High and low levels of lipid-induced protein oxidation (tuned by the addition of 0%-8.4% water) were investigated in oleogels, using excitation-emission matrix (EEM) fluorescence spectroscopy, coupled with a partial least-squares (PLS) regression and lipid hydroperoxide data. In high-level oxidation models, the intrinsic tryptophan fluorescence decreased and the emission maxima increased from 352.5 to 356.0 nm indicating the presence of protein modifications, which was further supported by size-exclusion chromatography. PLS recognized 3 latent components, with several excitation-emission points of interest. These apparent compounds include a region associated with radical mediated protein modifications (approximately 325 and 410 nm), lipid oxidation product adducts (approximately 350 nm and 420-425 nm), and malondialdehyde adducts (approximately 375 and 425 nm). The separate evaluation of these apparent compounds, at a 420 nm emission, indicated that lipid oxidation promotes protein lipid adduct fluorescence at high water levels, rather than radical mediated protein fluorescence.
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http://dx.doi.org/10.1021/acs.jafc.0c02911 | DOI Listing |
ACS Appl Bio Mater
January 2025
Department of Chemistry, Indian Institute of Technology Palakkad, Palakkad, Kerala 678 623, India.
The aggregation of proteins, peptides and amino acids has been a keen subject of interest owing to their implications in metabolic disorders. In this work, we investigated the self-aggregation of the unmodified aromatic amino acid l-tryptophan (Trp) into unusual spherical microstructures. Using fluorescence spectroscopy and field emission scanning electron microscopy (FE-SEM), we detail the time-dependent transformation of monomeric tryptophan into spherical aggregates with distinct fluorescence characteristics (λ = 345 nm, λ = 430 nm) compared to the monomer.
View Article and Find Full Text PDFProc Natl Acad Sci U S A
January 2025
Department of Chemical and Biological Engineering, University of Colorado, Boulder, CO 80305.
Immunological interventions, like vaccinations, are enabled by the predictive control of humoral responses to novel antigens. While the development trajectories for many broadly neutralizing antibodies (bnAbs) have been measured, it is less established how human subtype-specific antibodies develop from their precursors. In this work, we evaluated the retrospective development trajectories for eight anti-SARS-CoV-2 Spike human antibodies (Abs).
View Article and Find Full Text PDFProtein Sci
February 2025
Laboratory MIVEGEC (Univ. Montpellier, CNRS, IRD), French National Center for Scientific Research (CNRS), Montpellier, France.
Biochemistry textbooks describe eukaryotic mRNAs as monocistronic. However, increasing evidence reveals the widespread presence and translation of upstream open reading frames preceding the "main" ORF. DNA and RNA viruses infecting eukaryotes often produce polycistronic mRNAs and viruses have evolved multiple ways of manipulating the host's translation machinery.
View Article and Find Full Text PDFDev Dyn
January 2025
Department of Medicine, Michigan State University College of Human Medicine, East Lansing, Michigan, USA.
Disruption of extracellular pH and proton-sensing can profoundly impact cellular and protein functions, leading to developmental defects. To visualize changes in extracellular pH in the developing embryo, we generated a zebrafish transgenic line that ubiquitously expresses the ratiometric pH-sensitive fluorescent protein pHluorin2, tethered to the extracellular face of the plasma membrane using a glycosylphosphatidylinositol (GPI) anchor. Monitoring of pHluorin2 with ratiometric fluorescence revealed dynamic and discrete domains of extracellular acidification over the first 72 h of embryonic development.
View Article and Find Full Text PDFLuminescence
January 2025
School of Chemistry and Chemical Engineering, Nanchang University, Nanchang, Jiangxi, China.
Tetrachlorobisphenol A (TCBPA) is a kind of fire retardant extensively used in our life, but it can accumulate in organisms and potentially have toxic effects. Transferrin (TF) is a glycoprotein predominantly present in the blood plasma, serving as an essential mediator for the transportation of iron and other small molecules. In our study, various techniques including multi-spectroscopic and molecular docking were employed to examine the interaction between TCBPA and TF.
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