Influence of\nSide-Chain Molecular Features on Aqueous\nCoacervation of Multifunctional Homopolypeptides

Three different series of amino acid side-chain functionalized\nhomopolypeptides were prepared as variants of previously reported\nα-helical, coacervate-forming cationic polypeptides. Studies\nof the physical behavior of these polypeptides in aqueous media in\nthe presence of multivalent counterions enabled a better understanding\nof the molecular requirements for coacervate formation of side-chain\nfunctionalized homopolypeptides. Variation in lengths of side-chain\namino acid or linker segments in cationic α-helical polypeptides\nwas found either to prohibit coacervate formation or to allow adjustment\nof the phase transition temperature. A series of charge-reversed,\nanionic amino acid side-chain functionalized homopolypeptides were\nalso prepared and found to be α-helical and able to form coacervates\nsimilar to analogous cationic homopolypeptides. These results illustrate\nthe ability to predictably tune coacervation properties via molecular\nadjustment of side-chains in homopolypeptides and show that amino\nacid side-chain functionalized homopolypeptides can be used as a general\nplatform for development of biomimetic, coacervate-forming polymers.