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Metal ions like Cu 2+ and Zn 2+ have been shown to impact protein misfolding pathways in neurodegenerative proteinopathies like Alzheimer's and Parkinson's. Also, due to their strong interaction with Ubiquitin, they interfere in degradation of misfolded proteins by impairing the ubiquitin-proteasome system (UPS). In this work, we have studied the interaction of these metal ions with a small Ubiquitin like post-translation modifier SUMO1, which is known to work co-operatively with Ubiquitin to regulate UPS system. Between Cu 2+ and Zn 2+ , the former binds more strongly with SUMO1 as determined using fluorescence spectroscopy. SUMO1 aggregates, forming trimer and higher oligomers in presence of Cu 2+ ions which were characterized using gel electrophoresis, Bradford assay, and transmission electron microscopy. Chemical shift analysis using 15 N/ 1 H based NMR spectroscopy revealed that SUMO1 retains its structural fold in its trimeric state. Cu 2+ induced paramagnetic quenching and Zn 2+ induced chemical shift perturbation of 15 N- 1 H cross-peaks were used to identify their respective binding sites in SUMO1. Binding sites so obtained were further validated with molecular dynamics studies. Our findings provide structural insights into the SUMO1-Cu 2+ /Zn 2+ interaction, and its impact on aggregation of SUMO1 which might affect its ability to modify functions of target proteins., (Copyright © 2020 Elsevier B.V. All rights reserved.)

The silica-resacetophenone (SiO2-RATP) nanoparticles were used as a new sorbent for extraction of trace amounts of Pb(II) by batch technique. Conditions of the analysis such as preconcentration factor, effect of pH, sample volume, shaking time, elution conditions and effects of interfering ions for the recovery of analyte were investigated. The adsorption capacity of nanometer SiO2-RATP was found to be 167.24 μmol/g at optimum pH and the detection limit (3σ) was 0.58 μg/L. The adsorption equilibrium of Pb(II) on nanometer SiO2-RATP was achieved in 20 min. Adsorbed Pb(II) was easily eluted with 5 mL of 0.5 M hydrochloric acid. The maximum preconcentration factor was 60. The method was applied for the determination of trace amounts of Pb(II) in various natural water rivers. [ABSTRACT FROM AUTHOR]

• The MSPE easy to filtration, high surface area, good adsorption capacity, low toxicity and easy for separation so no need of centrifuge. • Silica is non toxic, biocompatible and easy to synthesize as well as high temperature stability nanoparticles. • The main significance of synthesized nanomaterials is its high sensitivity, selectivity for Cd(II) metal ion. Magnetic nano structured materials provide new functionalities not found in their individual nano components. Removal and recovery of Cd(II) from aqueous solution was investigated using SiO 2 @Fe 3 O 4 -SB nano-hybrid materials. To enhance the potential of adsorbent material, we explored a new type Schiff's base functionalized silica coated iron-oxide nano-hybrids (SiO 2 @Fe 3 O 4 -SB). The combination of both adsorption and magnetic separation properties were employed selectively for removal and recovery of Cd(II) from water and wastewater samples. Effect of different parameters influencing adsorption of Cd(II) for instance; interference of distinct cations and anions, effect of pH, concentration and volume of eluent, amount of adsorbent and ultra-sonication time were appraised and examined. The adsorbed Cd(II) was then desorbed and determined spectrophotometrically. The synthesized material was characterized with UV–vis spectroscopy, XRD, FTIR and TEM. The Limit of Detection under optimized conditions for Cd (II) in water samples was determined to be 0.741 μg L−1 using synthesized nano-hybrids. [ABSTRACT FROM AUTHOR]