Hydroxyurea is the only FDA approved treatment of sickle cell disease. It is believed that the primary mechanism of action is associated with the pharmacological elevation of nitric oxide in the blood; however, the exact details of this are still unclear. In the current work, we investigate the atomic level details of this process using a combination of flexible-ligand/flexible-receptor virtual screening coupled with energetic analysis that decomposes interaction energies. Utilizing these methods, we were able to elucidate the previously unknown substrate binding modes of a series of hydroxyurea analogs to hemoglobin and the concomitant structural changes of the enzyme. We identify a backbone carbonyl that forms a hydrogen bond with bound substrates. Our results are consistent with kinetic and electron paramagnetic resonance (EPR) measurements of hydroxyurea-hemoglobin reactions, and a full mechanism is proposed that offers new insights into possibly improving substrate binding and/or reactivity.
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http://dx.doi.org/10.1021/ci300035c | DOI Listing |
Free Radic Biol Med
January 2025
University of Colorado, Anschutz Medical Campus School of Medicine| Translational research laboratory of Red Blood Cell Diseases and Hypoxia related illnesses| Cardiovascular Pulmonary Research (CVP) group, Pediatrics. Electronic address:
Lung tissue from human patients and murine models of sickle cell disease pulmonary hypertension (SCD-PH) show perivascular regions with excessive iron accumulation. The iron accumulation arises from chronic hemolysis and extravasation of hemoglobin (Hb) into the lung adventitial spaces, where it is linked to nitric oxide depletion, oxidative stress, inflammation, and tissue hypoxia, which collectively drive SCD-PH. Here, we tested the hypothesis that intrapulmonary delivery of hemopexin (Hpx) to the deep lung is effective at scavenging heme-iron and attenuating the progression of SCD-PH.
View Article and Find Full Text PDFTuberculosis (Edinb)
January 2025
Infectious Bacterial Diseases Research Unit, National Animal Disease Center, Agricultural Research Service, United States Department of Agriculture, Ames, Iowa, USA.
Bovine tuberculosis is mainly caused by Mycobacterium bovis. Bacillus Calmette-Guérin (BCG) is an attenuated strain of M. bovis which provides variable disease protection.
View Article and Find Full Text PDFJ Cereb Blood Flow Metab
January 2025
Neurovascular Research Laboratory, Faculty of Life Sciences and Education, University of South Wales, Pontypridd, UK.
To what extent sildenafil, a selective inhibitor of the type-5 phosphodiesterase modulates systemic redox status and cerebrovascular function during acute exposure to hypoxia remains unknown. To address this, 12 healthy males (aged 24 ± 3 y) participated in a randomized, placebo-controlled crossover study involving exposure to both normoxia and acute (60 min) hypoxia (Fi = 0.14), followed by oral administration of 50 mg sildenafil and placebo (double-blinded).
View Article and Find Full Text PDFSemin Immunopathol
January 2025
Institute for Clinical Chemistry and Laboratory Medicine, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Fetscherstrasse 74, 01307, Dresden, Germany.
Metabolic flexibility is key for the function of myeloid cells. Arginine metabolism is integral to the regulation of myeloid cell responses. Nitric oxide (NO) production from arginine is vital for the antimicrobial and pro-inflammatory responses.
View Article and Find Full Text PDFInt J Biol Macromol
January 2025
Research Department of Chemistry, Nehru Memorial College (Affiliated Bharathidasan University), Puthanampatti, Tamilnadu 621007, India. Electronic address:
This study successfully synthesised and characterised composites combining chitosan (CH), carboxymethyl cellulose (CMC), and various flavonoids (Fla). This innovative approach demonstrates the potential for developing functional materials with antioxidant and food preservation properties. The composites CH-Fla-CMC (1-5) was characterised using advanced techniques such as FT-IR, UV-Vis, XRD, SEM, TEM, and TGA, providing robust data on their structural, morphological, and thermal properties.
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