| 1. |
- Ammanath, Aparna Viswanathan, et al.
(författare)
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From an Hsp90 - binding protein to a peptide drug.
- 2022
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Ingår i: microLife. - : Oxford University Press (OUP). - 2633-6693. ; 4
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Tidskriftsartikel (refereegranskat)abstract
- The Lpl proteins represent a class of lipoproteins that was first described in the opportunistic bacterial pathogen Staphylococcus aureus, where they contribute to pathogenicity by enhancing F-actin levels of host epithelial cells and thereby increasing S. aureus internalization. The model Lpl protein, Lpl1 was shown to interact with the human heat shock proteins Hsp90α and Hsp90ß, suggesting that this interaction may trigger all observed activities. Here we synthesized Lpl1-derived peptides of different lengths and identified two overlapping peptides, namely, L13 and L15, which interacted with Hsp90α. Unlike Lpl1, the two peptides not only decreased F-actin levels and S. aureus internalization in epithelial cells but they also decreased phagocytosis by human CD14+ monocytes. The well-known Hsp90 inhibitor, geldanamycin, showed a similar effect. The peptides not only interacted directly with Hsp90α, but also with the mother protein Lpl1. While L15 and L13 significantly decreased lethality of S. aureus bacteremia in an insect model, geldanamycin did not. In a mouse bacteremia model L15 was found to significantly decreased weight loss and lethality. Although the molecular bases of the L15 effect is still elusive, in vitro data indicate that simultaneous treatment of host immune cells with L15 or L13 and S. aureus significantly increase IL-6 production. L15 and L13 represent not antibiotics but they cause a significant reduction in virulence of multidrug-resistant S. aureus strains in in vivo models. In this capacity, they can be an important drug alone or additive with other agents.
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| 2. |
- Javed, Rida, et al.
(författare)
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Enhancement mechanism of P dopant on atomically distributed FeN 4 P-C electrocatalyst over a wide pH range
- 2022
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Ingår i: Electrochimica Acta. - : Elsevier BV. - 0013-4686. ; 436
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Tidskriftsartikel (refereegranskat)abstract
- Heteroatom doping plays an essential role in improving the catalytic performance of electrocatalysts for oxygen reduction reaction (ORR). However, how to regulate heteroatom doping remains a significant challenge. This paper develops an efficient strategy by using a novel versatile chelating ligand to enhance P loading and expose more metal single Fe atom active sites of FeN4P-C catalyst. The electron distribution of active center is considerably changed by P doping, which significantly influences the catalytic ORR performance. The dopant P in the FeN4P-C catalyst induces a small number of d-electrons from t2g-orbitals around the Fermi level, making the interaction between Fe active site and O2 slightly more robust than in the FeN4[sbnd]C catalyst, as studied by DFT calculations. The as-prepared FeN4P-C catalyst exhibits excellent catalytic ORR activity in both acidic (with a half-wave potential of 0.760 V vs. RHE) and basic (with a half-wave potential of 0.885 V vs. RHE) conditions, which are superior to those of the commercial Pt/C (20 wt%) catalyst. Furthermore, this catalyst also demonstrates outstanding stability and good hydrogen peroxide and methanol tolerance. A Zinc-air battery(ZAB) assembled using the cathode catalyst has validated the high performance of this catalyst. This study provides an efficient method for generating well-defined single-atom active sites to improve catalytic performance and paves the way to identify coordinated single metal atom sites for electrocatalysis applications.
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