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- De Oliveira, Danilo Hirabae, et al.
(författare)
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Silk Assembly against Hydrophobic Surfaces?Modeling and Imaging of Formation of Nanofibrils
- 2023
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Ingår i: ACS Applied Bio Materials. - : AMER CHEMICAL SOC. - 2576-6422. ; 6:3, s. 1011-1018
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Tidskriftsartikel (refereegranskat)abstract
- A detailed insight about the molecular organization behind spider silk assembly is valuable for the decoding of the unique properties of silk. The recombinant partial spider silk protein 4RepCT contains four poly-alanine/glycine-rich repeats followed by an amphiphilic C-terminal domain and has shown the capacity to self-assemble into fibrils on hydrophobic surfaces. We herein use molecular dynamic simulations to address the structure of 4RepCT and its different parts on hydrophobic versus hydrophilic surfaces. When 4RepCT is placed in a wing arrangement model and periodically repeated on a hydrophobic surface, fi-sheet structures of the poly-alanine repeats are preserved, while the CT part is settled on top, presenting a fibril with a height of similar to 7 nm and a width of similar to 11 nm. Both atomic force microscopy and cryo-electron microscopy imaging support this model as a possible fibril formation on hydrophobic surfaces. These results contribute to the understanding of silk assembly and alignment mechanism onto hydrophobic surfaces.
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| 2. |
- de Rivero Vaccari, J. P., et al.
(författare)
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Mechanism of action of IC 100, a humanized IgG4 monoclonal antibody targeting apoptosis-associated speck-like protein containing a caspase recruitment domain (ASC)
- 2023
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Ingår i: Translational Research. - : Elsevier BV. - 1931-5244 .- 1878-1810. ; 251, s. 27-40
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Tidskriftsartikel (refereegranskat)abstract
- Inflammasomes are multiprotein complexes of the innate immune response that recognize a diverse range of intracellular sensors of infection or cell damage and recruit the adaptor protein apoptosis-associated speck-like protein containing a caspase recruitment domain (ASC) into an inflammasome signaling complex. The recruitment, polymerization and cross-linking of ASC is upstream of caspase-1 activation and interleukin-1β release. Here we provide evidence that IC 100, a humanized IgG4κ monoclonal antibody against ASC, is internalized into the cell and localizes with endosomes, while another part is recycled and redistributed out of the cell. IC 100 binds intracellular ASC and blocks interleukin-1β release in a human whole blood cell inflammasome assay. In vitro studies demonstrate that IC 100 interferes with ASC polymerization and assembly of ASC specks. In vivo bioluminescence imaging showed that IC 100 has broad tissue distribution, crosses the blood brain barrier, and readily penetrates the brain and spinal cord parenchyma. Confocal microscopy of fluorescent-labeled IC 100 revealed that IC 100 is rapidly taken up by macrophages via a mechanism utilizing the Fc region of IC 100. Coimmunoprecipitation experiments and confocal immunohistochemistry showed that IC 100 binds to ASC and to the atypical antibody receptor Tripartite motif-containing protein-21 (TRIM21). In A549 WT and TRIM21 KO cells treated with either IC 100 or IgG4κ isotype control, the levels of intracellular IC 100 were higher than in the IgG4κ-treated controls at 2 hours, 1 day and 3 days after administration, indicating that IC 100 escapes degradation by the proteasome. Lastly, electron microscopy studies demonstrate that IC 100 binds to ASC filaments and alters the architecture of ASC filaments. Thus, IC 100 readily penetrates a variety of cell types, and it binds to intracellular ASC, but it is not degraded by the TRIM21 antibody-dependent intracellular neutralization pathway.
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