Evolution of proteins with genetically encoded "chemical warheads".
We recently developed a phage-based system for the evolution of proteins in bacteria with expanded amino acid genetic codes. Here we demonstrate that the unnatural amino acid p-boronophenylalanine (BF) confers a selective advantage in the evolution of glycan-binding proteins. We show that an unbiased library of naive antibodies with NNK-randomized V(H) CDR3 loops converges upon mutants containing BF when placed under selection for binding to a model acyclic amino sugar. This work represents a first step in the evolution of carbohydrate-binding proteins that use a reactive unnatural amino acid "warhead" and demonstrates that a "synthetic" genetic code can confer a selective advantage by increasing the number of functional groups available to evolution.
Liu
Chang C
CC
Department of Chemistry, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, California 92037, USA.
Mack
Antha V
AV
Brustad
Eric M
EM
Mills
Jeremy H
JH
Groff
Dan
D
Smider
Vaughn V
VV
Schultz
Peter G
PG
D000906:Antibodies / Q000276:immunology; D001896:Boron Compounds / Q000737:chemistry / Q000378:metabolism*; D018389:Codon, Nonsense; D004926:Escherichia coli; D029968:Escherichia coli Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D019143:Evolution, Molecular; D006801:Humans; D009154:Mutation; D010649:Phenylalanine / Q000031:analogs & derivatives* / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D011134:Polysaccharides / Q000276:immunology / Q000378:metabolism; D015202:Protein Engineering / Q000379:methods*; D012641:Selection, Genetic
D000906:Antibodies; D001896:Boron Compounds; D018389:Codon, Nonsense; D029968:Escherichia coli Proteins; D011134:Polysaccharides; D010649:Phenylalanine; C033685:4-boronophenylalanine