Date: 12 May 2026

Time: 15:00 CET

Registration

Abstract

Short peptides have been instrumental as models for more complex systems. Studying short peptides, we have gained understanding of fundamental folding events like alpha helix nucleation or hairpin folding, and in the determination of the microscopic origin of internal friction. Short peptides are also challenging tests for the calibration of modern force fields, and hence have been extensively used in recent optimization efforts. In my talk I will focus on our recent work on phase separation in our laboratory. Using peptide models, we test the hypothesis that phase separation is an emergent property determined by composition, even in the absence of a polypeptide chain, multivalency and patterning effects. For this, we use atomistic molecular dynamics (MD) simulations of saturated solutions of individual amino acids and mixtures thereof in stoichiometries comparable to those of phase-separating low com-plexity domains. Additionally, we disentangle the hierarchy of interaction strength between the two most dominant types of aromatic and positively charged residues in condensates. Our results are broadly consistent with trends observed in experiments and in atomistic simulations of full-length IDPs and reconcile findings from decades of work in physical chemistry and protein biophysics.

Presenters

David de Sancho

David is a research professor at the University of the Basque Country (UPV/EHU) and the Donostia International Physics Center, where he received tenure in 2023 following a Ramón y Cajal fellowship. His work is rooted in computational protein biophysics, a field he’s explored for 20 years by using molecular simulations to map out protein energy landscapes and modulate their functions. His journey started with a PhD focused on genetic algorithms and coarse-grained models, followed by postdoctoral stays at the Spanish Research Council and the University of Cambridge. Some of his key research achievements in this period were the determination of alpha-helix folding rates, resolving the molecular cause of internal friction and identifying gas tunnels in enzymes. After returning to Spain via Ikerbasque and CIC nanoGUNE, he now co-leads the BIOKT group, where they dive into the complex world of intrinsically disordered proteins using a mix of computational chemistry and molecular dynamics.

LinkedIn: @david-de-sancho-71b06150

Bluesky: @daviddesancho.bsky.social