The dissociation constants of the complexes of RNA-ligase with acceptors, donors and the adenylylated donor A(5')ppAp have been determined on the basis of the inhibition of ATP-pyrophosphate exchange reaction. The dissociation constants of the complexes of the enzyme with "poor" acceptors (oligouridilates) have been shown to be slightly different from those with "good" acceptors (oligoadenylates). The dependence of the reaction velocity of the formation of ligation products on the concentration of acceptors (pA)4, (pU)4 and the adenylylated donor A(5)ppAp has been studied. On the basis of the data obtained the conclusion about the random addition mechanism has been drawn. The reaction takes place in the steady-state conditions in the case of (pA)4 and in the equilibrium conditions--in the case of (pU)4.
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Chemistry
January 2025
RIKEN: Rikagaku Kenkyujo, Cluster for Pioneering Research, Hirosawa 2-1, 351-0198, Wako, JAPAN.
Protein immobilization technology is important in medical and industrial applications. We previously reported all-in-one in vitro selection, wherein a collagen-binding vascular endothelial growth factor (CB-VEGF) was identified from a fusion library of random and VEGF sequences. However, its interaction chemistry is mainly limited to the interaction established by the 20 canonical amino acids.
View Article and Find Full Text PDFAnal Chim Acta
January 2025
Department of Chemistry, University of Nebraska-Lincoln, Lincoln, NE, USA. Electronic address:
Background: DJ-1 is a protein whose mutation causes rare heritable forms of Parkinson's disease (PD) and is of interest as a target for treating PD and other disorders. This work used high performance affinity microcolumns to screen and examine the binding of small molecules to DJ-1, as could be used to develop new therapeutics or to study the role of DJ-1 in PD. Non-covalent entrapment was used to place microgram quantities of DJ-1 in an unmodified form within microcolumns, which were then used in multiple studies to analyze binding by model compounds and possible drug candidates to DJ-1.
View Article and Find Full Text PDFJ Hazard Mater
January 2025
CAS Key Laboratory of Urban Pollutant Conversion, Department of Environmental Science and Engineering, University of Science and Technology of China, Hefei 230026, China.
The introduction of structural defects can improve the charge separation efficiency of metal-organic frameworks (MOFs)-based photocatalysts, which however come with suboptimal decontamination performance, due to steric hindrance and limited binding capacity of the involved modulators. In this work, hydroxyl group capturing the advantages of both worlds was utilized as new modulator to improve the photocatalytic performance of Fe-based defective MOFs. Benefited from its low steric effect and strong coordination bonding capability, hydroxyl-induced defects in Fe-MOF contributed to a nearly 8-fold increase of rate constant for the photocatalytic removal of hexavalent chromium (Cr(VI)) compared to that of pristine one, which also exceeded the defective one induced by acetic acid as modulator.
View Article and Find Full Text PDFBackground: With the approval of several anti-amyloid antibodies and a robust pipeline of new amyloid-based therapies, attention turns towards questions related to real-world clinical practice. Here we explore the impact of several biological pathways on the amyloid biomarker response of AD patients using a Quantitative Systems Pharmacology (QSP) approach with the ultimate objective to find measurable biomarkers for responder identification.
Method: Using a well-validated QSP biophysically realistic model of amyloid aggregation, we performed sensitivity analysis to identify key drivers of amyloid biomarkers both in a longitudinal observational context and after treatment with specific amyloid antibodies.
Alzheimers Dement
December 2024
All India Institute of Medical Sciences, AIIMS, New Delhi, Delhi, India.
Background: Alzheimer's disease (AD) is a progressive brain disorder which leads to gradual decline in memory, thinking, behaviour and social skills. The current scenario for drug development is based on neuro-inflammation and oxidative stress. Amyloid-β (Aβ) deposition, a major hallmark of the disease activates microglia leading to neuro-inflammation and neuro-degeneration induced by activation of COX-2 via NFkB p50 in glioblastoma cells.
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