Genetically encoded initiator for polymer growth from proteins.
Despite the importance of protein-polymer bioconjugates, there is no general method for producing homogeneous recombinant protein that contains polymer initiators at defined sites. To address this deficiency, we designed the amino acid 4-(2'-bromoisobutyramido)phenylalanine (1) as an initiator in atom-transfer radical polymerization (ATRP) that would provide a stable linkage between the protein and growing polymer. We synthesized 1 and evolved a Methanococcus jannaschii tyrosyl-tRNA synthetase/tRNA(CUA) pair to genetically encode this initiator in response to an amber codon. To demonstrate the utility of this initiator, we produced green fluorescent protein (GFP) with 1 site-specifically incorporated on its surface (GFP-1). Purified GFP-1 was then used as an initiator under standard ATRP conditions with a monomer, oligo(ethylene oxide) monomethyl ether methacrylate, efficiently producing a polymer-GFP bioconjugate where the polymer is connected at our selected site on GFP.
Peeler
Jennifer C
JC
Department of Chemistry, Franklin & Marshall College, Lancaster, Pennsylvania 17604-3003, USA.
Woodman
Bradley F
BF
Averick
Saadyah
S
Miyake-Stoner
Shigeki J
SJ
Stokes
Audrey L
AL
Hess
Kenneth R
KR
Matyjaszewski
Krzysztof
K
Mehl
Ryan A
RA
D001704:Biopolymers / Q000737:chemistry; D049452:Green Fluorescent Proteins / Q000737:chemistry*; D017017:Methanococcus / Q000201:enzymology*; D015394:Molecular Structure; D010649:Phenylalanine / Q000031:analogs & derivatives* / Q000138:chemical synthesis* / Q000737:chemistry; D013499:Surface Properties; D014448:Tyrosine-tRNA Ligase / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*
C555111:4-(2'-bromoisobutyroamido)phenylalanine; D001704:Biopolymers; D049452:Green Fluorescent Proteins; D010649:Phenylalanine; D014448:Tyrosine-tRNA Ligase