A protein engineered to bind uranyl selectively and with femtomolar affinity

Zhou L., Bosscher M., Zhang C., Oezcubukcu S., Zhang L., Zhang W., ...More

NATURE CHEMISTRY, vol.6, no.3, pp.236-241, 2014 (SCI-Expanded) identifier identifier identifier

  • Publication Type: Article / Article
  • Volume: 6 Issue: 3
  • Publication Date: 2014
  • Doi Number: 10.1038/nchem.1856
  • Journal Name: NATURE CHEMISTRY
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.236-241
  • Middle East Technical University Affiliated: Yes

Abstract

Uranyl (UO22+), the predominant aerobic form of uranium, is present in the ocean at a concentration of similar to 3.2 parts per 10(9) (13.7 nM); however, the successful enrichment of uranyl from this vast resource has been limited by the high concentrations of metal ions of similar size and charge, which makes it difficult to design a binding motif that is selective for uranyl. Here we report the design and rational development of a uranyl-binding protein using a computational screening process in the initial search for potential uranyl-binding sites. The engineered protein is thermally stable and offers very high affinity and selectivity for uranyl with a K-d of 7.4 femtomolar (fM) and >10,000-fold selectivity over other metal ions. We also demonstrated that the uranyl-binding protein can repeatedly sequester 30-60% of the uranyl in synthetic sea water. The chemical strategy employed here may be applied to engineer other selective metal-binding proteins for biotechnology and remediation applications.