Hyperbranched polylysines: Mechanism of formation

Abstract

To gain insight into the mechanism treating formation of hyperbranched polylysines through the polymerization of N ɛ-carbobenzoxylysine N-carboxyanhydride under conditions of the reductive removal of a N ɛ-carbobenzoxy group, hyperbranched polylysine has been synthesized with the use of trifluoroacetic acid as a terminator in the polymerization of N-carboxyanhydride. The structure of the polymers is studied by capillary electrophoresis, low-pressure gel-permeation chromatography, circular dichroism, and enzymatic hydrolysis with trypsin. At the first stage of synthesis, a low-molecular-mass strongly branched core of the polymer is formed. At the second stage, polylysine chains are grafted via one point onto amino groups of N-terminal lysine moieties of the low-molecular-mass core through their carboxyl ends.