Artificial Avidin-Based Receptors for a Panel of Small Molecules

ACS Chem Biol. 2016 Jan 15;11(1):211-21. doi: 10.1021/acschembio.5b00906. Epub 2015 Nov 23.

Abstract

Proteins with high specificity, affinity, and stability are needed for biomolecular recognition in a plethora of applications. Antibodies are powerful affinity tools, but they may also suffer from limitations such as low stability and high production costs. Avidin and streptavidin provide a promising scaffold for protein engineering, and due to their ultratight binding to D-biotin they are widely used in various biotechnological and biomedical applications. In this study, we demonstrate that the avidin scaffold is suitable for use as a novel receptor for several biologically active small molecules: Artificial, chicken avidin-based proteins, antidins, were generated using a directed evolution method for progesterone, hydrocortisone, testosterone, cholic acid, ketoprofen, and folic acid, all with micromolar to nanomolar affinity and significantly reduced biotin-binding affinity. We also describe the crystal structure of an antidin, sbAvd-2(I117Y), a steroid-binding avidin, which proves that the avidin scaffold can tolerate significant modifications without losing its characteristic tetrameric beta-barrel structure, helping us to further design avidin-based small molecule receptors.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Avidin / chemistry
  • Avidin / metabolism*
  • Biological Assay / methods*
  • Calorimetry, Differential Scanning
  • Chickens
  • Crystallography, X-Ray
  • Fluorometry
  • Models, Molecular
  • Molecular Dynamics Simulation
  • Molecular Structure
  • Receptors, Artificial / chemistry
  • Receptors, Artificial / drug effects*
  • Small Molecule Libraries / chemistry
  • Small Molecule Libraries / metabolism*

Substances

  • Receptors, Artificial
  • Small Molecule Libraries
  • Avidin