Pertussis toxin was purified to homogeneity from a 2-day culture supernatant of Bordetella pertussis by stepwise elution from three columns of, consecutively, Blue Sepharose, phenyl Sepharose, and hydroxyapatite. The toxin was eluted from Blue Sepharose and hydroxyapatite by high ionic strength and from phenyl Sepharose with low ionic strength and with 17% glycerol. Toxin fractions from one chromatographic column were immediately charged on the next column, saving laborious and time-consuming concentration or dialysis steps. Based on peptide composition (after sodium dodecyl sulfate-polyacrylamide gel electrophoresis) and on HPLC profile (under nondenaturing conditions), the toxin was already practically pure after two steps, the third hydroxyapatite column serving only to separate the whole native toxin from any free S1 subunit. Recovery was estimated from the capacity of the preactivated toxin (and any preexisting free S1 subunit) to catalyze the ADP-ribosylation of the guanine nucleotide binding protein Ni in rat pancreatic plasma membranes: of the total capacity initially present in the culture medium, 23% could be recovered as pure native toxin with the present procedure. Besides, the nondenaturing HPLC method used to check the purity of the native toxin appeared to be superior to classical acidic polyacrylamide gel electrophoresis.
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http://dx.doi.org/10.1016/0003-2697(86)90360-x | DOI Listing |
mSphere
January 2025
Department of Biological Sciences, University of Pittsburgh, Pittsburgh, Pennsylvania, USA.
Unlabelled: During infection, bacterial pathogens rely on secreted virulence factors to manipulate the host cell. However, in gram-positive bacteria, the molecular mechanisms underlying the folding and activity of these virulence factors after membrane translocation are not clear. Here, we solved the protein structures of two secreted parvulin and two secreted cyclophilin-like peptidyl-prolyl isomerase (PPIase) ATP-independent chaperones found in gram-positive streptococcal species.
View Article and Find Full Text PDFMolecules
January 2025
Department of Food Biofunctionality (140b), Institute of Nutritional Sciences, University of Hohenheim, D-70599 Stuttgart, Germany.
Phenolic compounds have antiglycation activity, but the changes occurring during thermal treatment (TT) in these activities are not completely understood. The effects of the extraction conditions of (poly)phenols from fruits, before and after TT, on their antioxidant and antiglycation effects were assessed. (Poly)phenol-enriched extracts (PEEs) from raw and TT (90 °C, 1 h) were extracted using three solvent mixtures (ethanol/water/acetic acid) with increasing water content (0, 24, and 49%) and three solvent-to-solid ratios (5, 10, and 20 mL/g).
View Article and Find Full Text PDFJ Neural Transm (Vienna)
January 2025
Institut für Zellbiochemie, OE 4310, Medizinische Hochschule Hannover, 30623, Hannover, Germany.
Botulinum neurotoxins (BoNT) are established biopharmaceuticals for neuromuscular and secretory conditions based on their ability to block neurotransmitter release from neurons by proteolyzing specific soluble N-ethylmaleimide-sensitive factor attachment protein receptor (SNARE) proteins. Recently, a mutant catalytic domain of serotype E (LC/E) exhibiting 16 mutations was reported to cleave the phosphatase and tensin homolog (PTEN). This molecule represents an attractive new target in neurons as several reports support PTEN knockdown as a strategy to stimulate axonal regeneration after injury.
View Article and Find Full Text PDFJ Venom Anim Toxins Incl Trop Dis
January 2025
School of Health Santa Casa BH, Belo Horizonte, MG, Brazil.
Background: This study examines the impact of Phα1β, a spider peptide derived from the venom of , on the Kv11.1 potassium channel in HEK293 cells transfected with the human ERG potassium channel. Phα1β inhibits high-voltage calcium channels and acts as an antagonist of the TRPA1 receptor, both of which play crucial roles in pain transduction pathways.
View Article and Find Full Text PDFToxicon
January 2025
Venom and Biotherapeutics Molecules Lab., Medical Biotechnology Department, Biotechnology Research Center, Pasteur Institute of Iran, Tehran, Iran. Electronic address:
Scorpion envenomation, especially from Hemiscorpius lepturus, poses a significant health risk, leading to considerable morbidity and mortality. The venom's major toxin, which includes phospholipase D (PLD), is responsible for various systemic complications. In prior studies, we identified a native phospholipase D (PLD) toxin as a key lethal factor in the venom of H.
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