title: Introduction of plasmid encoding for rare tRNAs reduces amplification bias in phage display biopanning.
abstract: Amplification bias is a major hurdle in phage display protocols because it imparts additional, unintended selection pressure beyond binding to the desired target. One potential source of amplification bias is the inherent lack of codon optimization that occurs within phage display libraries. Here we present a method that reduces amplification bias by addition of a plasmid that encodes six low abundance tRNAs into K91 Escherichia coli. This new strain, termed K91+, is used to amplify phage during the selection process. We demonstrate the importance of rare codon usage in phage production, and our method produced an overall increase in uniformity of phage production in a random library. Both of these variables are improved in E. coli K91+ compared with the parental K91 strain. This simple solution, requiring only a commercially available plasmid and an additional antibiotic, can reduce amplification bias in phage display protocols.
authors: SRI International, Center for Chemical Biology, Harrisonburg, VA.|UT Southwestern Medical Center, Dallas, TX.
authors: Benjamin J
authors: BJ
authors: Umlauf
authors: SRI International, Center for Chemical Biology, Harrisonburg, VA.
authors: Michael J
authors: MJ
authors: McGuire
authors: SRI International, Center for Chemical Biology, Harrisonburg, VA.
authors: Kathlynn C
authors: KC
authors: Brown
mesh_terms: D000595:Amino Acid Sequence; D015982:Bias; D061505:Cell Surface Display Techniques / Q000379:methods*; D003062:Codon / Q000235:genetics; D008969:Molecular Sequence Data; D021141:Nucleic Acid Amplification Techniques; D010455:Peptides / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D010957:Plasmids / Q000235:genetics*; D012343:RNA, Transfer / Q000235:genetics*; D014170:Transformation, Genetic
chemical_list: D003062:Codon; D010455:Peptides; D012343:RNA, Transfer
keywords: amplification bias; biopanning; codon bias; combinatorial peptide libraries; peptide; phage display
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