Search bioRxiv⌕ Search

bioRxiv · 10.64898/2026.10.14.759227

Differential Behavior of Uncleaved gp160 Human Immunodeficiency Virus Type 1 (HIV-1) Envelope (Env) Glycoproteins

Abstract

The envelope glycoprotein (Env) of human immunodeficiency virus type 1 (HIV-1) plays important roles in viral entry by coordinating host-cell receptor recognition and membrane fusion. Env is synthesized as a homotrimeric precursor, gp160, which is cleaved into gp120 and gp41 subunits. Although the cleaved form of Env is required for fusion, uncleaved Env remains plentiful on the surface of HIV-1-infected cells. Previous studies have suggested that uncleaved Env is conformationally more flexible than the cleaved form making its dynamics important for understanding the broader structural landscape of HIV-1 Env. In this study, we employed microsecond-long all-atom molecular dynamics (MD) simulations to characterize the dynamics of two structures of uncleaved HIV-1 Env that have been previously assigned to the same conformational state. Our results reveal differences in their conformational behavior, including differences in collective motions, FRET distributions, and trimer symmetry. These findings provide molecular-level insight into the structural plasticity of uncleaved HIV-1 Env and highlight that different structures within the same conformational state can exhibit distinct dynamic behavior.

Explore related subjects

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

Sauve, S., Moradi, M.. 2026-10-16. Differential Behavior of Uncleaved gp160 Human Immunodeficiency Virus Type 1 (HIV-1) Envelope (Env) Glycoproteins. https://doi.org/10.64898/2026.10.14.759227

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

KEEP EXPLORING

Related preprints

Cancers relax selection on charge at the mitochondrial complex I quinone cavity

Mitochondrial complex I translocates protons through hydrated channels whose connectivity and electrostatics are both defined by structure, but whether they are distinctly constrained is unknown. From a 2.39 cryo-EM structure modelling 2,945 ordered waters, we built the proton wire of the seven mtDNA-encoded ND subunits and scored all 40,166 missense substitutions on two near-orthogonal axes (r = 0.17): electrostatic shift at proton-loading sites, and topological disruption of the wire. Across 858 germline variant sites, loading sites (0.51) and cut vertices (0.67) are both depleted. In tumours only loading sites are enriched (1.42 TCGA, 1.67 PCAWG, 1.29 MSK-IMPACT), a 3.06-fold difference tested as a wire class tissue-type interaction (P = 3.6 10-). It survives adjustment for conservation, burial and coverage, and is concentrated in ND1 within 15 of the quinone cavity, not spread along the proton path. Selection separates charge from connectivity, without establishing a fitness benefit.

biophysics↗

Rugnux: from diffraction images to structure at synchrotrons and XFELs in one program

Rising data rates in macromolecular crystallography outpace multi-program pipelines on computing clusters. Rugnux, a single GPU-accelerated program, turns rotation or serial still diffraction images into merged data and an initial structure. At synchrotrons, results arrive seconds after the last image; on one workstation, 207 public datasets from 36 sources took a median of 15 s each, with deposition-quality. Serial XFEL data were processed faster than the collection rate, enabling real-time structure determination.

biophysics↗

Phase Separation of Intracellular Proteins Influences Synaptic Bistability

Synaptic bistability at the post synaptic density has been proposed to be the result of the nucleation and evaporation of receptor clusters. The exact biophysical mechanism underlying these inter-receptor attractions that can trigger nucleation remains to be elucidated. Emerging evidence demonstrates that numerous postsynaptic density submembrane proteins, that interact with various membrane receptors, can undergo phase separation, necessitating a revised conceptual model. By employing Langevin dynamics simulations of coarse-grained scaffold proteins and interacting membrane receptors, we study how phase transitions of scaffold proteins alter receptor clustering at the membrane. In our model, scaffold macromolecules can undergo phase separation and interact with receptor molecules at the model membranes. We observed that the presence of scaffold polymers across the membrane creates an attractive interaction between otherwise purely repulsive receptors. By systematically varying the number of receptors at the membrane, we dissected the coupling between receptor clustering and the phase behavior of scaffold macromolecules. We show that the propensity for receptor clustering is enhanced by the condensation of scaffold proteins. We then used two different scaffolds and systematically varied the interaction between them, to change the spatial organization of two condensed phases w.r.t. one another. Interestingly, we observed that receptor clustering can be reduced by co-phase separation of scaffold macromolecules, indicating the role of competing interactions in receptor clustering. Our work advances understanding of receptor-mediated signaling and phase separation, providing insights into cellular compartmentalization and biochemical regulation at the synapse.

biophysics↗