Thermomechanical effects in decohesion and damage of double-stranded biological systems

Dr Luca Bellino (Politecnico di Bari)

Thursday 2nd March, 2023 14:00-15:00 Maths 311B / (ID: 865 8698 7877)

Abstract

Biological materials have outstanding thermomechanical properties often unattained by artificial materials, and their remarkable macroscopic properties typically results from a unique multiscale hierarchical structure. At the molecular scale, these systems are characterized mainly by polypeptide molecules arranged in different structures such as double-stranded arrays, and their correct functioning is of paramount importance to avoid diseases and genetic malformations. Thanks also to single-molecule experiments that have outreached an incredible development in the recent years, it has been discovered that not only chemical reactions, electrical signaling and thermal effects are involved in the proper effectiveness of such systems, but also mechanical forces play a crucial role. In this spirit, we derive a paradigmatic Peyrard-Bishop model describing the melting transition of double-stranded molecules such as DNA, tropocollagen fibers or neuronal microtubules and tau proteins bundles. We study the effect of mechanical forces, the role of temperature and the effect of an interacting device (AFM, ancilla molecule) through local mechanical interactions, and we analyze the cooperativity and toughness of the mechanically induced melting of these classes of molecules. We obtain the analytic dependence of the cooperative/non-cooperative behavior on a single parameter based the on physical quantities with crucial counterparts on the stability and reversibility of important melting phenomena. Moreover, we compare our theoretical results and analytical formulas with both molecular dynamic simulations and experiments performed on different molecules.

Add to your calendar

Download event information as iCalendar file (only this event)