title: Construction of polymer-protein bioconjugates with varying chain topologies: polymer molecular weight and steric hindrance effects.
abstract: We report on the fabrication of well-defined polymer-protein bioconjugates with varying chain architectures, including star polymers, star block copolymers, and heteroarm star copolymers through the specific noncovalent interaction between avidin and biotinylated synthetic polymer precursors. Homopolymer and diblock precursors site-specifically labeled with a single biotin moiety at the chain terminal, chain middle, or diblock junction point were synthesized by a combination of atom-transfer radical polymerization (ATRP) and click reactions. By taking advantage of molecular recognition between avidin and biotin moieties, supramolecular star polymers, star block copolymers, and heteroarm star copolymers were successfully fabricated. This specific binding process was also assessed by using the diffraction optic technology (DOT) technique. We further investigated the effects of polymer molecular weights, location of biotin functionality within the polymer chain, and polymer chain conformations, that is, steric hindrance effects, on the binding numbers of biotinylated polymer chains per avidin within the polymer-protein bioconjugates, which were determined by the standard avidin/2-(4-hydroxyazobenzene)benzoic acid (HABA) assay. The binding numbers vary in the range of 1.9-3.3, depending on the molecular weights, locations of biotin functionality within synthetic polymer precursors, and polymer chain conformations.
authors: CAS Key Laboratory of Soft Matter Chemistry, Department of Polymer Science and Engineering, University of Science and Technology of China, Hefei, Anhui 230026, P.R. China.
authors: Xuejuan
authors: X
authors: Wan
authors: Guoying
authors: G
authors: Zhang
authors: Zhishen
authors: Z
authors: Ge
authors: Ravin
authors: R
authors: Narain
authors: Shiyong
authors: S
authors: Liu
mesh_terms: D001360:Avidin / Q000737:chemistry*; D001710:Biotin / Q000737:chemistry*; D015394:Molecular Structure; D008970:Molecular Weight; D011108:Polymers / Q000138:chemical synthesis / Q000737:chemistry*; D011506:Proteins / Q000737:chemistry*; D013237:Stereoisomerism
chemical_list: D011108:Polymers; D011506:Proteins; D001360:Avidin; D001710:Biotin