Amyloidogenic human lysozyme variants deposit in cells and cause systemic amyloidosis. We recently observed that such lysozymes accumulate in the endoplasmic reticulum (ER) with the ER chaperone GRP78/BiP, accompanying the ER stress response. Here we investigated the region of lysozyme that is critical to its association with GRP78/BiP. In addition to the above-mentioned variants of lysozyme, we constructed lysozyme truncation or substitution mutants. These were co-expressed with GRP78/BiP (tagged with FLAG) in cultured human embryonic kidney cells, which were analyzed by western blotting and immunocytochemistry using anti-lysozyme and anti-FLAG antibodies. The amyloidogenic variants were confirmed to be strongly associated with GRP78/BiP as revealed by the co-immunoprecipitation assay, whereas N-terminal mutants pruned of 1-41 or 1-51 residues were found not to be associated with the chaperone. Single amino acid substitutions for the leucine array along the α-helices in the N-terminal region resulted in wild-type lysozyme remaining attached to GRP78/BiP. These mutations also tended to show lowered secretion ability. We conclude that the N-terminal α-helices region of the lysozyme is pivotal for its strong adhesion to GRP78/BiP. We suspect that wild-type lysozyme interacts with the GRP at this region as a step in the proper folding monitored by the ER chaperone.
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http://dx.doi.org/10.7150/ijbs.13710 | DOI Listing |
J Chem Inf Model
January 2025
Department of Computational Chemistry, Lund University, Chemical Centre, P.O. Box 124, Lund SE-221 00, Sweden.
Alchemical free-energy perturbation (FEP) is an accurate and thermodynamically stringent way to estimate relative energies for the binding of small ligands to biological macromolecules. It has repeatedly been pointed out that a single simulation normally stays near the starting point in phase space and therefore underestimates the uncertainty of the results. Therefore, it is better to run an ensemble of independent simulations.
View Article and Find Full Text PDFActa Crystallogr A Found Adv
March 2025
Nanostructures Research Laboratory, Japan Fine Ceramics Center, 2-4-11 Mustuno, Atsuta-ku, Nagoya, 456-8587, Japan.
Due to the short de Broglie wavelength of electrons compared with X-rays, the curvature of their Ewald sphere is low, and individual electron diffraction patterns are nearly flat in reciprocal space. As a result, a reliable unit-cell determination from a set of randomly oriented electron diffraction patterns, an essential step in serial electron diffraction, becomes a non-trivial task. Here we describe an algorithm for unit-cell determination from a set of independent electron diffraction patterns, as implemented in the program PIEP (Program for Interpreting Electron diffraction Patterns), written in the early 1990s.
View Article and Find Full Text PDFBull Entomol Res
January 2025
Laboratory of ecological parasitology, Institute of Systematics and Ecology of Animals SB RAS, Novosibirsk, Russia.
The effect of on the viability and antimicrobial activity of the ectoparasitoid was evaluated in laboratory experiments. Two lines of the parasitoid, -infected (W+) and -free (W-), were used. Parasitoid larvae were fed with a host orally infected with a sublethal dose of (Bt) and on the host uninfected with Bt.
View Article and Find Full Text PDFProtein Sci
February 2025
Graduate School of Engineering, Osaka University, Osaka, Japan.
Amyloid fibril formation of α-synuclein (αSN) is a hallmark of synucleinopathies. Although the previous studies have provided numerous insights into the molecular basis of αSN amyloid formation, it remains unclear how αSN self-assembles into amyloid fibrils in vivo. Here, we show that αSN amyloid formation is accelerated in the presence of two macromolecular crowders, polyethylene glycol (PEG) (MW: ~10,000) and dextran (DEX) (MW: ~500,000), with a maximum at approximately 7% (w/v) PEG and 7% (w/v) DEX.
View Article and Find Full Text PDFVet Immunol Immunopathol
January 2025
Fisheries College of Guangdong Ocean University, Guangdong Provincial Key Laboratory of Aquatic Animal Disease Control and Healthy Culture, Key Laboratory of Control for Diseases of Aquatic Economic Animals of Guangdong Higher Education Institute, Zhanjiang, China. Electronic address:
Vibrio alginolyticus is a serious aquaculture bacterial pathogen, which is widely distributed in the ocean and rivers, and cause vibriosis in aquaculture. Therefore, it is imperative to develop effective vaccine to prevent vibriosis. In this study, the efficacy of gr deletion strain (Δgr) of V.
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