Search bioRxiv⌕ Search

bioRxiv · 10.1101/2023.08.25.554876

Computational Drug Design of Novel Agonists of the μ-Opioid Receptor to Inhibit Pain Signaling

Abstract

Opioids such as Morphine, Codeine, Hydrocodone, and Oxycodone target the -opioid receptor, a G-protein-coupled receptor (GPCR), blocking the transmission of nociceptive signals. In this study, four opioids were analyzed for ADMET properties and molecular interactions with a GPCR crystal structure (PDB ID: 8EF6). This aided in the computational design of two novel drug candidates with improved docking scores and ADMET properties when compared to Hydrocodone. Homology analysis indicated that a Mus musculus (house mouse) animal model could be used in the preclinical studies of these drug candidates in the development of safer and more effective opioid drugs for pain management with reduced side effects.

Explore related subjects

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

Daoud, N., Mateos, D. L., Riley, M., Siegel, J. B.. 2023-08-26. Computational Drug Design of Novel Agonists of the μ-Opioid Receptor to Inhibit Pain Signaling. https://doi.org/10.1101/2023.08.25.554876

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related preprints

The C-terminus of the KREH1 helicase is important for RNA binding and association with mitochondrial RNA editing complexes in T. brucei

Mitochondrial pre-mRNA editing in kinetoplastids, a clade that includes human-infective parasitic protists such as Trypanosoma and Leishmania, is required to produce translatable, functional gene products from otherwise nonfunctional mitochondrial precursor transcripts of essential respiratory chain complex subunits. RNA editing is a template-guided process in which cognate guide RNAs (gRNAs) anneal to specific sites at the pre-mRNA and direct the complementary insertion and/or deletion of uridines. Large multi-modular complexes - like the RNA-Editing Substrate-binding Complex (RESC) and the RNA-Editing Catalytic Complexes (RECC) - organize and catalyze RNA editing, respectively. Within these assemblies, Kinetoplast RNA Editing Helicases (KREHs) play an important role in ribonucleoprotein complex remodeling, particularly in pan-editing, when transcripts are extensively modified throughout their length by multiple gRNAs. However, the mechanisms by which KREH RNA helicases facilitate pan-editing, and their specific roles in this process, remain unclear. Here, we define the molecular properties of the Trypanosoma brucei DEAD-box RNA editing helicase KREH1. Cellular co-proteome analyses reveal that KREH1 interacts with subunits of the RESC complex and biochemical experiments show that KREH1 is an RNA-dependent ATPase that unwinds double-stranded RNA substrates. We show that the flexible C-terminus of KREH1 is important for RNA binding and, consequently, for enzymatic activity in vitro and interactions with the RESC complex in vivo. Overall, our experiments refine the role of KREH1 in the pan-editing process and establish its utility as a molecular tool for investigating higher-order RNA editing complexes in the cellular context.

molecular biology↗

Structural basis of nucleosome remodeling by archaeal RNA polymerase during transcription elongation

Transcription occurs in the context of histone-based chromatin in eukaryotes and most archaea. The archaeal RNA polymerase and histones are ancestral to their eukaryotic counterparts, yet how RNA polymerase traverses histone-bound DNA in archaea remains poorly understood. Here, we reconstitute a nucleosome-associated transcription elongation complex (TEC) from Pyrococcus furiosus and capture its structure across multiple elongation states by cryo-electron microscopy (cryo-EM). High-resolution structures reveal that the RNA polymerase engages a three-dimer HPfB nucleosome positioned downstream. We identify direct physical interactions between HPfB and Rpo1N RNA polymerase subunit, establishing a defined polymerase-histone interface during transcription. Structural comparisons across defined elongation states demonstrate that RNA polymerase first translocates on DNA using the proximal histone dimer as an anchor, followed by destabilisation of the distal dimer. The DNA exiting the nucleosome is partially unwrapped and is redirected traversing the Rpo4/7 stalk. At extended transcript lengths nucleosome organisation is lost, indicating that transcription elongation ultimately disrupts histone-DNA interactions. This work provides the first structural insight into transcription through chromatin in archaea, revealing a mechanism in which the archaeal RNA polymerase actively remodels nucleosomes via DNA redirection and histone displacement, aided by direct polymerase-histone contacts.

molecular biology↗

Structural mechanism of Gasdermin E-mediated mtDNA release from apoptotic mitochondria

During apoptosis, the permeabilization of the mitochondrial inner membrane (MIM) through still-unclear mechanisms releases mtDNA into the cytosol, triggering the inflammatory cGAS/STING pathway under low caspase activity. Here, we report that, in apoptosis, the active form of the pore-forming protein Gasdermin E (GSDME-N) damages mitochondria before plasma membrane disruption. We visualize GSDME-N pore-like nano-assemblies in the MIM of apoptotic cells and of isolated mitochondria, which we bridge with the cryo-EM structure of the GSDME-N pore in mitochondria-like membranes. Deep membrane insertion of the anchor domain, which acts as a determinant of GSDME-N cardiolipin binding preferences, supports a role in pore formation. Notably, GSDME depletion results in a reduction in cristae swelling, MIM extrusion and mtDNA release during apoptosis. Subsequently, this decreases STING activation and inflammatory responses under caspase inhibition. Our findings reveal that GSDME mediates MIM permeabilization and mtDNA release during apoptosis and define the mechanism of GSDME-mediated membrane damage.

molecular biology↗