Why this research matters
QTY code has been successfully used to significantly improve the solubility of water-insoluble integral transmembrane proteins. They include G protein-coupled receptors (GPCRs), cytokine receptors, glucose transporters, and solute carrier transporters through systematically replacing the hydrophobic leucine (L), valine (V), isoleucine (I), and phenylalanine (F) in the transmembrane domains by glutamine (Q), threonine (T), and tyrosine (Y).
Here we reverse the QTY code as the rQTY code to improve the hydrophobicity of the specific alpha-helices on HSA for self-assembly into well-defined nanoparticles. The rQTY code has significant implications for design of specific hydrophobic domains of highly water-soluble proteins to design their self-assembly for diverse applications including encapsulate hydrophobic drugs, receptor-mediated sustained drug release, and target drug transport across cell membranes.
Researchers have been doing controlled and sustained drug delivery for over four decades. These delivery technologies can be called “general delivery,” namely, the molecular medicine can be sustained and controlled delivery into the body for weeks, months, perhaps even years. These molecular drugs can go to most parts of the body. The current PNAS paper report is for “specific delivery” through the specific receptor-mediate delivery, like UPS or USPS delivery follows the specific zip code and specific location address. This current research could open a new avenue of study that will eventually lead to more targeted delivery to treat particularly diseased cells.