title: Facile synthesis of block copolypeptides of defined architecture.
abstract: Many natural polymeric materials (particularly structural proteins) display a hierarchy of structure over several length scales. Block copolymers are able to self-assemble into ordered nanostructures, but the random-coiled nature of their polymer chains usually suppresses any further levels of organization. The use of components with regular structures, such as rigid-rod polymers, can increase the extent of spatial organization in self-assembling materials. But the synthesis of such polymeric components typically involves complicated reaction steps that are not suitable for large-scale production. Proteins form hierarchically organized structures in which the fundamental motifs are generally alpha-helical coils and beta-sheets. Attempts to synthesize polypeptides with well-defined amino-acid sequences, which might adopt similar organized structures, have been plagued by unwanted side reactions that give rise to products with a wide range of molecular weights, hampering the formation of well-defined peptide block copolymers. Here I describe a polymerization strategy that overcomes these difficulties by using organonickel initiators which suppress chain-transfer and termination side reactions. This approach allows the facile synthesis of block copolypeptides with well-defined sequences, which might provide new peptide-based biomaterials with potential applications in tissue engineering, drug delivery and biomimetic composite formation.
authors.affiliation: Department of Materials, University of California, Santa Barbara 93106, USA. tdeming@engineering.ucsb.edu
authors.forename: T J
authors.initials: TJ
authors.lastname: Deming
mesh_terms: D000596:Amino Acids / Q000737:chemistry; D001704:Biopolymers; D008239:Lysine / Q000031:analogs & derivatives / Q000138:chemical synthesis / Q000737:chemistry; D009942:Organometallic Compounds / Q000737:chemistry*; D010455:Peptides / Q000138:chemical synthesis*; D011099:Polyglutamic Acid / Q000031:analogs & derivatives / Q000138:chemical synthesis / Q000737:chemistry
chemical_list: D000596:Amino Acids; D001704:Biopolymers; D009942:Organometallic Compounds; D010455:Peptides; C003172:poly-gamma-benzyl-L-glutamate; D011099:Polyglutamic Acid; D008239:Lysine