Methodology article

Trinucleotide cassettes increase diversity of T7 phage-displayed peptide library

Lauren RH Krumpe^1,2†, Kathryn M Schumacher^1,3†, James B McMahon¹, Lee Makowski⁴ and Toshiyuki Mori^1*

• * Corresponding author: Toshiyuki Mori Mori_Toshiyuki2@takeda.co.jp

• † Equal contributors

Author Affiliations

¹ Molecular Targets Development Program, Center for Cancer Research, NCI-Frederick, Frederick, Maryland, 21702, USA

² SAIC-Frederick, Inc., NCI-Frederick, Frederick, Maryland 21702, USA

³ Werner H. Kirsten Student Internship Program, NCI-Frederick, Frederick, Maryland, 21702, USA

⁴ Biosciences Division, Argonne National Laboratory, Argonne, Illinois, 60439, USA

For all author emails, please log on.

BMC Biotechnology 2007, 7:65 doi:10.1186/1472-6750-7-65

Published: 5 October 2007

Abstract

Background

Amino acid sequence diversity is introduced into a phage-displayed peptide library by randomizing library oligonucleotide DNA. We recently evaluated the diversity of peptide libraries displayed on T7 lytic phage and M13 filamentous phage and showed that T7 phage can display a more diverse amino acid sequence repertoire due to differing processes of viral morphogenesis.

Methods

In this study, we evaluated and compared the diversity of a 12-mer T7 phage-displayed peptide library randomized using codon-corrected trinucleotide cassettes with a T7 and an M13 12-mer phage-displayed peptide library constructed using the degenerate codon randomization method.

Results

We herein demonstrate that the combination of trinucleotide cassette amino acid codon randomization and T7 phage display construction methods resulted in a significant enhancement to the functional diversity of a 12-mer peptide library. This novel library exhibited superior amino acid uniformity and order-of-magnitude increases in amino acid sequence diversity as compared to degenerate codon randomized peptide libraries. Comparative analyses of the biophysical characteristics of the 12-mer peptide libraries revealed the trinucleotide cassette-randomized library to be a unique resource.

Conclusion

The combination of T7 phage display and trinucleotide cassette randomization resulted in a novel resource for the potential isolation of binding peptides for new and previously studied molecular targets.