Preparation and stability of pegylated poly(S-alkyl-L-homocysteine) coacervate core micelles in aqueous media.

We report development and preparation of synthetic polypeptide based, coacervate core polyelectrolyte complex micelles, PCMs, in aqueous media, which were characterized and evaluated for the encapsulation and in vitro release of a model single-stranded RNA, polyadenylic acid, poly(A). Cationic, α-helical polypeptides pegylated at their N-termini, PEG-b-5b and PEG-b-5c were designed to form coacervate core PCMs upon mixing with multivalent anions in aqueous media. Sodium tripolyphosphate (TPP) and poly(A) were used as model multivalent anions that allowed optimization of polypeptide composition and chain length for formation of stable, nanoscale PCMs.

Controlled Synthesis and Properties of Poly(l-homoserine).

We report the preparation of a new water-soluble, nonionic homopolypeptide poly(l-homoserine) as well as poly(l-homoserine) block copolymers with controllable segment lengths. The conformational preferences of poly(l-homoserine) were also determined in both the solid state and in solution. Poly(l-homoserine) is soluble in water and adopts a disordered conformation that makes it a promising addition to the small class of nonionic, water-soluble homopolypeptides with potential for development for applications in biology.

Poly(dehydroalanine): Synthesis, Properties, and Functional Diversification of a Fluorescent Polypeptide.

Via the design of a new, soluble poly(-alkyl-l-cysteine) precursor, a route was developed for the successful preparation of long-chain poly(dehydroalanine), , as well as the incorporation of dehydroalanine residues and segments into copolypeptides. Based on experimental and computational data, was found to adopt a previously unobserved "hybrid coil" structure, which combines the elements of 2-helical and 3-helical conformations. Analysis of the spectroscopic properties of revealed that it possesses a strong inherent blue fluorescence, which may be amenable for use in imaging applications.