Mutations in fd phage major coat protein modulate affinity of the displayed peptide.
Multibillion-clone libraries of phages displaying guest peptides fused to the major coat protein pVIII (landscape libraries) are a rich source of probes for proteinaceous and non-proteinaceous targets. As opposed to the pIII-type fusion phages, which display peptides as independent structural domains, the guest peptides in the pVIII-fusion phages can be structurally and functionally influenced by contiguous subunits. To decipher the impact of the locale of a guest peptide on its affinity characteristics, we constructed a library of phages carrying beta-galactosidase-binding peptide ADTFAKSMQ at the N-terminus of the pVIII protein surrounded by random amino acids. It was found that mutagenesis of amino acids 12-19 (domain C) has polar effects on target binding affinity of the displayed peptide. The phages with highest affinity are characterized by: (i) a net electrostatic charge around -1 of domain C of the mutated phages at pH 7.0; (ii) a lower radius of cylinder coaxial to alpha-helix formed by domain C; (iii) a lower higher occupied molecular orbital (HOMO) of domain C leading to a decreased formation of hydrogen bonds and (iv) positively charged surface and torsion energy of domain C, which may require a conformational transition of N-terminal peptide ADTFAKSMQ for its binding with beta-galactosidase. Influence of the guest peptide on the diversity of mutations in the neighboring landscape area was also observed.
Kuzmicheva
G A
GA
Department of Pathobiology, Auburn University, 252 Greene Hall, College of Veterinary Medicine, Auburn, AL 36849, USA.
Jayanna
P K
PK
Eroshkin
A M
AM
Grishina
M A
MA
Pereyaslavskaya
E S
ES
Potemkin
V A
VA
Petrenko
V A
VA
D000595:Amino Acid Sequence; D017104:Bacteriophage M13 / Q000235:genetics*; D001435:Bacteriophages / Q000235:genetics; D001483:Base Sequence; D036022:Capsid Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D008958:Models, Molecular; D008969:Molecular Sequence Data; D009154:Mutation; D019151:Peptide Library; D010455:Peptides / Q000235:genetics* / Q000378:metabolism; D011485:Protein Binding; D001616:beta-Galactosidase / Q000737:chemistry / Q000235:genetics / Q000378:metabolism
D036022:Capsid Proteins; D019151:Peptide Library; D010455:Peptides; C119217:coat protein pVIII, Enterobacteria phage fd; D001616:beta-Galactosidase