Biophysical Society Thematic Meeting | Riga 2026

Active and Responsive Soft Matter: From Biological to Engineered Systems

Poster Abstracts

17-POS Board 17 AUTOMATED STEERED MOLECULAR DYNAMICS PLATFORM FOR CHARACTERIZING TALIN ROD DOMAIN MECHANOSENSING Alexandra Van Kley 1 ; Armen Nalian; 1 Stephen F Austin State University UT system, Biology, Nacogdoches, TX, USA Mechanosensitive proteins such as talin regulate force-dependent signaling by exposing cryptic binding sites under mechanical load; however, systematic atomistic characterization of their unfolding behavior remains limited. The objective of this study is to develop and apply an automated framework for analyzing force-induced protein unfolding and identifying functionally relevant intermediate states. Here, we present SciFlow, an automated platform for constant velocity steered molecular dynamics (SMD) that integrates structure preparation, replica-based NAMD3 simulations, and force–extension analysis with correlated structural metrics. We validated SciFlow using the third fibronectin type III domain of tenascin (TNfn3; PDB: 1TEN), reproducing established unfolding behavior with a peak force of 1001 ± 64 pN at 5 Å/ns (N = 3). Analysis of native-contact loss revealed two distinct unfolding pathways: a dominant sequential C-terminal strand peeling mechanism and a less frequent catastrophic rupture via a partially folded intermediate, consistent with prior studies. We then applied SciFlow to the talin rod domain R3 (PDB: 2L7A), a key mechanosensitive module that regulates vinculin binding. Comparison of wild-type and the mechanically stabilized IVVI mutant (T809I/T833V/T867V/T901I) revealed markedly different force–extension profiles. The IVVI mutant exhibited a sharp unfolding transition at ~805 pN with multiple sub-peaks, indicating altered mechanical stability and intermediate-state populations relative to wild-type. A comprehensive SMD survey of all talin rod domains (R1–R12) under a unified protocol is ongoing. These results demonstrate that force-resolved unfolding trajectories can be used to identify recurrent, structurally defined intermediate states that are both functionally relevant and amenable to selective ligand targeting, establishing a foundation for mechanopharmacology approaches to modulate focal adhesion signaling.

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