title: Effects of thermoresponsive coacervation on the hydrolytic degradation of amphipathic poly(gamma-glutamate)s.
abstract: Hydrolytic properties of thermoresponsive biopolymers with amphiphilic structures, gamma-PGA-P, were investigated. Hydrolysis was monitored in terms of molecular weight changes using GPC and spectroscopic measurements. The hydrolytic degradation of gamma-PGA-P was controlled by a change in the degree of propyl group conversion, reaction temperature, and/or reaction pH. The degradation was classified as the rapid elimination of propyl side chains and the moderate cleavage of peptide linkages in the backbone. Furthermore, hydrophobic environments established by the thermoresponsive coacervation of gamma-PGA-P60 solutions inhibited hydrolytic degradation reactions. Inversely, hydrolytic degradations increased coacervation temperatures. Kinetic studies of hydrolytic reactions suggest that the degradation rate of gamma-PGA-P60 solutions can be controlled by their thermoresponsivity. The hydrolysis reported here represents the first degradation rate controlled by thermoresponsive coacervation.
authors.affiliation: Department of Applied Chemistry, Graduate School of Engineering, Osaka University, 2-1 Yamada-oka Suita, 565-0871, Japan.
authors.forename: Taiki
authors.initials: T
authors.lastname: Shimokuri
authors.forename: Tatsuo
authors.initials: T
authors.lastname: Kaneko
authors.forename: Mitsuru
authors.initials: M
authors.lastname: Akashi
mesh_terms: D006863:Hydrogen-Ion Concentration; D006868:Hydrolysis; D009682:Magnetic Resonance Spectroscopy; D015394:Molecular Structure; D011099:Polyglutamic Acid / Q000737:chemistry*; D013696:Temperature; D013997:Time Factors
chemical_list: D011099:Polyglutamic Acid