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Nanorods assembled 3D microspheres of TiO2/MnO2 were prepared via a simple one-pot hydrothermal approach. The resultant composite material exhibited remarkable electrocatalytic activity for hydrogen peroxide (H2O2) in comparison to each single component. The electrochemical sensor constructed with TiO2/MnO2 exhibited a linear relationship within the range 0.0001–5.6 mmol·L−1 for H2O2. The limit of detection (LOD) and sensitivity for H2O2 were 0.03 µmol·L−1 (S/N = 3) and 316.6 µA (mmol·L−1)−1 cm−2. Moreover, this sensor can be employed to detect trace amount of H2O2 in serum and urine samples successfully, supporting an insight and strategy for a more sensitive electrochemical sensor. [ABSTRACT FROM AUTHOR]

Protein purification is a basic technology in both biological research and industrial production, and efficient, convenient, economical, and environmentally friendly purification methods have always been pursued. In this study, it was found that alkaline earth metal cations (Mg2+, Ca2+) and alkali metal cations (Li+, Na+, K+) and even nonmetal cations (e.g., NH4+, imidazole, guanidine, arginine, lysine) can precipitate multi-histidine-tagged proteins (at least two tags in a whole protein) at low salts concentrations that are 1–3 orders of magnitude lower than salting-out, and precipitated proteins could be dissolved at moderate concentration of corresponding cation. Based on this finding, a novel cation affinity purification method was developed, which requires only three centrifugal separations to obtain highly purified protein with purification fold similar to that of immobilized metal affinity chromatography. The study also provides a possible explanation for unexpected protein precipitation and reminds researchers to consider the influence of cations on the experimental results. The interaction between histidine-tagged proteins and cations may also have broad application prospects. Key points: • Histidine-tagged proteins can be precipitated by low-concentrations common cations • A novel nonchromatographic protein purification method was developed • Purified protein can be obtained in pellet form by only three centrifugations [ABSTRACT FROM AUTHOR]

In this study, nitrilase (Nit) was immobilized in zeolite imidazole framework-90 (ZIF-90) by one-pot biomimetic mineralization strategy. The structure, morphology and functional groups of ZIF-90 and immobilized enzyme Nit@ZIF-90 were characterized by scanning electron microscopy (SEM)/energy-dispersive X-ray spectroscopy (EDX), transmission electron microscopy (TEM), X-ray diffraction (XRD), thermogravimetric analysis (TGA) and Fourier transform infrared spectroscopy (FT-IR). Circular dichroism (CD) proved that the immobilized method of encapsulation in ZIF-90 could effectively maintain the intrinsic conformation of Nit. Meanwhile, the stability and reusability of Nit@ZIF-90 were systematically evaluated. Compared with the free enzyme, the thermal, pH and organic solvents stability of Nit@ZIF-90 were significantly increased. Further, Nit@ZIF-90 exhibited better reusability during the hydrolysis of acrylonitrile and retained 48.34% of the initial activity after 10 cycles. Besides, the Ni@ZIF-90 had preferable storage stability, which showed a high degree of residual activity (more than 64 %) after storage at 4 °C for 7 d. The improved stability and reusability of the Nit@ZIF-90 implied that it could be used as a potential effective biocatalyst for hydrolysis of nitrile compounds in industrial application. [ABSTRACT FROM AUTHOR]

To study the effect of SpyTag/SpyCatcher cyclization on stability and refolding of protein, we constructed a cyclized green fluorescent protein (SRGFP) and its derivative to act as a linear structure control (L-SRGFP). SRGFP and L-SRGFP showed similar fluorescence characteristics to the wild-type GFP, while compared with GFP and L-SRGFP, the thermal stability and denaturation resistance of SRGFP were improved. The refolding efficiencies of these three denatured proteins were investigated under different pH, temperature and initial protein concentration conditions, and it was found that SRGFP was superior to GFP and L-SRGFP in terms of refolding yield and refolding speed. In the pH range of 8.0–8.5, SRGFP could basically recover all fluorescence, while GFP and L-SRGFP recovered only about 87.52% and 88.58%. When refolded at a high temperature (37 °C), SRGFP still recovered 85.27% of the fluorescence, whereas GFP and L-SRGFP recovered only around 69.43% and 68.45%. At a high initial protein concentration (5 mg/mL), the refolding yield of SRGFP was about 15% higher than that of both GFP and L-SRGFP. These results suggest that the introduction of SpyRing structure (head-to-tail cyclization via SpyTag and SpyCatcher) improved the protein's stability and facilitated the refolding of denatured protein. [ABSTRACT FROM AUTHOR]

Aims: The mechanism by which species diversity drives productivity in different ecosystems is controversial, possibly due to the confounding effects of key environmental variables. Karst ecosystems are fragile and are at great risk of species loss. In these ecosystems, soil depth is a key driver of community diversity and productivity. However, the influence of soil depth on the relationship between species diversity and productivity in karst ecosystems remains unclear. Methods: We established artificial karst herbaceous communities with different soil depths and species richness levels and determined how two biodiversity effects—complementarity effect (effect of positive interactions among species) and selection effect (effect due to dominance of productive species)—contributed to productivity. Results: Soil depth, species diversity, and different species combinations were significant predictors of productivity. Species diversity significantly positively affected productivity at all three soil depths, with the effect size of species diversity being the greatest in medium-depth soil. Net diversity effects were greater than 0 in all multi-species communities, indicating that complementarity and selection effects both positively influenced productivity. However, complementarity effect had a greater contribution to productivity than selection effect in all multi-species communities. Furthermore, the contribution of complementarity effect increased with increasing soil depth, while that of selection effect decreased. Conclusions: Our result indicate that both soil depth and species diversity need be considered simultaneously in maintaining karst herbaceous community productivity. Moreover, complementarity effect is the major mechanism by which diversity increases community productivity, particularly in shallow soil. Thus, the more attention should be paid to promoting species diversity with the decreasing of soil depth for adequately preserve karst key functions such as herbaceous community productivity. [ABSTRACT FROM AUTHOR]

Iron (Fe) deficiency chlorosis (IDC) is a major nutritional disorder in fruit trees grown on calcareous soils. As a peach rootstock, 'GF677' (Prunus dulcis Miller × P. persica (L.) Batsch) has great tolerance to Fe deficiency, but the molecular mechanisms of 'GF677' that support the process of iron deficiency chlorosis tolerance are still unknown. In this study, the key factors for differential iron deficiency chlorosis tolerance in two contrasting rootstocks (IDC-tolerant: 'GF677', IDC-susceptible: 'Maotao' (P. persica)) were investigated. 'GF677' exhibited greater Fe transfer and accumulation capacities when compared with 'Maotao', and the analysis of photosynthetic pigments, related precursors, and antioxidative enzyme activities further demonstrated that 'GF677' was more tolerant to IDC when compared with 'Maotao'. Furthermore, comparative transcriptome analysis revealed differential expression in many genes involved in iron transport and storage, and in photosynthesis recovery. These results suggest that the greater IDC tolerance of 'GF677' can be attributed to the greater expression of key genes related to specific Fe transporters, defense systems, photosynthetic recovery, and/or special proteins. [ABSTRACT FROM AUTHOR]

Multiple myeloma (MM) is a form of clonal plasma cell malignancy that associates with clinical manifestations such as anemia, hypercalcemia, bone pain, and renal impairment. Approximately 20–50% of MM patients at initial diagnosis experience renal injury, a vital complication that significantly influences prognosis and quality of life. This review seeks to clarify the multifaceted mechanisms of renal injury in MM, scrutinizing the pathogenic role of monoclonal proteins, the impact of hypercalcemia, and direct renal infiltration by plasma cells. Furthermore, it evaluates current diagnostic approaches, reviews management strategies, and highlights potential avenues for future research. By incorporating the latest scientific evidence and insights, this article aims to provide a comprehensive understanding of MM-associated renal impairment, offering a valuable resource for researchers and clinicians in handling this complex complication. [ABSTRACT FROM AUTHOR]