Glycosylphosphatidylinositol (GPI)-anchored proteins have been identified in all eukaryotes. In fungi, structural and biosynthetic studies of GPIs have been restricted to the yeast Saccharomyces cerevisiae. In this article, four GPI-anchored proteins were purified from a membrane preparation of the human filamentous fungal pathogen Aspergillus fumigatus. Using new methodology applied to western blot protein bands, the GPI structures were characterized by ES-MS, fluorescence labeling, HPLC, and specific enzymatic digestions. The phosphatidylinositol moiety of the A. fumigatus GPI membrane anchors was shown to be an inositol-phosphoceramide containing mainly phytosphingosine and monohydroxylated C24:0 fatty acid. In constrast to yeast, only ceramide was found in the GPI anchor structures of A. fumigatus, even for Gel1p, a homolog of Gas1p in S. cerevisiae that contains diacylglycerol. The A. fumigatus GPI glycan moiety is mainly a linear pentomannose structure linked to a glucosamine residue: Manalpha1-3Manalpha1-2Manalpha1-2Manalpha1-6Manalpha1-4GlcN.
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http://dx.doi.org/10.1093/glycob/cwg004 | DOI Listing |
ACS Appl Mater Interfaces
January 2025
State Key Laboratory of Fine Chemicals, Research and Development Center of Membrane Science and Technology, School of Chemical Engineering, Dalian University of Technology, Dalian 116024, China.
The electrocatalytic nitrogen reduction reaction (eNRR) is an attractive strategy for the green and distributed production of ammonia (NH); however, it suffers from weak N adsorption and a high energy barrier of hydrogenation. Atomically dispersed metal dual-site catalysts with an optimized electronic structure and exceptional catalytic activity are expected to be competent for knotty hydrogenation reactions including the eNRR. Inspired by the bimetallic FeMo cofactor in biological nitrogenase, herein, an atomically dispersed FeMo dual site anchored in nitrogen-doped carbon is proposed to induce a favorable electronic structure and binding energy.
View Article and Find Full Text PDFInt J Mol Sci
December 2024
Institute of Food Technology, Department of Food Science and Technology, BOKU University, 1190 Vienna, Austria.
is a potential bacterial cell factory to develop delivery systems for vaccines and therapeutic proteins. Much progress has been made in applications using engineered against, e.g.
View Article and Find Full Text PDFProc Natl Acad Sci U S A
January 2025
Department of Biophysics, University of Texas Southwestern Medical Center, Dallas, TX 75390.
Neurotransmitter release is triggered in microseconds by Ca-binding to the Synaptotagmin-1 C-domains and by SNARE complexes that form four-helix bundles between synaptic vesicles and plasma membranes, but the coupling mechanism between Ca-sensing and membrane fusion is unknown. Release requires extension of SNARE helices into juxtamembrane linkers that precede transmembrane regions (linker zippering) and binding of the Synaptotagmin-1 CB domain to SNARE complexes through a "primary interface" comprising two regions (I and II). The Synaptotagmin-1 Ca-binding loops were believed to accelerate membrane fusion by inducing membrane curvature, perturbing lipid bilayers, or helping bridge the membranes, but SNARE complex binding through the primary interface orients the Ca-binding loops away from the fusion site, hindering these putative activities.
View Article and Find Full Text PDFPLoS Negl Trop Dis
January 2025
Department of Pediatrics, National School of Tropical Medicine, Baylor College of Medicine, Houston, Texas, United States of America.
Background: The antigen Na-GST-1, expressed by the hookworm Necator americanus, plays crucial biochemical roles in parasite survival. This study explores the development of mRNA vaccine candidates based on Na-GST-1, building on the success of recombinant Na-GST-1 (rNa-GST-1) protein, currently assessed as a subunit vaccine candidate, which has shown promise in preclinical and clinical studies.
Methodology/findings: By leveraging the flexible design of RNA vaccines and protein intracellular trafficking signal sequences, we developed three variants of Na-GST-1 as native (cytosolic), secretory, and plasma membrane-anchored (PM) antigens.
Biochim Biophys Acta Biomembr
January 2025
Land and Food Systems, University of British Columbia, Vancouver, Canada; Faculty of Agricultural, Life and Environmental Sciences, University of Alberta, Edmonton, Canada. Electronic address:
The Solanum tuberosum (common potato) plant specific insert (StPSI) is an antimicrobial protein domain that exhibits membrane-disrupting and membrane-fusing activity upon dimerization at acidic pH, activity proposed to involve electrostatic attraction and membrane anchoring mediated by specific positively-charged and conserved tryptophan residues, respectively. This study is the first to employ an in silico mutagenesis approach to clarify the structure-function relationship of a plant specific insert (PSI), where ten rationally-mutated StPSI variants were investigated using all-atom and coarse-grained molecular dynamics. The tryptophan (W) residue at position 18 (W18) of wild-type StPSI was predicted to confer structural flexibility to the dimer and mediate a partial separation of the assembled monomers upon bilayer contact, while residues including W77 and the lysine (K) residue at position 83 (K83) were predicted to stabilize secondary structure and influence association with the model membrane.
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