The wild-type -Phe*Pro- bond located at the N-terminus of the mature aspartic proteinase of HIV-1 was replaced by -Ile-Pro- or -Val-Pro-. By this means, processing at this cleavage junction was prevented and so, extended or precursor forms of HIV-proteinase were generated. These constructs were expressed in Escherichia coli, purified therefrom, and their specificity, activity at different pH values and susceptibility to the potent inhibitor, Ro31-8959, was assessed. A hitherto unobserved cleavage junction (at approximately Ala-Phe*Leu-Gln approximately) in the frame-shift region of the gag-pol viral genome was identified and confirmed by demonstrating cleavage of a synthetic peptide corresponding to this region. The implications for viral replication of self-processing at neural pH by proteinase whilst still present (in a precursor form) as a component of the polyprotein are considered; such reactions, however, are still blocked even at pH values as high as 8.0 by Ro31-8959.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1016/0014-5793(92)81524-p | DOI Listing |
Cell Mol Biol Lett
January 2025
Enzymology and Metabolism Group, Luxembourg Centre for Systems Biomedicine, University of Luxembourg, L-4367, Belvaux, Luxembourg.
Background: Metabolism is error prone. For instance, the reduced forms of the central metabolic cofactors nicotinamide adenine dinucleotide (NADH) and nicotinamide adenine dinucleotide phosphate (NADPH), can be converted into redox-inactive products, NADHX and NADPHX, through enzymatically catalyzed or spontaneous hydration. The metabolite repair enzymes NAXD and NAXE convert these damaged compounds back to the functional NAD(P)H cofactors.
View Article and Find Full Text PDFEnviron Int
January 2025
Département de Chimie, Université de Montréal, Montreal, QC, Canada. Electronic address:
This study investigated the occurrence of perfluoroalkyl and polyfluoroalkyl substances (PFAS), including anionic, cationic, and zwitterionic compounds, in drinking water. Between 2021-2023, an expanded list of 76 target PFAS was screened in tap water samples mainly from Canada, but also including tap water samples from the Eastern United States, Mexico, South America (Argentina), the Caribbean (Dominican Republic, Cuba), Africa (Algeria, Cameroon, Central African Republic, Morocco, Rwanda, Tunisia), Europe (France, Greece, Italy, Spain, and the United Kingdom) and Asia (Japan, Vietnam, Iran, and Türkiye). An additional ∼ 200 suspect-target PFAS were screened using high-resolution Orbitrap mass spectrometry.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
January 2025
Georgia State University, Chemistry, 50 Decatur ST SE, 30303, Atlanta, UNITED STATES OF AMERICA.
Poly-N-acetyllactosamine (poly-LacNAc) is ubiquitously expressed on cell surface glycoconjugates, serving as the backbone of complex glycans and an extended scaffold that presents diverse glycan epitopes. The branching of poly-LacNAc, where internal galactose (Gal) residues have β1-6 linked N-acetylglucosamine (GlcNAc) attached, forms the blood group I-antigen, which is closely associated with various physiological and pathological processes including cancer progression. However, the underlying mechanisms remain unclear as many of the I-antigen sequences are undefined and inaccessible.
View Article and Find Full Text PDFAdv Sci (Weinh)
January 2025
State Key Laboratory for Modification of Chemical Fibers and Polymer Materials & College of Materials Science and Engineering, Donghua University, Shanghai, 201620, China.
High-performance bulk graphite (HPBG) that simultaneously integrates superior electrical conductivity and excellent strength is in high demand, yet it remains critical and challenging. Herein a novel approach is introduced utilizing MOF-derived nanoporous metal/carbon composites as precursors to circumvent this traditional trade-off. The resulting bulk graphite, composed of densely packed multilayered graphene sheets functionalized with diverse cobalt forms (nanoparticles, single atoms, and clusters), exhibits unprecedented electrical conductivity in all directions (in-plane: 7311 S cm⁻¹, out-of-plane: 5541 S cm⁻¹) and excellent mechanical strength (flexural: 101.
View Article and Find Full Text PDFAlzheimers Dement
December 2024
Department of Bioengineering, University of California, San Diego, La Jolla, CA, USA.
Background: Early-onset Alzheimer's disease (EOAD) is a complex disease that occurs at an early age at onset (AAO) before 65 years, constituting 5-6% of all AD cases and remains poorly understood. Patient-derived induced pluripotent stem cells (iPSCs) have been used to model different forms of EOAD that display heterogeneous disease mechanisms.
Method: We examined iPSC-derived neurons from both familial EOAD harboring mutations in PSEN1 , PSEN2, and APP and non-familial EOAD patients at an early AAO.
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!