Beyond Helper Phage: Using "Helper Cells" to Select Peptide Affinity Ligands.
Peptides are important affinity ligands for microscopy, biosensing, and targeted delivery. However, because they can have low affinity for their targets, their selection from large naïve libraries can be challenging. When selecting peptidic ligands from display libraries, it is important to: 1) ensure efficient display; 2) maximize the ability to select high affinity ligands; and 3) minimize the effect of the display context on binding. The "helper cell" packaging system has been described as a tool to produce filamentous phage particles based on phagemid constructs with varying display levels, while remaining free of helper phage contamination. Here we report on the first use of this system for peptide display, including the systematic characterization and optimization of helper cells, their inefficient use in antibody display and their use in creating and selecting from a set of phage display peptide libraries. Our libraries were analyzed with unprecedented precision by standard or deep sequencing, and shown to be superior in quality than commercial gold standards. Using our helper cell libraries, we have obtained ligands recognizing Yersinia pestis surface antigen F1V and L-glutamine-binding periplasmic protein QBP. In the latter case, unlike any of the peptide library selections described so far, we used a combination of phage and yeast display to select intriguing peptide ligands. Based on the success of our selections we believe that peptide libraries obtained with helper cells are not only suitable, but preferable to traditional phage display libraries for selection of peptidic ligands.
Center for Integrated Nanotechnologies, Los Alamos National Laboratory, Los Alamos, NM 87545, United States of America.
M Lisa
ML
Phipps
Bioscience Division, Los Alamos National Laboratory, Los Alamos, NM 87545, United States of America.
Antoinetta M
AM
Lillo
Bioscience Division, Los Alamos National Laboratory, Los Alamos, NM 87545, United States of America.
Yulin
Y
Shou
Bioscience Division, Los Alamos National Laboratory, Los Alamos, NM 87545, United States of America.
Emily N
EN
Schmidt
Space Biosciences Division, National Aeronautics and Space Administration Ames Research Center, Moffett Field, CA 94035, United States of America.
Chad D
CD
Paavola
Bioscience Division, Los Alamos National Laboratory, Los Alamos, NM 87545, United States of America.
Leslie
L
Naranjo
Bioscience Division, Los Alamos National Laboratory, Los Alamos, NM 87545, United States of America.
Sara
S
Bemdich
Bioscience Division, Los Alamos National Laboratory, Los Alamos, NM 87545, United States of America.
Basil I
BI
Swanson
Bioscience Division, Los Alamos National Laboratory, Los Alamos, NM 87545, United States of America.
Andrew R M
AR
Bradbury
Center for Integrated Nanotechnologies, Los Alamos National Laboratory, Los Alamos, NM 87545, United States of America.|Institute for Materials Science, Los Alamos National Laboratory, Los Alamos, NM 87545, United States of America.
Jennifer S
JS
Martinez
D000942:Antigens, Bacterial / Q000378:metabolism; D017104:Bacteriophage M13 / Q000378:metabolism*; D004926:Escherichia coli / Q000378:metabolism; D005434:Flow Cytometry; D008024:Ligands; D019151:Peptide Library; D010455:Peptides / Q000378:metabolism*; D012441:Saccharomyces cerevisiae / Q000378:metabolism; D015010:Yersinia pestis / Q000378:metabolism
D000942:Antigens, Bacterial; D008024:Ligands; D019151:Peptide Library; D010455:Peptides