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The troponin (Tn) is a ternary complex consisting of three subunits TnC, TnI and TnT; molecular disruption of the Tn complex has been recognized as an attractive strategy against neuropathic pain. Here, a self-inhibitory peptide is stripped from the switch region of TnI interaction interface with TnC, which is considered as a lead molecular entity and then used to generate potential peptide disruptors of TnC–TnI interaction based on a rational molecular design protocol. The region is a helical peptide segment capped by N- and C-terminal disorders. Molecular dynamics simulation and binding free energy analysis suggests that the switch peptide can interact with TnC in a structurally and energetically independent manner. Terminal truncation of the peptide results in a number of potent TnC binders with considerably simplified structure and moderately decreased activity relative to the native switch. We also employ fluorescence polarization assays to substantiate the computational findings; it is found that the rationally designed peptides exhibit moderate or high affinity to TnC with dissociation constants K D at micromolar level. [ABSTRACT FROM AUTHOR]

The mitochondrial calcium uniporter (MCU) transports free Ca 2+ into the mitochondrial matrix, maintaining Ca 2+ homeostasis, thus regulates the mitochondrial morphology. Previous studies have indicated that there was closely crosstalk between MCU and mitochondrial fission during the process of ischemia/reperfusion injury. This study constructed a hypoxia reoxygenation model using primary hippocampus neurons to mimic the cerebral ischemia/reperfusion injury and aims to explore the exactly effect of MCU on the mitochondrial fission during the process of ischemia/reperfusion injury and so as the mechanisms. Our results found that the inhibitor of the MCU, Ru360, decreased mitochondrial Ca 2+ concentration, suppressed the expression of mitochondrial fission protein Drp1, MIEF1 and Fis1, and thus improved mitochondrial morphology significantly. Whereas spermine, the agonist of the MCU, had no significant impact compared to the I/R group. This study demonstrated that the MCU regulates the process of mitochondrial fission by controlling the Ca 2+ transport, directly upregulating mitochondrial fission proteins Drp1, Fis1 and indirectly reversing the MIEF1-induced mitochondrial fusion. It also provides new targets for brain protection during ischemia/reperfusion injury. [ABSTRACT FROM AUTHOR]

Organic selenium nanoparticles (SeNPs) are attracting great interest due to their unique properties and potential applications in the food industry. In this study, a novel form of SeNPs was synthesized by using Bacillus licheniformis CGMCC 2876 extracellular polymeric substances (EPS) fermented from waste cane molasses. The morphology of EPS-SeNPs was spherical with an average size of 141.8 nm and a zeta potential of −51.77 mV, and the concentration of Se reached 107.43 mg/g. Additionally, the EPS-SeNPs exhibited good stability in aqueous solution for 7 days and were resistant to the digestion of simulated gastric fluid. The zero-valent Se composition and C–O⋯Se asymmetric stretch were characterized in the EPS-SeNPs. A synthesis mechanism of EPS-SeNPs was hypothesized. Moreover, the biological activities of the EPS-SeNPs synthesized from EPS were evaluated. The EPS-SeNPs exhibit antioxidant activity in scavenging ·OH, DPPH and ·O2− free radicals with abilities <90% in the range of 0.25–4 g/L and inhibit 50% of formed radicals (IC 50) values of 1.18, 13.71 and 1.93 g/L, respectively. EPS-SeNPs also exhibit excellent antibacterial activity, which could inhibit the growth of intestinal pathogenic gram-positive and gram-negative bacteria (>80%) in vitro with the EPS-SeNPs concentrations higher than 1000 μg/mL. • SeNPs were synthesized by using EPS produced by B. licheniformis from cane molasse. • Concentration of Se in the synthesized EPS-SeNPs could reach 107.43 mg/g. • EPS-SeNPs are resistant to the digestion of simulated gastric fluid. • The synthesis mechanism of EPS-SeNPs was hypothesized. • EPS-SeNPs possess antioxidant (<90%) and antibacterial (>80%) activities. [ABSTRACT FROM AUTHOR]