Impact of phenylalanines outside the dimer interface on phosphotriesterase stability and function

Andrew J. Olsen, Leif A. Halvorsen, Ching Yao Yang, Roni Barak Ventura, Liming Yin, P. Douglas Renfrew, Richard Bonneau, Jin Kim Montclare

Research output: Contribution to journalArticle

Abstract

We explore the significance of phenylalanine outside of the phosphotriesterase (PTE) dimer interface through mutagenesis studies and computational modeling. Previous studies have demonstrated that the residue-specific incorporation of para-fluorophenylalanine (pFF) into PTE improves stability, suggesting the importance of phenylalanines in stabilization of the dimer. However, this comes at a cost of decreased solubility due to pFF incorporation into other parts of the protein. Motivated by this, eight single solvent-exposed phenylalanine mutants are evaluated viarosetta and good correspondence between experiments and these predictions is observed. Three residues, F304, F327, and F335, appear to be important for PTE activity and stability, even though they do not reside in the dimer interface region or active site. While the remaining mutants do not significantly affect structure or activity, one variant, F306L, reveals improved activity at ambient and elevated temperatures. These studies provide further insight into role of these residues on PTE function and stability.

Original languageEnglish (US)
Pages (from-to)2092-2106
Number of pages15
JournalMolecular BioSystems
Volume13
Issue number10
DOIs
StatePublished - Jan 1 2017

    Fingerprint

ASJC Scopus subject areas

  • Biotechnology
  • Molecular Biology

Cite this