Intrinsically disordered proteins (IDPs) represent a unique and functionally significant class of biomolecules that play key regulatory roles in higher organisms. Unlike structured proteins, IDPs lack a fixed three-dimensional conformation, a feature that enables their dynamic interactions and allows their biochemical activity to be finely tuned by temperature and the cellular environment. From a biophysical perspective, IDPs behave as heteropolymers with extensive conformational flexibility, governed by non-covalent interactions among their amino acid side chains under specific physicochemical conditions.

In this seminar, I will discuss the fundamental physicochemical properties of proteins as heteropolymers, focusing on how hydrodynamic parameters relate to structural characteristics. I will highlight common challenges in interpreting the molecular properties of IDPs, in contrast to folded proteins. The talk will include recent findings from our research on interactions and liquid-liquid phase separation in two systems: cytoplasmic proteins involved in human gene expression and extracellular coral acid-rich proteins implicated in biomineralization, based on fluorescence correlation spectroscopy and confocal imaging.