Harnessing calcineurin-FK506-FKBP12 crystal structures from invasive fungal pathogens to develop antifungal agents.

Published online

Journal Article

Calcineurin is important for fungal virulence and a potential antifungal target, but compounds targeting calcineurin, such as FK506, are immunosuppressive. Here we report the crystal structures of calcineurin catalytic (CnA) and regulatory (CnB) subunits complexed with FK506 and the FK506-binding protein (FKBP12) from human fungal pathogens (Aspergillus fumigatus, Candida albicans, Cryptococcus neoformans and Coccidioides immitis). Fungal calcineurin complexes are similar to the mammalian complex, but comparison of fungal and human FKBP12 (hFKBP12) reveals conformational differences in the 40s and 80s loops. NMR analysis, molecular dynamic simulations, and mutations of the A. fumigatus CnA/CnB-FK506-FKBP12-complex identify a Phe88 residue, not conserved in hFKBP12, as critical for binding and inhibition of fungal calcineurin. These differences enable us to develop a less immunosuppressive FK506 analog, APX879, with an acetohydrazine substitution of the C22-carbonyl of FK506. APX879 exhibits reduced immunosuppressive activity and retains broad-spectrum antifungal activity and efficacy in a murine model of invasive fungal infection.

Full Text

Duke Authors

Cited Authors

  • Juvvadi, PR; Fox, D; Bobay, BG; Hoy, MJ; Gobeil, SMC; Venters, RA; Chang, Z; Lin, JJ; Averette, AF; Cole, DC; Barrington, BC; Wheaton, JD; Ciofani, M; Trzoss, M; Li, X; Lee, SC; Chen, Y-L; Mutz, M; Spicer, LD; Schumacher, MA; Heitman, J; Steinbach, WJ

Published Date

  • September 19, 2019

Published In

Volume / Issue

  • 10 / 1

Start / End Page

  • 4275 -

PubMed ID

  • 31537789

Pubmed Central ID

  • 31537789

Electronic International Standard Serial Number (EISSN)

  • 2041-1723

Digital Object Identifier (DOI)

  • 10.1038/s41467-019-12199-1

Language

  • eng

Conference Location

  • England