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A chromatographic method using HPAEC-PAD was developed to accurately quantify the major oligosaccharides derived from lichenase degradation of barley β-glucan. This method was further used to follow β-glucosidase degradation and product formation as progress curves. This approach allowed us to compare the kinetic characteristics of β-glucosidase on each exclusive oligosaccharide substrate and their mixtures. Our results show that when determining the kinetic parameters of exohydrolases on oligosaccharides following the progress curve for the substrates is necessary since calculations based only on released monosaccharide products may lead to an error. The catalytic activity of almond β-glucosidase on laminaribiose (G3G) was approximately half that measured against cellobiose (3.15 S(-1)). The enzyme had 12 times and 560 times less catalytic activity on 3-O-β-cellobiosyl-D-glucose (G4G3G) and on 3-O-β-cellotriosyl-d-glucose (G4G4G3G) respectively than on G3G. Our approach offers a useful tool for the determination of the kinetics of enzymatic or chemical modification of various carbohydrate substrates.
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http://dx.doi.org/10.1016/j.carres.2012.06.008 | DOI Listing |
PLoS Comput Biol
September 2025
University of Chinese Academy of Sciences, Beijing, China.
The divergence in folding pathways between RNA co-transcriptional folding (CTF) and free folding (FF) is crucial for understanding dynamic functional regulation of RNAs. Here, we developed a simplified all-atom molecular dynamics framework to systematically compare the folding kinetics of an RNA hairpin (PDB:1ZIH) under CTF and FF conditions. By analyzing over 800 microseconds of simulated trajectory, we found that despite convergence to identical native conformations across CTF simulations (with varied transcription rates) and FF simulations, they exhibit distinct preferences for the folding pathways defined by the order of base-pair formation.
View Article and Find Full Text PDFInvest Ophthalmol Vis Sci
September 2025
Department of Ophthalmology, Dean McGee Eye Institute, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, United States.
Purpose: Adeno-associated viruses (AAVs) have become the preferred vector for gene therapy in ophthalmology. However, requirements for specific cell surface receptors limit AAV-mediated retinal cell transduction efficiency. This led to the need to engineer novel AAV vectors for widespread retinal transduction and transgene expression.
View Article and Find Full Text PDFNitric Oxide
September 2025
Department of Physics, Wake Forest University, Winston-Salem, NC, 27109, USA; Translational Science Center, Wake Forest University, Winston-Salem, NC, 27109, USA. Electronic address:
We recently demonstrated a rapid reaction between labile ferric heme and nitric oxide (NO) in the presence of reduced glutathione (GSH) or other small thiols in a process called thiol-catalyzed reductive nitrosylation, yielding a novel signaling molecule, labile nitrosyl ferrous heme (NO-ferroheme), which we and others have shown can regulate vasodilation and platelet homeostasis. Red blood cells (RBCs) contain high concentrations of GSH, and NO can be generated in the RBC via nitrite reduction and/or RBC endothelial nitric oxide synthase (eNOS) so that NO-ferroheme could, in principle, be formed in the RBC. NO-ferroheme may also form in other cells and compartments, including in plasma, where another small and reactive thiol species, hydrogen sulfide (HS/HS), is also present and may catalyze NO-ferroheme formation akin to GSH.
View Article and Find Full Text PDFDermatology
September 2025
Department of Clinical Pharmacology and Toxicology, University of Geneva, Geneva, Switzerland.
Introduction: Non-transient erythema (NTE) is a major feature of rosacea, but its clinical evaluation is subject to human investigator variability. The angiopoietin-TIE2 receptor tyrosine kinase pathway plays a key role in regulating vascular homeostasis, but was previously overlooked as a target for rosacea therapy. Angiopausin® is a patented plant-based ingredient identified through a molecular phytotherapy screening program as a positive inducer of the angiopoietin-TIE2 pathway, which is the "gatekeeper of vascular quiescence.
View Article and Find Full Text PDFThe non-polio enteroviruses enterovirus-D68 (EV-D68) and enterovirus-A71 (EV-A71) are highly prevalent and considered pathogens of increasing health concern. While most enterovirus infections are mild and self-limiting, severe complications ranging from meningitis, encephalitis, to acute flaccid paralysis can occur, especially in children and immunocompromised patients. Despite the global burden of neurological complications caused by EV-D68 and EV-A71, the underlying neuropathogenesis remains poorly understood.
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