Topographical structure, nanomechanics and nanosurgical manipulation of biological supramolecular systems
Sziklai Dominik
Theoretical and Translational Medicine Division
Dr. Kellermayer Miklós
Semmelweis egyetem, Elméleti és Orvostudományi Központ, Hevesy György előadóterem
2026-01-14 14:00:00
Cellular and Molecular Physiology
Dr. Hunyady László
Dr. Kellermayer Miklós
Dr. Kiss Levente
Dr. Gáspári Zoltán
Dr. Szabó Dóra
Dr. Orbán Tamás
Dr. Bonyár Attila
My research used AFM and nanosurgery to investigate the structural and mechanical properties of the sarcomeric M-complex and associated proteins. The M-complex was confirmed to be a stable, titin-based hub, displaying elastic and plastic responses under mechanical manipulation. Nanosurgery revealed unfolding behaviors in titin filaments, deformation patterns, and rupture dynamics consistent with continuum mechanical models and force-loading theories. While myosin formed physiologically relevant structures, the thick-filament spatial organization deviated from the sarcomeric layout in vitro. Interestingly, titin and myosin did not co-assemble under standard conditions, but M-complexes interacted with thick filaments after relaxation, supporting a regulatory rather than scaffolding role for titin in filament organization.
AFM analysis of SARS-CoV-2 variants further demonstrated the technique’s utility in virology. Morphological differences between alpha, delta, and wild type virions were clearly resolved, with alpha being the most compact and wild type being the largest. Using a vesicle-plus-corona model, geometrical ratios suggested alpha and delta variants have more efficient host interaction surfaces. Bending rigidity estimates revealed variant-specific membrane stiffness, with the wild type being most rigid. These structural and mechanical distinctions may reflect functional adaptations influencing viral infectivity and stability.
