A Simple Methodology for the Synthesis of Heterotelechelic Protein-Polymer-Biomolecule Conjugates

作者：Liu Jingquan; Liu Huiyun; Bulmus Volga; Tao Lei; Boyer Cyrille; Davis Thomas P^*

来源：Journal of Polymer Science Part A: Polymer Chemistry , 2010, 48(6): 1399-1405.

DOI：10.1002/pola.23902

• biological applications of polymers
• BSA
• cholesterol
• in situ polymerization
• protein-polymer conjugates
• radical polymerization
• RAFT
• telechelics

A synthetic protocol for the preparation of hetero-biofunctional protein-polymer conjugates is described. A chain transfer agent, SS-bis (alpha,alpha';-dimethyl-alpha ';';-acetic acid) trithiocarbonate was functionalized with alpha,omega-pyridyl disulfide (PDS) groups, Subsequently, one of the PDS groups was covalently attached to bovine serum albumin (BSA) at the specific free thiol group on the cysteine residue through a disulfide linkage. The second PDS group remained intact, as it was found to be inaccessible to further BSA functionalization. The BSA-macro-reversible addition-fragmentation chain transfer (RAFT) agent was then used to prepare BSA-polymer conjugates via in situ polymerization of oligo (ethyleneglycol) acrylate and N-(2-hydroxypropyl) methacrylamide using an ambient temperature initiator, 4,4';-azobis [2,9-imidazolin-2-ethyl)propane] dihydrochloride in an aqueous medium. Sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE) confirmed that the in situ polymerization occurred at the protein surface where the RAFT agent was attached and the molecular weights of the BSA-polymer conjugates were found to increase concomitantly with monomer conversion and polymerization time. After polymerization the remaining terminal PDS groups were then utilized to attach thiocholesterol and a flurophore, rhodamine B to the protein-polymer conjugates via disulfide coupling. UV-Vis and fluorescence analyses revealed that similar to 80% of the protein conjugates were found to retain integral PDS end groups for further attachment to free thiol-tethered precursors.

• 出版日期2010-3-15