Polar residues, like aspartic acid, asparagine, glutamic acid, and glutamine, can create hydrogen bonds between membrane-embedded helices, influencing their self-association.
Research explored how these polar residues interact in various transmembrane domains, including naturally occurring proteins and modified bacteriophage proteins.
Results showed that while some polar residues can stabilize interactions between helices, there are instances where they do not enhance association, indicating a complex control mechanism at play.