Engineering an ultra-stable affinity reagent based on top 7

  • Boschek C
  • Apiyo D
  • Soares T
 et al. 
  • 28


    Mendeley users who have this article in their library.
  • 16


    Citations of this article.


Antibodies are widely used for diagnostic and therapeutic applications because of their sensitive and specific recognition of a wide range of targets; however, their application is limited by their structural complexity. More demanding applications require greater stability than can be achieved by immunoglobulin-based reagents. Highly stable, protein-based affinity reagents are being investigated for this role with the goal of identifying a suitable scaffold that can attain specificity and sensitivity similar to that of antibodies while performing under conditions where antibodies fail. We have engineered Top7--a highly stable, computationally designed protein--to specifically bind human CD4 by inserting a peptide sequence derived from a CD4-specific antibody. Molecular dynamics simulations were used to evaluate the structural effect of the peptide insertion at a specific site within Top7 and suggest that this Top7 variant retains conformational stability over 100 degrees C. This engineered protein specifically binds CD4 and, consistent with simulations, is extremely resistant to thermal and chemical denaturation--retaining its secondary structure up to at least 95 degrees C and requiring 6 M guanidine to completely unfold. This CD4-specific protein demonstrates the functionality of Top7 as a viable scaffold for use as a general affinity reagent which could serve as a robust and inexpensive alternative to antibodies.

Author-supplied keywords

  • Engineering affinity
  • Molecular dynamics simulations
  • Protein scaffold
  • Protein stability
  • Top7

Get free article suggestions today

Mendeley saves you time finding and organizing research

Sign up here
Already have an account ?Sign in

Find this document

Get full text


  • Curt B. Boschek

  • David O. Apiyo

  • Thereza A. Soares

  • Heather E. Engelmann

  • Noah B. Pefaur

  • Tjerk P. Straatsma

Cite this document

Choose a citation style from the tabs below

Save time finding and organizing research with Mendeley

Sign up for free