Structural characterization and visualization of oligomeric states of the Rhagium mordax antifreeze protein

Some organisms produce antifreeze proteins (AFPs) that help them survive freezing by binding to ice crystals. The molecular basis of this process is not yet fully elucidated. We suggest that the activity of these natural proteins is equivalent to the area of the ice-binding surface. The study focuses on a protein from R. mordax ( Rm AFP). It has one threonine motif required for ice binding. Our findings propose that oligomerization of Rm AFP increases the abundance of this motif and we show present of oligomeric structures in solution by mass spectrometry. We proposed potential structures for oligomers, which have a flat surface area necessary for ice binding. We have also demonstrated the presence of oligomeric forms of protein using atomic force microscopy. In addition, a model of oligomer Rm AFP binding to ice surfaces has been offered. The findings of this study suggest that a molecule comprising multiple Rm AFP domains in an oligomeric complex may possess augmented ice-binding capacity, which could potentially enhance the survival of the beetle Rhagium mordax in harsh winter conditions.