Enzymatic Surface-Initiated Polymerization:A Novel Approach for the in Situ Solid-Phase Synthesis of Biocompatible Polymer Poly(3-hydroxybutyrate)

摘要

A novel system for surface-initiated enzymatic polymerization of a film of polyhydroxyalkanoate (PHA) on solid surfaces has been developed and characterized.PHAs are aliphatic polyesters produced by a variety of microorganisms as a reserve of carbon and energy,and their properties range from elastomers to thermoplastics,depending on their monomeric composition.The PHA synthase from Ralstonia eutropha H16 was expressed as a poly-histidine fusion in Escherichia coli and immobilized onto several solid substrates through a transition-metal complex,Ni~(2+)-nitrilotriacetic acid.The immobilized PHA synthase catalyzed the surface-initiated polymerization of 3-(R)-hydroxybutyryl-CoA,forming a polymer film with a uniform thickness on the surface.In this work,we describe the patterned immobilization of the intact enzyme on silicon and subsequent enzymatic polymerization.The immobilized enzyme had a lower specific activity and did not exhibit a lag phase as compared to the soluble enzyme.