's full therapeutic potential has been limited by its dose-limiting neurotoxicity, classically resulting in autonomic and peripheral sensory-motor neuropathy. Therefore, we developed a targeted liposomal drug delivery system (sgc8/VCR-Lipo) for improving the therapeutic effects of VCR against leukemia and reducing its systematic adverse effects. sgc8/VCR-Lipo could specifically bind to CCRF-CEM cells and significantly inhibit proliferation of cancer cells in vitro and tumor growth in vivo. The sgc8/VCR-Lipo nanoparticles may improve the anti-tumor efficacy of VCR and reduce side effects induced by non-specific drug release. These results suggest that our findings provide scientific evidence for developing novel aptamer-based targeted drug delivery systems for leukemia treatment.