Search bioRxiv⌕ Search

bioRxiv · 10.1101/2021.10.29.466510

Solvation dynamics-powered structure and function of multi-molecular cellular systems exemplified by non-equilibrium cereblon-degrader-CK1α ternary complex formation

Abstract

Cellular functions are executed via a form of analog computing that is based on the switchable covalent and non-covalent states of multi-molecular fluxes (i.e., time-dependent species/state concentrations) operating in the non-linear dynamics regime. We and others have proposed that the non-covalent states and state transitions of aqueous fluxes are powered principally by the storage and release of potential energy to/from the anisotropic H-bond network of solvating water (which we refer to as the "solvation field"), which is a key tenet of a first principles theory on cellular structure and function (called Biodynamics) that we outlined previously. This energy is reflected in water occupancy as a function of solute surface position, which can be probed computationally using WATMD software. In our previous work, we used this approach to deduce the structural dynamics of the COVID main protease, including substrate binding-induced enzyme activation and dimerization, and product release-induced dimer dissociation. Here, we examine: 1) The general relationships between surface composition/topology and solvation field properties for both high and low molecular weight (HMW and LMW) solutes. 2) The general means by which structural dynamics are powered by solvation free energy, which we exemplify via binding between the E3 ligase CUL4A/RBX1/DDB1/CRBN, LMW degraders, and substrates. We propose that degraders organize the substrate binding surface of cereblon toward complementarity with native and neo substrates, thereby speeding the association rate constant and incrementally slowing the dissociation rate constant. 3) Structure-activity relationships (SAR) based on complementarity between the solvation fields of cognate protein-ligand partners exemplified via LMW degraders.

Explore related subjects

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

Wan, H., Aravamuthan, V., Williams, S., Wartchow, C., Duca, J., Pearlstein, R. A.. 2021-10-31. Solvation dynamics-powered structure and function of multi-molecular cellular systems exemplified by non-equilibrium cereblon-degrader-CK1α ternary complex formation. https://doi.org/10.1101/2021.10.29.466510

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

KEEP EXPLORING

Related preprints

Lipid-ASO therapeutics exhibit differential tissue targeted delivery upon systemic or local CNS administration

Antisense oligonucleotides (ASOs) are a powerful therapeutic modality, but their full potential is hindered by pharmacokinetic properties that affect tissue and cellular delivery. Lipid conjugation is increasingly used to modulate ASO's biodistribution and promote extrahepatic activity, yet lipid dependent effects on in vivo functional delivery, particularly in the central nervous system (CNS), remain less explored. Here, we performed a side by side in vivo comparison of cholesterol, palmitic acid (C16:0), docosanoic acid (C22:0), and eicosapentaenoic acid (C20:5) conjugated to a fully phosphorothioated 3 10 3 LNA gapmer ASO targeting the Malat1 long non coding RNA. Lipid-ASO conjugates were administered systemically or locally in the brain of mice and evaluated for tissue level and cellular level distribution by imaging, qPCR and single-cell RNA sequencing, simultaneously annotating cell origin and global transcriptional changes within the cell. Following systemic administration in mice, lipid conjugation improved overall multi organ efficacy compared to unconjugated ASO, but with pronounced tissue specific differences. Single cell sequencing of liver and heart transcriptomes revealed lipid dependent cellular uptake patterns and transcriptional responses distinct from administration of unconjugated ASO. After intracerebroventricular administration, selected fatty acid conjugates enhanced silencing in deep brain regions such as the striatum, whereas cholesterol conjugation impaired functional delivery despite increased CNS retention. Light-sheet microscopy showed restricted parenchymal penetration of cholesterol ASOs compared with broader but heterogeneous distribution of palmitic acid conjugate. Together, these findings demonstrate that lipid identity critically determines ASO efficacy, productive cellular uptake, and regional CNS engagement, emphasizing the need for context specific lipid design in ASO therapeutic development.

pharmacology and toxicology↗

Novel Dissymmetric Ionizable Lipid-Assembled Lipid Nanoparticles for Delivery of Ferroptosis-Related siRNA in Diabetic Treatment

Small interfering RNA (siRNA) enables precise post-transcriptional gene silencing for refractory diseases, yet its clinical translation remains limited by the lack of safe and efficient delivery vectors. Inspired by the dissymmetric alkyl chain architecture of natural membrane phospholipids, we designed and synthesized 34 novel ionizable lipids with dissymmetric hydrophobic tails and formulated them into lipid nanoparticles (LNPs). Through systematic physicochemical and biological assessments, we established clear structure-activity relationships and identified two lead LNPs (O14-LNP, H18a-LNP) with superior endosomal escape capacity, enhanced in vivo gene silencing potency, and favorable biosafety relative to the clinical benchmark MC3-LNP. In both streptozotocin-induced and spontaneous db/db type 2 diabetes (T2D) mouse models, lead LNPs delivering ferroptosis-related siRNAs effectively ameliorated glucose and lipid metabolic disorders, restored islet function, and alleviated hepatic steatosis. This study not only lays a theoretical foundation for the rational design of novel ionizable lipids, but also validates the therapeutic potential of siRNA therapy targeting ferroptosis, providing a versatile delivery platform and targeted therapeutic strategy for the treatment of T2D.

pharmacology and toxicology↗

Inhibition of integrin alpha V (CD51) reduces inflammation and transition to heart failure following pressure overload

BackgroundIntegrins are surface receptors that bind to extracellular matrix ligands and regulate cellular function through mechanical stress-initiated signal transduction. Integrin alpha V (or CD51) is implicated in myocardial fibrosis and anti-CD51 therapy improves cardiac function and cardiac fibrotic remodeling following myocardial infarction. However, their contribution in non-ischemic pressure-overload induced heart failure has not been established. MethodsWe implanted male C57BL/6J wild-type mice with osmotic minipumps containing a combination of AngII (1.44mg/kg/day) and the 1 adrenergic agonist Phenylephrine (PE)(50mg/kg/day) to induce hypertrophic heart failure. Treatment with AngII alone was used as a model of compensated cardiac hypertrophy. Mice treated with PE or saline were used as controls. Animals were treated with daily intraperitoneal injections of the anti-CD51 molecule cilengitide or vehicle. Cardiac echography, flow cytometry, histological, and protein analyses were used to study the development of fibrosis and cardiac adverse remodeling. ResultsMice treated with the combination of AngII and PE showed maladaptive cardiac hypertrophy associated with a fibrotic remodeling and a rapid transition to heart failure. CD51 protein expression and CD51+ cell number were increased in the myocardium of these animals. In contrast, mice treated with AngII alone exhibited compensated cardiac hypertrophy with low levels of fibrosis, no signs of congestive heart failure, and no changes in cardiac CD51 expression as well as CD51+ cell number. Anti-CD51 therapy in mice receiving AngII + PE significantly reduced the transition to heart failure and the development of cardiac fibrosis. Anti-CD51 therapy notably reduced the recruitment of monocyte-derived pro-inflammatory CCR2+ cardiac macrophages, which also showed a high expression of CD51 at their surface. Macrophages sense matrix stiffness and activate a pro-inflammatory response to stiffer substrates, a response that was blunted by anti-CD51 therapy. ConclusionAnti-CD51 therapy reduces the transition to heart failure in response to pressure overload and modulates the pro-inflammatory and deleterious action of CD51+ myeloid cells. We identified CD51 inhibition as a novel therapeutic strategy for reducing the progression of non-ischemic and pressure-dependent heart failure. Clinical perspectivesWhat is new? - We observed a pathologic role of the integrin alpha V in causing a maladaptive response to pressure overload. - A specific pharmacological inhibition of integrin alpha V reduced the transition to heart failure through modulation of the pro-inflammatory and deleterious action of integrin alpha V+ CCR2+ cardiac macrophages. What are the clinical implications? - This study adds to the growing interest in targeting integrins in cardiac disorders by showing a novel immunomodulatory effect. - Integrin alpha V inhibition should be considered as a novel therapeutic strategy for reducing non-ischemic and pressure-dependent heart failure.

pharmacology and toxicology↗