Protein aggregation in the human body can cause a number of diseases, which makes it essential to study protein aggregation paths and mechanisms in order to find methods to treat them. This work is a continuation of the series of studies aimed at finding compounds capable of triggering protein aggregation in solutions. The aim of this work was to find a correlation between the structure, thermodynamic stability of BSA complexes with cationic macroheterocycles (MHC) and propensity of albumin complexes for aggregation, as well as the hydrodynamic properties of protein solutions. Meso-tetra-(N-methyl-4-pyridyl)porphine tetraiodide (TMPyP4), meso-tetra-(N-methyl-3-pyridyl)porphine tetraiodide (TMPyP3) and meso-tetra-(N-methyl-3-pyridyl)bacteriochlorin tetra tosylate (BC) trigger different types of BSA aggregation, depending on their localization in the albumin globule. When macroheterocycles are localized inside an albumin globule, they trigger sequential monomer addition, with both monomer structures and aggregates of medium and large sizes present in the solution. If a macroheterocycle is localized on the surface of a protein globule, protein aggregation is caused by the formation of macroheterocycle complexes with two or more globules.
