The long-range communication between the two exosites of human α-thrombin (thrombin) tightly modulates the protein-effector interactions. Duplex/quadruplex aptamers represent an emerging class of very effective binders of thrombin. Among them, NU172 and HD22 aptamers are at the forefront of exosite I and II recognition, respectively. The present study investigates the simultaneous binding of these two aptamers by combining a structural and dynamics approach. The crystal structure of the ternary complex formed by the thrombin with NU172 and HD22_27mer provides a detailed view of the simultaneous binding of these aptamers to the protein, inspiring the design of novel bivalent thrombin inhibitors. The crystal structure represents the starting model for molecular dynamics studies, which point out the cooperation between the binding at the two exosites. In particular, the binding of an aptamer to its exosite reduces the intrinsic flexibility of the other exosite, that preferentially assumes conformations similar to those observed in the bound state, suggesting a predisposition to interact with the other aptamer. This behaviour is reflected in a significant increase of the anticoagulant activity of NU172 when the inactive HD22_27mer is bound to exosite II, providing a clear evidence of the synergic action of the two aptamers.
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http://dx.doi.org/10.1016/j.ijbiomac.2021.04.076 | DOI Listing |
Int J Mol Sci
December 2024
Department of Physicochemical Drug Analysis, Jagiellonian University Medical College, Medyczna Str. 9, 30-688 Kraków, Poland.
Alzheimer's disease, the most common form of dementia, is characterized by the deposition of amyloid plaques and neurofibrillary tangles in the brain, leading to the loss of neurons and a decline in a person's memory and cognitive function. As a multifactorial disease, Alzheimer's involves multiple pathogenic mechanisms, making its treatment particularly challenging. Current drugs approved for the treatment of Alzheimer's disease only alleviate symptoms but cannot stop the progression.
View Article and Find Full Text PDFMolecules
December 2024
Department of Medicinal Chemistry, School of Pharmacy, Fudan University, 826 Zhangheng Road, Shanghai 201203, China.
As an appealing approach for discovering novel leads, the key advantage of de novo drug design lies in its ability to explore a much broader dimension of chemical space, without being confined to the knowledge of existing compounds. So far, many generative models have been described in the literature, which have completely redefined the concept of de novo drug design. However, many of them lack practical value for real-world drug discovery.
View Article and Find Full Text PDFNat Commun
January 2025
Institute of Bioanalytical Chemistry, Faculty of Chemistry and Mineralogy, Universität Leipzig, Leipzig, Germany.
The proline-rich antimicrobial designer peptide Api137 inhibits protein expression in bacteria by binding simultaneously to the ribosomal polypeptide exit tunnel and the release factor (RF), depleting the cellular RF pool and leading to ribosomal arrest at stop codons. This study investigates the additional effect of Api137 on the assembly of ribosomes using an Escherichia coli reporter strain expressing one ribosomal protein per 30S and 50S subunit tagged with mCherry and EGFP, respectively. Separation of cellular extracts derived from cells exposed to Api137 in a sucrose gradient reveals elevated levels of partially assembled and not fully matured precursors of the 50S subunit (pre-50S).
View Article and Find Full Text PDFTalanta
January 2025
Department of Chemistry, Alfaisal University, Al Zahrawi Street, Al Maather, Al Takhassusi Road, Riyadh, 11533, Saudi Arabia. Electronic address:
Envenomation accidents are usually diagnosed at the hospital through signs and symptoms assessment such as short breath, dizziness and vomiting, numbness, swilling, bruising, or bleeding around the affected site. However, this traditional method provides inaccurate diagnosis given the interface between snakebites and scorpion stings symptoms. Therefore, early determination of bites/stings source would help healthcare professionals select the suitable treatment for patients, thus improving envenomation management.
View Article and Find Full Text PDFProc Natl Acad Sci U S A
January 2025
Institute of Science and Technology Austria, AT-3400 Klosterneuburg, Austria.
Biophysical constraints limit the specificity with which transcription factors (TFs) can target regulatory DNA. While individual nontarget binding events may be low affinity, the sheer number of such interactions could present a challenge for gene regulation by degrading its precision or possibly leading to an erroneous induction state. Chromatin can prevent nontarget binding by rendering DNA physically inaccessible to TFs, at the cost of energy-consuming remodeling orchestrated by pioneer factors (PFs).
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